Hugh Dickins found that characters in xterm were going missing and oft
delayed. Being the curious type, he managed to associate this with the
new high-precision vblank patches; disabling these he found, restored
the orderliness of his characters.
The oddness begins when one realised that Hugh was not using vblanks at
all on his system (fvwm and some xterms). Instead, all he had to go on
were warning of a pipe underrun, curiously enough at around 60Hz. He
poked and found that in addition to the underrun warning, the hardware
was flagging the start of a new frame, a vblank, which in turn was
kicking off the pending vblank processing code.
There is little we can do for the underruns on Hugh's machine, a
Crestline [965GM], which must have its FIFO watermarks set to 8.
However, we do not need to process the vblank if we know that they are
disabled...
Reported-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
* 'intel/drm-intel-next' of /ssd/git/drm-next: (771 commits)
drm/i915: Undo "Uncouple render/power ctx before suspending"
drm/i915: Allow the application to choose the constant addressing mode
drm/i915: dynamic render p-state support for Sandy Bridge
drm/i915: Enable EI mode for RCx decision making on Sandybridge
drm/i915/sdvo: Border and stall select became test bits in gen5
drm/i915: Add Guess-o-matic for pageflip timestamping.
drm/i915: Add support for precise vblank timestamping (v2)
drm/i915: Add frame buffer compression on Sandybridge
drm/i915: Add self-refresh support on Sandybridge
drm/i915: Wait for vblank before unpinning old fb
Revert "drm/i915: Avoid using PIPE_CONTROL on Ironlake"
drm/i915: Pass clock limits down to PLL matcher
drm/i915: Poll for seqno completion if IRQ is disabled
drm/i915/ringbuffer: Make IRQ refcnting atomic
agp/intel: Fix missed cached memory flags setting in i965_write_entry()
drm/i915/sdvo: Only use the SDVO pin if it is in the valid range
drm/i915: Enable RC6 autodownclocking on Sandybridge
drm/i915: Terminate the FORCE WAKE after we have finished reading
drm/i915/gtt: Clear the cachelines upon resume
drm/i915: Restore GTT mapping first upon resume
...
This patch tries to make sure that the vbl.reply.sequence
vblank count for a queued or emitted vblank event always
corresponds to the true vblank count of queueing/emission, so
the ddx can rely on the returned target_msc for consistency
checks and implementation of swap_intervals in glXSwapBuffers().
Without this there is a small race-condition between the
userspace ddx queueing a vblank event and the vblank
counter incrementing before the event gets queued in
the kernel.
Signed-off-by: Mario Kleiner <mario.kleiner@tuebingen.mpg.de>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
The "e" pointer is either NULL or freed when we call
drm_vblank_put(dev, e->pipe) on the error path. Just pass the "pipe"
variable directly instead.
I changed another caller to use "pipe" as well for consistency.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Kristian Høgsberg <krh@bitplanet.net>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
The DRI2 swap & sync implementation needs precise
vblank counts and precise timestamps corresponding
to those vblank counts. For conformance to the OpenML
OML_sync_control extension specification the DRM
timestamp associated with a vblank count should
correspond to the start of video scanout of the first
scanline of the video frame following the vblank
interval for that vblank count.
Therefore we need to carry around precise timestamps
for vblanks. Currently the DRM and KMS drivers generate
timestamps ad-hoc via do_gettimeofday() in some
places. The resulting timestamps are sometimes not
very precise due to interrupt handling delays, they
don't conform to OML_sync_control and some are wrong,
as they aren't taken synchronized to the vblank.
This patch implements support inside the drm core
for precise and robust timestamping. It consists
of the following interrelated pieces.
1. Vblank timestamp caching:
A per-crtc ringbuffer stores the most recent vblank
timestamps corresponding to vblank counts.
The ringbuffer can be read out lock-free via the
accessor function:
struct timeval timestamp;
vblankcount = drm_vblank_count_and_time(dev, crtcid, ×tamp).
