We disable hoptplug detection when we encounter a hotplug event
storm. Still hotplug detection is required on some outputs (like
Display Port). The interrupt storm may be only temporary (on certain
Dell Laptops for instance it happens at certain charging states of
the system). Thus we enable it after a certain grace period (2 minutes).
Should the interrupt storm persist it will be detected immediately
and it will be disabled again.
v2: Reordered drm_i915_private: moved hotplug_reenable_timer to hpd state tracker.
v3: Clarified loop start value,
Removed superfluous test for Ivybridge and Haswell,
Restructured loop to avoid deep nesting (all suggested by Ville Syrjälä)
v4: Fixed two bugs pointed out by Jani Nikula.
Signed-off-by: Egbert Eich <eich@suse.de>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This patch disables hotplug interrupts if an 'interrupt storm'
has been detected.
Noise on the interrupt line renders the hotplug interrupt useless:
each hotplug event causes the devices to be rescanned which will
will only increase the system load.
Thus disable the hotplug interrupts and fall back to periodic
device polling.
v2: Fixed cleanup typo.
v3: Fixed format issues, clarified a variable name,
changed pr_warn() to DRM_INFO() as suggested by
Jani Nikula <jani.nikula@linux.intel.com>.
Signed-off-by: Egbert Eich <eich@suse.de>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
To disable previously enabled HPD IRQs we need to reset them and
set the enabled ones individually.
Signed-off-by: Egbert Eich <eich@suse.de>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
When an encoder is shared on several connectors there is only
one hotplug line, thus this line needs to be shared among these
connectors.
If HPD detect only works reliably on a subset of those connectors,
we want to poll the others. Thus we need to make sure that storm
detection doesn't mess up the settings for those connectors.
Therefore we store the settings in the intel_connector struct and
restore them from there.
If nothing is set but the encoder has a hpd_pin set we assume this
connector is hotplug capable.
On init/reset we make sure the polled state of the connectors
is (re)set to the default value, the HPD interrupts are marked
enabled.
Signed-off-by: Egbert Eich <eich@suse.de>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Add a hotplug IRQ storm detection (triggered when a hotplug interrupt
fires more than 5 times / sec).
Rationale:
Despite of the many attempts to fix the problem with noisy hotplug
interrupt lines we are still seeing systems which have issues:
Once cause of noise seems to be bad routing of the hotplug line
on the board: cross talk from other signals seems to cause erronous
hotplug interrupts. This has been documented as an erratum for the
the i945GM chipset and thus hotplug support was disabled for this
chipset model but others seem to have this problem, too.
We have seen this issue on a G35 motherboard for example:
Even different motherboards of the same model seem to behave
differently: while some only see only around 10-100 interrupts/s
others seem to see 5k or more.
We've also observed a dependency on the selected video mode.
Also on certain laptops interrupt noise seems to occur duing
battery charging when the battery is at a certain charge levels.
Thus we add a simple algorithm here that detects an 'interrupt storm'
condition.
v2: Fixed comment.
v3: Reordered drm_i915_private: moved hpd state tracking to hotplug work stuff.
v4: Followed by Jesse Barnes to use a time_..() macro.
v5: Fixed coding style as suggested by Jani Nikula.
Signed-off-by: Egbert Eich <eich@suse.de>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Increase the number of fence registers to 32 on IVB/HSW. VLV however
only has 16 fence registers according to the docs.
Increasing the number of fences was attempted before [1], but there was
some uncertainty about the maximum CPU fence number for FBC. Since then
BSpec has been updated to state that there are in fact 32 fence registers,
and the CPU fence number field in the SNB_DPFC_CTL_SA register is 5 bits,
and the CPU fence number field in the ILK_DPFC_CONTROL register must be
zero. So now it all makes sense.
[1] http://lists.freedesktop.org/archives/intel-gfx/2011-October/012865.html
v2: Include some background information based on the previous attempt
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Interrupts, clock gating, LVDS, and GMBUS are all within the, "this will
be bad for CPU" range when we have PCH_NOP.