The function returns the current vblank count and
the corresponding timestamp for start of video
scanout following the vblank interval. It can be
used anywhere between enclosing drm_vblank_get(dev, crtcid)
and drm_vblank_put(dev,crtcid) statements. It is used
inside the drmWaitVblank ioctl and in the vblank event
queueing and handling. It should be used by kms drivers for
timestamping of bufferswap completion.
The timestamp ringbuffer is reinitialized each time
vblank irq's get reenabled in drm_vblank_get()/
drm_update_vblank_count(). It is invalidated when
vblank irq's get disabled.
The ringbuffer is updated inside drm_handle_vblank()
at each vblank irq.
2. Calculation of precise vblank timestamps:
drm_get_last_vbltimestamp() is used to compute the
timestamp for the end of the most recent vblank (if
inside active scanout), or the expected end of the
current vblank interval (if called inside a vblank
interval). The function calls into a new optional kms
driver entry point dev->driver->get_vblank_timestamp()
which is supposed to provide the precise timestamp.
If a kms driver doesn't implement the entry point or
if the call fails, a simple do_gettimeofday() timestamp
is returned as crude approximation of the true vblank time.
A new drm module parameter drm.timestamp_precision_usec
allows to disable high precision timestamps (if set to
zero) or to specify the maximum acceptable error in
the timestamps in microseconds.
Kms drivers could implement their get_vblank_timestamp()
function in a gpu specific way, as long as returned
timestamps conform to OML_sync_control, e.g., by use
of gpu specific hardware timestamps.
Optionally, kms drivers can simply wrap and use the new
utility function drm_calc_vbltimestamp_from_scanoutpos().
This function calls a new optional kms driver function
dev->driver->get_scanout_position() which returns the
current horizontal and vertical video scanout position
of the crtc. The scanout position together with the
drm_display_timing of the current video mode is used
to calculate elapsed time relative to start of active scanout
for the current video frame. This elapsed time is subtracted
from the current do_gettimeofday() time to get the timestamp
corresponding to start of video scanout. Currently
non-interlaced, non-doublescan video modes, with or
without panel scaling are handled correctly. Interlaced/
doublescan modes are tbd in a future patch.
3. Filtering of redundant vblank irq's and removal of
some race-conditions in the vblank irq enable/disable path:
Some gpu's (e.g., Radeon R500/R600) send spurious vblank
irq's outside the vblank if vblank irq's get reenabled.
These get detected by use of the vblank timestamps and
filtered out to avoid miscounting of vblanks.
Some race-conditions between the vblank irq enable/disable
functions, the vblank irq handler and the gpu itself (updating
its hardware vblank counter in the "wrong" moment) are
fixed inside vblank_disable_and_save() and
drm_update_vblank_count() by use of the vblank timestamps and
a new spinlock dev->vblank_time_lock.
The time until vblank irq disable is now configurable via
a new drm module parameter drm.vblankoffdelay to allow
experimentation with timeouts that are much shorter than
the current 5 seconds and should allow longer vblank off
periods for better power savings.
Followup patches will use these new functions to
implement precise timestamping for the intel and radeon
kms drivers.
Signed-off-by: Mario Kleiner <mario.kleiner@tuebingen.mpg.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Allows us to track each process that requests and completes events.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Emit a trace point for vblank events. This can be helpful for mapping
drawing activity against the vblank frequency and period.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Allow platform devices without PCI resources to be DRM devices.
[airlied: fixup warnings with dev pointers]
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
* 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6:
drm/radeon: Fix sparc regression in r300_scratch()
drm: make sure vblank interrupts are disabled at DPMS time
drm/radeon/kms/evergreen: No EnableYUV table
drm/radeon: 9800 SE has only one quadpipe
drm/radeon/kms: don't print error for legal crtcs.
drm/radeon/kms/evergreen: fix LUT setup
When we call drm_vblank_off() at DPMS off time (to wake any clients so
they don't hang) we need to make sure interrupts are actually disabled.