There is a bit of a hack in init clock gating. We want to do most of the
clock gating, but the part we skip will hang the system. It could
probably be abstracted a bit better, but I don't feel it's too
unsightly.
v2: Use inverse HAS_PCH_NOP check (Jani)
v3: Actually do what I claimed in v2 (spotted by Daniel)
Merge Ivybridge IRQ handler PCH check to decrease whitespace (Daniel)
Move LVDS bail into this patch (Ben)
v4: logical rebase conflict resolution with SDEIIR (Ben)
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Brush up patch a bit and resolve conflicts:
- Adjust PCH_NOP checks due to Egbert's hpd handling rework.
- Addd a PCH_NOP check in the irq uninstall code.
- Resolve conflicts with Paulo's SDE irq handling race fix.
v5: Drop the added hunks in the ilk irq handler again, they're bogus.
OOps.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
- It's a static function
- I just added a few more users to it
- Its sister ironlake_enable_display_irq is not marked as inline
- The compiler will still inline if it thinks it should do
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Now with Egbert Eich's hpd infrastructure rework merged this is dead
simple. And we need this to make output detection work on SDVO - with
the cleaned-up drm polling helpers outputs which claim to have hpd
support are no longer polled.
Now SDVO claims to do that, but it's not actually wired up. So just do
it.
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Noticed while reviewing the hotplug irq setup code. Just looks better.
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
After
"Convert HPD interrupts to make use of HPD pin assignment in encoders."
This function is now basically the same as i915_hpd_irq_setup().
Consolidating both functions in one requires one more check for
I915_HAS_HOTPLUG(dev) in the i965 code path and one more check for
IS_G4X(dev) in the i915 code path. These are considered harmless.
Signed-off-by: Egbert Eich <eich@suse.de>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
[danvet: Fixup patch conflict and make it compile.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This fixes a regression introduced in
commit e5868a318d
Author: Egbert Eich <eich@suse.de>
Date: Thu Feb 28 04:17:12 2013 -0500
DRM/i915: Convert HPD interrupts to make use of HPD pin assignment in encode
Due to the irq setup rework in 3.9, see
commit 20afbda209
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Tue Dec 11 14:05:07 2012 +0100
drm/i915: Fixup hpd irq register setup ordering
Egbert Eich's hpd rework blows up on pch-split platforms - it walks
the encoder list before that has been set up completely. The new init
sequence is:
1. irq enabling
2. modeset init
3. hpd setup
We need to move around the ibx setup a bit to fix this.
Ville Syrjälä pointed out in his review that we can't touch SDEIER
after the interrupt handler is set up, since that'll race with Paulo
Zanoni's PCH interrupt race fix:
commit 44498aea29
Author: Paulo Zanoni <paulo.r.zanoni@intel.com>
Date: Fri Feb 22 17:05:28 2013 -0300
drm/i915: also disable south interrupts when handling them
We fix that by unconditionally enabling all interrupts in SDEIER, but
masking them as-needed in SDEIMR. Since only the single-threaded
setup/teardown (or suspend/resume) code touches that, no further
locking is required.
While at it also simplify the mask handling - we start out with all
interrupts cleared in the postinstall hook, and never enable a hpd
interrupt before hpd_irq_setup is called.
And finally, for consistency rename the ibx hpd setup function to
ibx_hpd_irq_setup.
v2: Fix race around SDEIER writes (Ville).
v3: Remove the superflous posting read for SDEIER, spotted by Ville.
Ville also wondered whether we shouldn't clear SDEIIR, since now
SDE interrupts are enabled before we have an irq handler installed.
But the master interrupt control bit in DEIER is still cleared, so we
should be fine.
Cc: Egbert Eich <eich@suse.de>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=62798
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This allows to enable HPD interrupts for individual pins to only receive
hotplug events from lines which are connected and working.
v2: Restructured initailization of const arrays following a suggstion
by Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Egbert Eich <eich@suse.de>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org> (v1)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
So don't read it when capturing the error state. This solves
"unclaimed register" messages on Haswell when we have a GPU hang.
V2: Check for HAS_PCH_SPLIT instead of Gen5+ because VLV still has
this register.
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
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Merge tag 'v3.9-rc3' into drm-intel-next-queued
Backmerge so that I can merge Imre Deak's coalesced sg entries fixes,
which depend upon the new for_each_sg_page introduce in
commit a321e91b6d
Author: Imre Deak <imre.deak@intel.com>
Date: Wed Feb 27 17:02:56 2013 -0800
lib/scatterlist: add simple page iterator
The merge itself is just two trivial conflicts:
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Once we thought we got semaphores working, we disabled kicking the ring
if hangcheck fired whilst waiting upon a ring as it was doing more harm
than good:
commit 4e0e90dcb8
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Wed Dec 14 13:56:58 2011 +0100
drm/i915: kicking rings stuck on semaphores considered harmful
However, life is never that easy and semaphores are still causing
problems whereby the value written by one ring (bcs) is not being
propagated to the waiter (rcs). Thus the waiter never wakes up and we
declare the GPU hung, which often has unfortunate consequences, even if
we successfully reset the GPU.
But the GPU is idle as it has completed the work, just didn't notify its
clients. So we can detect the incomplete wait during hang check and
probe the target ring to see if has indeed emitted the breadcrumb seqno
following the work and then and only then kick the waiter.
Based on a suggestion by Ben Widawsky.
v2: cross-check wait with iphdr. fix signaller calculation.
References: https://bugs.freedesktop.org/show_bug.cgi?id=54226
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Ben Widawsky <ben@bwidawsk.net>
Acked-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
To avoid this:
[ 256.798060] [drm] capturing error event; look for more information
in/sys/kernel/debug/dri/0/i915_error_state
Ben Widawsky identified that this regression has been introduced in
commit 2f86f19165
Author: Ben Widawsky <ben@bwidawsk.net>
Date: Mon Jan 28 15:32:15 2013 -0800
drm/i915: Error state should print /sys/kernel/debug
...
[danvet: split up long line.] <----- he did it
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
[danvet: Pimp commit message with the regression note. Also, order
more brown paper bags, I've run out.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
From the docs:
"IIR can queue up to two interrupt events. When the IIR is cleared,
it will set itself again after one clock if a second event was
stored."
"Only the rising edge of the PCH Display interrupt will cause the
North Display IIR (DEIIR) PCH Display Interrupt even bit to be set,
so all PCH Display Interrupts, including back to back interrupts,
must be cleared before a new PCH Display interrupt can cause DEIIR
to be set".
The current code works fine because we don't get many interrupts, but
if we enable the PCH FIFO underrun interrupts we'll start getting so
many interrupts that at some point new PCH interrupts won't cause
DEIIR to be set.
The initial implementation I tried was to turn the code that checks
SDEIIR into a loop, but we can still get interrupts even after the
loop is done (and before the irq handler finishes), so we have to
either disable the interrupts or mask them. In the end I concluded
that just disabling the PCH interrupts is enough, you don't even need
the loop, so this is what this patch implements. I've tested it and it
passes the 2 "PCH FIFO underrun interrupt storms" I can reproduce:
the "ironlake_crtc_disable" case and the "wrong watermarks" case.
In other words, here's how to reproduce the problem fixed by this
patch:
1 - Enable PCH FIFO underrun interrupts (SERR_INT on SNB+)
2 - Boot the machine
3 - While booting we'll get tons of PCH FIFO underrun interrupts
4 - Plug a new monitor
5 - Run xrandr, notice it won't detect the new monitor
6 - Read SDEIIR and notice it's not 0 while DEIIR is 0
Q: Can't we just clear DEIIR before SDEIIR?
A: It doesn't work. SDEIIR has to be completely cleared (including the
interrupts stored on its back queue) before it can flip DEIIR's bit to
1 again, and even while you're clearing it you'll be getting more and
more interrupts.
Q: Why does it work by just disabling+enabling the south interrupts?
A: Because when we re-enable them, if there's something on the SDEIIR
register (maybe an interrupt stored on the queue), the re-enabling
will make DEIIR's bit flip to 1, and since we'll already have
interrupts enabled we'll get another interrupt, then run our irq
handler again to process the "back" interrupts.
v2: Even bigger commit message, added code comments.