If drm_vblank_off() gets called before the vblank usage timer expires,
it'll prevent the timer from disabling interrupts since it also clears
the vblank_enabled flag for the pipe.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
In some case vblank might not be initialized and we shouldn't
try to use associated function. This patch make sure this is
the case. It also export drm_vblank_cleanup so driver can cleanup
vblank if for any reason IRQ/MSI is not working.
Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
In current vblank-wait implementation, if we turn off VGA output,
drm_wait_vblank will still wait on the disabled pipe until timeout,
because vblank on the pipe is assumed be enabled. This would cause
slow system response on some system such as moblin.
This patch resolve the issue by adding a drm helper function
drm_vblank_off which explicitly clear vblank_enabled[crtc], wake up
any waiting queue and save last vblank counter before turning off
crtc. It also slightly change drm_vblank_get to ensure that we will
will return immediately if trying to wait on a disabled pipe.
Signed-off-by: Li Peng <peng.li@intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
[anholt: hand-applied for conflicts with overlay changes]
Signed-off-by: Eric Anholt <eric@anholt.net>
If we queue a vblank event but miss it, we should return the actual
sequence number we queued to userspace, so its event handling function
will know which event to look for.
Acked-by: Kristian Høgsberg <krh@bitplanet.net>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This patch adds a new flag to the drmWaitVblank ioctl, which asks the drm
to return immediately and notify userspace when the specified vblank sequence
happens by sending an event back on the drm fd.
The event mechanism works with the other flags supported by the ioctls,
specifically, the vblank sequence can be specified relatively or absolutely,
and works for primary and seconday crtc.
The signal field of the vblank request is used to provide user data,
which will be sent back to user space in the vblank event.
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
VGA arb requires DRM support for non-kms drivers, to turn on/off
irqs when disabling the mem/io regions.
VGA arb requires KMS support for GPUs where we can turn off VGA
decoding. Currently we know how to do this for intel and radeon
kms drivers, which allows them to be removed from the arbiter.
This patch comes from Fedora rawhide kernel.
Signed-off-by: Dave Airlie <airlied@redhat.com>
Some applications/hardware combinations are triggering the message "failed to
acquire vblank counter" to be issued up to 20 times a second, which makes it
both useless and dangerous, as this may hide other important messages.
This changes makes it only appear when people are debugging.
Signed-off-by: Paul Rolland <rol@as2917.net>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Lost-twice-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
It hasn't been used in ages, and having the user tell your how much
memory is being freed at free time is a recipe for disaster even if it
was ever used.
Signed-off-by: Eric Anholt <eric@anholt.net>
allocating devname in the i915 driver was a hack originally and I
forgot to figure out how to do this properly back then.
So this is the cleaner version that just picks devname or driver name
in the irq code.
It removes the devname allocs from the i915 driver.
Signed-off-by: Dave Airlie <airlied@redhat.com>
The first time we install a mode, the vblank will be disabled for a pipe
and so drm_vblank_get() in drm_vblank_pre_modeset() will fail. As we
unconditionally call drm_vblank_put() afterwards, the vblank reference
counter becomes unbalanced.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Dave Airlie <airlied@linux.ie>
In dc1336ff4f (set vblank enable flag correctly
across IRQ uninstall), we made sure drivers that uninstall their interrupt
handler set the vblank enabled flag correctly, so that when interrupts are
re-enabled, vblank interrupts & counts work as expected. However I missed the
last_vblank field: it needs to be updated as well, otherwise, at the next
drm_update_vblank_count we'll end up comparing a current count to a stale
one (the last one captured by the disable function), which may trigger the
wraparound handling, leading to a jumpy counter and hangs in drm_wait_vblank.
The jumpy counter can prevent the DRM_WAIT_ON from returning success if the
difference between the current count and the requested count is greater than
2^23, leading to timeouts or hangs, if the ioctl is restarted in a loop (as
is the case in libdrm < 2.4.4).