Note that this fixes missed dp aux irqs which have been reported for
3.9-rc1. This regression has been introduced by switching to
irq-driven dp aux transactions with
commit 9ee32fea5f
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Sat Dec 1 13:53:48 2012 +0100
drm/i915: irq-drive the dp aux communication
References: http://www.mail-archive.com/intel-gfx@lists.freedesktop.org/msg18588.html
References: https://lkml.org/lkml/2013/2/26/769
Tested-by: Imre Deak <imre.deak@intel.com>
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
[danvet: Pimp commit message with references for the dp aux irq
timeout regression this fixes.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
On error, this represents the state of the currently running context at
the time it was loaded.
Unfortunately, since we're hung and can't switch out the context this
may not tell us too much about the most current state of the context,
but does give clues about what has happened since loading.
Thanks to recent doc updates, we have a little more confidence regarding
what is actually in this memory, and perhaps it will help us gain more
insight into certain bugs. AFAICT, the most interesting info is in the
first page. To save space, we only capture the first page. In the
future, we might want to dump more.
Sample of the relevant part of error state:
render ring --- HW Context = 0x01b20000
[0000] 00000000 1100105f 00002028 ffff0880
[0010] 0000209c feff4040 000020c0 efdf0080
[0020] 00002178 00000001 0000217c 00145855
[0030] 00002310 00000000 00002314 00000000
v2: Move error collection to the ring error code
Change format of dump to not confuse intel_error_decode (Chris)
Put the context error object with the others (Chris)
Don't search bound_list instead of active_list (chris)
v3: extract and flatten context recording (daniel)
checkpatch related fixes for the copypasta in debugfs
v4: bug in v3 (Daniel)
- if ((ring->id == RCS) && error->ccid)
+ if ((ring->id != RCS) || !error->ccid)
References: https://bugs.freedesktop.org/show_bug.cgi?id=55845
Reviewed-by (v2): Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
[danvet: Bikeshed away the redudant parenthese around ring->id != RCS]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
v2: Actually use num_pages (Chris)
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Caching the PIPESTAT enable bits has been deemed pointless. Just
read them from the register itself.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
The indentation is getting way too deep. Pull the vblank interupt
handling out to separate functions.
v2: Keep flip_mask handling in the main irq handler and
flatten {i8xx,i915}_handle_vblank() even further.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Use the gen3 logic for handling page flip interrupts on gen4.
Unfortuantely this kills the stall_check since that looks like it can
easily trigger too early. With the current logic the stall check would
kick in on the first vblank after the flip has been submitted to the
ring. If the CS takes longer than that to process the commands in the
ring, the stall check will cause the page flip to be complete too
early. That doesn't sound like a very good idea. Something better
should be deviced if we still need the stall check. For now, mark
i915_pageflip_stall_check() as unused.
v2: Fix irq enable_mask and add __always_unused (Chris Wilson)
References: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/1116587
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Tested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
If the interrupt handler were to process a previous vblank interrupt and
the following flip pending interrupt at the same time, the page flip
would be completed too soon.
To eliminate this race, check the live pending flip status from the ISR
register before finishing the page flip.
v2: Added a comment explaining the logic (by Chris Wilson)
v3: Fix a typo in the comment
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Tested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
GPU reset will drop all flips that are still in the ring. So after the
reset, call update_plane() for all CRTCs to make sure the primary
planes are scanning out from the correct buffer.
Also finish all pending flips. That means user space will get its
page flip events and won't get stuck waiting for them.
v2: Explicitly finish page flips instead of relying on FLIP_DONE
interrupt being generated by the base address update.
v3: Make two loops over crtcs to avoid deadlocks with the crtc mutex
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
[danvet: Fixup long line complaint from checkpatch.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
So we can remove duplicated code. Note that this function is used not
only on IBX, but also CPT and LPT.
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
[danvet: Also bikeshed s/ironlake_enable_pch_hotplug/ibx_enable_hotplug
to keep consistent with our ibx for pch naming scheme.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
They're physically the same pins and also the same bits, duplicating
only confuses the reader. This also makes it a bit obvious that we
have quite some code duplication going on here. Squashing that is for
a larger rework in our hpd handling though.
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This pulls in most of Linus tree up to -rc6, this fixes the worst lockdep
reported issues and re-enables fbcon lockdep.
(not the fbcon maintainer)
* 'fbcon-locking-fixes' of ssh://people.freedesktop.org/~airlied/linux: (529 commits)
Revert "Revert "console: implement lockdep support for console_lock""
fbcon: fix locking harder
fb: Yet another band-aid for fixing lockdep mess
fb: rework locking to fix lock ordering on takeover
/sys/kernel/debug has more or less been the standard location of debugfs
for several years now. Other parts of DRM already use this location, so
we should as well.
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Carl Worth <cworth@cworth.org>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
[danvet: split up long line.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Damien Lespiau wondered how race the gpu reset/hang detection code is
against concurrent gpu resets/hang detections or combinations thereof.
Luckily the single work item is guranteed to never run concurrently,
so reset handling is already single-threaded.
Hence we only have to worry about concurrent hang detections, or a
hang detection firing off while we're still processing an older gpu
reset request. Due to the new mechanism of setting the reset in
progress flag and the ordering guaranteed by the schedule_work
function there's nothing to do but add a comment explaining why we're
safe.
The only thing I've noticed is that we still try to reset the gpu now,
even when it is declared terminally wedged. Add a check for that to
avoid continous warnings about failed resets, in case the hangcheck
timer ever gets stuck.
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
With the previous patch the state transition handling of the reset
code itself is now (hopefully) race free and solid. But that still
leaves out everyone else - with the various lock-free wait paths
we have there's the possibility that the reset happens between the
point where we read the seqno we should wait on and the actual wait.
And if __wait_seqno then never sees the RESET_IN_PROGRESS state, we'll
happily wait for a seqno which will in all likelyhood never signal.
In practice this is not a big problem since the X server gets
constantly interrupted, and can then submit more work (hopefully) to
unblock everyone else: As soon as a new seqno write lands, all waiters
will unblock. But running the i-g-t reset testcase ZZ_hangman can
expose this race, especially on slower hw with fewer cpu cores.
Now looking forward to ARB_robustness and friends that's not the best
possible behaviour, hence this patch adds a reset_counter to be able
to detect any reset, even if a given thread never observed the
in-progress state.
The important part is to correctly order things:
- The write side needs to increment the counter after any seqno gets
reset. Hence we need to do that at the end of the reset work, and
again wake everyone up. We also need to place a barrier in between
any possible seqno changes and the counter increment, since any
unlock operations only guarantee that nothing leaks out, but not
that at later load operation gets moved ahead.
- On the read side we need to ensure that no reset can sneak in and
invalidate the seqno. In all cases we can use the one-sided barrier
that unlock operations guarantee (of the lock protecting the
respective seqno/ring pair) to ensure correct ordering. Hence it is
sufficient to place the atomic read before the mutex/spin_unlock and
no additional barriers are required.
The end-result of all this is that we need to wake up everyone twice
in a reset operation:
- First, before the reset starts, to get any lockholders of the locks,
so that the reset can proceed.
- Second, after the reset is completed, to allow waiters to properly
and reliably detect the reset condition and bail out.
I admit that this entire reset_counter thing smells a bit like
overkill, but I think it's justified since it makes it really explicit
what the bail-out condition is. And we need a reset counter anyway to
implement ARB_robustness, and imo with finer-grained locking on the
horizont this is the most resilient scheme I could think of.
v2: Drop spurious change in the wait_for_error EXIT_COND - we only
need to wait until we leave the reset-in-progress wedged state.
v3: Don't play tricks with barriers in the throttle ioctl, the
spin_unlock is barrier enough.