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Acked-by: Michel Dänzer <michel@daenzer.net>
Tested-by: Timo Aaltonen <tjaalton@cc.hut.fi>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Schedule a vblank signal, kill the process, and we'll go walking over freed
memory. Given that no open-source userland exists using this, nor have I
ever heard of a consumer, just let this code die.
Signed-off-by: Eric Anholt <eric@anholt.net>
Requested-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Dave Airlie <airlied@linux.ie>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In the absence of kernel mode setting, many drivers disable IRQs across VT
switch. The core DRM vblank code is missing a check for this case however;
even after IRQ disable, the vblank code will still have the vblank_enabled
flag set, so unless we track the fact that they're disabled at IRQ uninstall
time, when we VT switch back in we won't actually re-enable them, which means
any apps waiting on vblank before the switch will hang.
This patch does that and also adds a sanity check to the wait condition to
look for the irq_enabled flag in general, as well as adding a wakeup to the
IRQ uninstall path.
Fixes fdo bug #18879 with compiz hangs at VT switch.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@linux.ie>
Add mode setting support to the DRM layer.
This is a fairly big chunk of work that allows DRM drivers to provide
full output control and configuration capabilities to userspace. It was
motivated by several factors:
- the fb layer's APIs aren't suited for anything but simple
configurations
- coordination between the fb layer, DRM layer, and various userspace
drivers is poor to non-existent (radeonfb excepted)
- user level mode setting drivers makes displaying panic & oops
messages more difficult
- suspend/resume of graphics state is possible in many more
configurations with kernel level support
This commit just adds the core DRM part of the mode setting APIs.
Driver specific commits using these new structure and APIs will follow.
Co-authors: Jesse Barnes <jbarnes@virtuousgeek.org>, Jakob Bornecrantz <jakob@tungstengraphics.com>
Contributors: Alan Hourihane <alanh@tungstengraphics.com>, Maarten Maathuis <madman2003@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
drm vblank initialization keeps track of the changes in driver-supplied
frame counts across vt switch and mode setting, but only if you let it by
not tearing down the drm vblank structure.
Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
It's not used in any other drivers, and doesn't look like it will be from
drm.git master.
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@linux.ie>
If the failing paths were hit, the vblank IRQ would never get turned off
again.
Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Like the last patch but adds a macro to get at the irq value instead of
dereferencing pdev directly. Should make things easier for the BSD guys and
if we ever support non-PCI devices.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Previously, drivers supporting vblank interrupt waits would run the interrupt
all the time, or all the time that any 3d client was running, preventing the
CPU from sleeping for long when the system was otherwise idle. Now, interrupts
are disabled any time that no client is waiting on a vblank event. The new
method uses vblank counters on the chipsets when the interrupts are turned
off, rather than counting interrupts, so that we can continue to present
accurate vblank numbers.
Co-author: Michel Dänzer <michel@tungstengraphics.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Previous attempts at interrupt mitigation had been foiled by i915_wait_irq's
failure to update the sarea seqno value when the status page indicated that
the seqno had already been passed. MSI support has been seen to cut CPU
costs by up to 40% in some workloads by avoiding other expensive interrupt
handlers for frequent graphics interrupts.
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
If a specific tasklet shares data with irq context,
it needs to take a private irq-blocking spinlock within
the tasklet itself.
Signed-off-by: Dave Airlie <airlied@redhat.com>
With the coming of kernel based modesetting and the memory manager stuff,
the everything in one directory approach was getting very ugly and
starting to be unmanageable.
This restructures the drm along the lines of other kernel components.
It creates a drivers/gpu/drm directory and moves the hw drivers into
subdirectores. It moves the includes into an include/drm, and
sets up the unifdef for the userspace headers we should be exporting.
Signed-off-by: Dave Airlie <airlied@redhat.com>
Chris Wilson