I've also considered using a little helper to grab the current
reset_counter, but then decided that hiding the atomic_read isn't a
great idea, since having it explicitly show up in the code is a nice
remainder to reviews to check the memory barriers.
v4: Add a comment to explain why we need to fall through in
__wait_seqno in the end variable assignments.
v5: Review from Damien:
- s/smb/smp/ in a comment
- don't increment the reset counter after we've set it to WEDGED. Now
we (again) properly wedge the gpu when the reset fails.
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
We have two important transitions of the wedged state in the current
code:
- 0 -> 1: This means a hang has been detected, and signals to everyone
that they please get of any locks, so that the reset work item can
do its job.
- 1 -> 0: The reset handler has completed.
Now the last transition mixes up two states: "Reset completed and
successful" and "Reset failed". To distinguish these two we do some
tricks with the reset completion, but I simply could not convince
myself that this doesn't race under odd circumstances.
Hence split this up, and add a new terminal state indicating that the
hw is gone for good.
Also add explicit #defines for both states, update comments.
v2: Split out the reset handling bugfix for the throttle ioctl.
v3: s/tmp/wedged/ sugested by Chris Wilson. Also fixup up a rebase
error which prevented this patch from actually compiling.
v4: To unify the wedged state with the reset counter, keep the
reset-in-progress state just as a flag. The terminally-wedged state is
now denoted with a big number.
v5: Add a comment to the reset_counter special values explaining that
WEDGED & RESET_IN_PROGRESS needs to be true for the code to be
correct.
v6: Fixup logic errors introduced with the wedged+reset_counter
unification. Since WEDGED implies reset-in-progress (in a way we're
terminally stuck in the dead-but-reset-not-completed state), we need
ensure that we check for this everywhere. The specific bug was in
wait_for_error, which would simply have timed out.
v7: Extract an inline i915_reset_in_progress helper to make the code
more readable. Also annote the reset-in-progress case with an
unlikely, to help the compiler optimize the fastpath. Do the same for
the terminally wedged case with i915_terminally_wedged.
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
And to make Ben Widawsky happier, use the gpu_error instead of
the entire device as the argument in some functions.
Drop the outdated comment on ->wedged for now, a follow-up patch will
change the semantics and add a proper comment again.
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This has been sprinkled all over the place in dev_priv. I think
it'd be good to also move all the code into a separate file like
i915_gem_error.c, but that's for another patch.
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
The purpose of the gtt structure is to help isolate our gtt specific
properties from the rest of the code (in doing so it help us finish the
isolation from the AGP connection).
The following members are pulled out (and renamed):
gtt_start
gtt_total
gtt_mappable_end
gtt_mappable
gtt_base_addr
gsm
The gtt structure will serve as a nice place to put gen specific gtt
routines in upcoming patches. As far as what else I feel belongs in this
structure: it is meant to encapsulate the GTT's physical properties.
This is why I've not added fields which track various drm_mm properties,
or things like gtt_mtrr (which is itself a pretty transient field).
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
[Ben modified commit messages]
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This variable is only used locally in the irq postinstall
functions for ivybridge and ironlake.
Signed-off-by: Egbert Eich <eich@suse.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Daniel writes:
- seqno wrap fixes and debug infrastructure from Mika Kuoppala and Chris
Wilson
- some leftover kill-agp on gen6+ patches from Ben
- hotplug improvements from Damien
- clear fb when allocated from stolen, avoids dirt on the fbcon (Chris)
- Stolen mem support from Chris Wilson, one of the many steps to get to
real fastboot support.
- Some DDI code cleanups from Paulo.
- Some refactorings around lvds and dp code.
- some random little bits&pieces
* tag 'drm-intel-next-2012-12-21' of git://people.freedesktop.org/~danvet/drm-intel: (93 commits)
drm/i915: Return the real error code from intel_set_mode()
drm/i915: Make GSM void
drm/i915: Move GSM mapping into dev_priv
drm/i915: Move even more gtt code to i915_gem_gtt
drm/i915: Make next_seqno debugs entry to use i915_gem_set_seqno
drm/i915: Introduce i915_gem_set_seqno()
drm/i915: Always clear semaphore mboxes on seqno wrap
drm/i915: Initialize hardware semaphore state on ring init
drm/i915: Introduce ring set_seqno
drm/i915: Missed conversion to gtt_pte_t
drm/i915: Bug on unsupported swizzled platforms
drm/i915: BUG() if fences are used on unsupported platform
drm/i915: fixup overlay stolen memory leak
drm/i915: clean up PIPECONF bpc #defines
drm/i915: add intel_dp_set_signal_levels
drm/i915: remove leftover display.update_wm assignment
drm/i915: check for the PCH when setting pch_transcoder
drm/i915: Clear the stolen fb before enabling
drm/i915: Access to snooped system memory through the GTT is incoherent
drm/i915: Remove stale comment about intel_dp_detect()
...
Conflicts:
drivers/gpu/drm/i915/intel_display.c
These are useful for investigating hangs involving WAIT_FOR_EVENT.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
[danvet: Apply a droplet of Future-Proof in the if-ladder.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Now that Chris Wilson demonstrated that the key for stability on early
gen 2 is to simple _never_ exchange the physical backing storage of
batch buffers I've tried a stab at a kernel solution. Doesn't look too
nefarious imho, now that I don't try to be too clever for my own good
any more.
v2: After discussing the various techniques, we've decided to always blit
batches on the suspect devices, but allow userspace to opt out of the
kernel workaround assume full responsibility for providing coherent
batches. The principal reason is that avoiding the blit does improve
performance in a few key microbenchmarks and also in cairo-trace
replays.
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
[danvet:
- Drop the hunk which uses HAS_BROKEN_CS_TLB to implement the ring
wrap w/a. Suggested by Chris Wilson.
- Also add the ACTHD check from Chris Wilson for the error state
dumping, so that we still catch batches when userspace opts out of
the w/a.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
For GMCH platforms we set up the hpd irq registers in the irq
postinstall hook. But since we only enable the irq sources we actually
need in PORT_HOTPLUG_EN/STATUS, taking dev_priv->hotplug_supported_mask
into account, no hpd interrupt sources is enabled since
commit 52d7ecedac
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Sat Dec 1 21:03:22 2012 +0100
drm/i915: reorder setup sequence to have irqs for output setup
Wrongly set-up interrupts also lead to broken hw-based load-detection
on at least GM45, resulting in ghost VGA/TV-out outputs.
To fix this, delay the hotplug register setup until after all outputs
are set up, by moving it into a new dev_priv->display.hpd_irq_callback.
We might also move the PCH_SPLIT platforms to such a setup eventually.
Another funny part is that we need to delay the fbdev initial config
probing until after the hpd regs are setup, for otherwise it'll detect
ghost outputs. But we can only enable the hpd interrupt handling
itself (and the output polling) _after_ that initial scan, due to
massive locking brain-damage in the fbdev setup code. Add a big
comment to explain this cute little dragon lair.
v2: Encapsulate all the fbdev handling by wrapping the move call into
intel_fbdev_initial_config in intel_fb.c. Requested by Chris Wilson.
v3: Applied bikeshed from Jesse Barnes.
v4: Imre Deak noticed that we also need to call intel_hpd_init after
the drm_irqinstall calls in the gpu reset and resume paths - otherwise
hotplug will be broken. Also improve the comment a bit about why
hpd_init needs to be called before we set up the initial fbdev config.
Bugzilla: Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=54943
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org> (v3)
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Commit 9ee32fea5f unconditionally prevents the CPU from entering idle states
until intel_dp_aux_ch completes for the first time, which never happens on my
DisplayPort-less intel gfx, causing the CPU to get rather hot.
Signed-off-by: Tomas Janousek <tomi@nomi.cz>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Before queuing the flip but crucially after attaching the unpin-work to
the crtc, we continue to setup the unpin-work. However, should the
hardware fire early, we see the connected unpin-work and queue the task.
The task then promptly runs and unpins the fb before we finish taking
the required references or even pinning it... Havoc.
To close the race, we use the flip-pending atomic to indicate when the
flip is finally setup and enqueued. So during the flip-done processing,
we can check more accurately whether the flip was expected.
v2: Add the appropriate mb() to ensure that the writes to the page-flip
worker are complete prior to marking it active and emitting the MI_FLIP.
On the read side, the mb should be enforced by the spinlocks.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@vger.kernel.org
[danvet: Review the barriers a bit, we need a write barrier both
before and after updating ->pending. Similarly we need a read barrier
in the interrupt handler both before and after reading ->pending. With
well-ordered irqs only one barrier in each place should be required,
but since this patch explicitly sets out to combat spurious interrupts
with is staged activation of the unpin work we need to go full-bore on
the barriers, too. Discussed with Chris Wilson on irc and changes
acked by him.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Having 9500 lines repeated on dmesg does not help me at all.
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
At least on the platforms that have a dp aux irq and also have it
enabled - vlvhsw should have one, too. But I don't have a machine to
test this on. Judging from docs there's no dp aux interrupt for gm45.
Also, I only have an ivb cpu edp machine, so the dp aux A code for
snb/ilk is untested.
For dpcd probing when nothing is connected it slashes about 5ms of cpu
time (cpu time is now negligible), which agrees with 3 * 5 400 usec
timeouts.
A previous version of this patch increases the time required to go
through the dp_detect cycle (which includes reading the edid) from
around 33 ms to around 40 ms. Experiments indicated that this is
purely due to the irq latency - the hw doesn't allow us to queue up
dp aux transactions and hence irq latency directly affects throughput.
gmbus is much better, there we have a 8 byte buffer, and we get the
irq once another 4 bytes can be queued up.
But by using the pm_qos interface to request the lowest possible cpu
wake-up latency this slowdown completely disappeared.
Since all our output detection logic is single-threaded with the
mode_config mutex right now anyway, I've decide not ot play fancy and
to just reuse the gmbus wait queue. But this would definitely prep the
way to run dp detection on different ports in parallel
v2: Add a timeout for dp aux transfers when using interrupts - the hw
_does_ prevent this with the hw-based 400 usec timeout, but if the
irq somehow doesn't arrive we're screwed. Lesson learned while
developing this ;-)
v3: While at it also convert the busy-loop to wait_for_atomic, so that
we don't run the risk of an infinite loop any more.
v4: Ensure we have the smallest possible irq latency by using the
pm_qos interface.
v5: Add a comment to the code to explain why we frob pm_qos. Suggested
by Chris Wilson.
v6: Disable dp irq for vlv, that's easier than trying to get at docs
and hw.
v7: Squash in a fix for Haswell that Paulo Zanoni tracked down - the
dp aux registers aren't at a fixed offset any more, but can be on the
PCH while the DP port is on the cpu die.
Reviewed-by: Imre Deak <imre.deak@intel.com> (v6)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Doesn't do anything yet than call dp_aux_irq_handler.
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
We need two special things to properly wire this up:
- Add another argument to gmbus_wait_hw_status to pass in the
correct interrupt bit in gmbus4.
- Since we can only get an irq for one of the two events we want,
hand-roll the wait_event_timeout code so that we wake up every
jiffie and can check for NAKs. This way we also subsume gmbus
support for platforms without interrupts (or where those are not
yet enabled).
The important bit really is to only enable one gmbus interrupt source
at the same time - with that piece of lore figured out, this seems to
work flawlessly.
Ben Widawsky rightfully complained the lack of measurements for the
claimed benefits (especially since the first version was actually
broken and fell back to bit-banging). Previously reading the 256 byte
hdmi EDID takes about 72 ms here. With this patch it's down to 33 ms.
Given that transfering the 256 bytes over i2c at wire speed takes
20.5ms alone, the reduction in additional overhead is rather nice.
v2: Chris Wilson wondered whether GMBUS4 might contain some set bits
when booting up an hence result in some spurious interrupts. Since we
clear GMBUS4 after every wait and we do gmbus transfer really early in
the setup sequence to detect displays the window is small, but still
be paranoid and clear it properly.
v3: Clarify the comment that gmbus irq generation can only support one
kind of event, why it bothers us and how we work around that limit.
Cc: Daniel Kurtz <djkurtz@chromium.org>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Egbert Eich