This effectively reverts
commit 489375c866
Author: Imre Deak <imre.deak@intel.com>
Date: Mon Oct 24 19:33:31 2016 +0300
drm/i915/lspcon: Add workaround for resuming in PCON mode
The workaround was added without considering that HPD is low during
the failed AUX transfers the WA fixed. Since the previous patch we
wait for HPD to get asserted. My tests also show that this happens
_after_ the DPCD reads start to return correct values. This
suggests that we don't need this WA any more, let's try to remove
it to reduce the clutter.
Cc: Shashank Sharma <shashank.sharma@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Shashank Sharma <shashank.sharma@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1485509961-9010-4-git-send-email-imre.deak@intel.com
During system resume time initialization the HPD level on LSPCON ports
can stay low for an extended amount of time, leading to failed AUX
transfers and LSPCON initialization. Fix this by waiting for HPD to get
asserted.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99178
Cc: Shashank Sharma <shashank.sharma@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: <stable@vger.kernel.org> # v4.9+
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Shashank Sharma <shashank.sharma@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1485509961-9010-3-git-send-email-imre.deak@intel.com
All callers asked for a forced change but the function ignored this
parameter. It doesn't seem to be necessary to force the change in any
case so let's just remove the parameter.
Cc: Shashank Sharma <shashank.sharma@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Shashank Sharma <shashank.sharma@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1479755707-29596-5-git-send-email-imre.deak@intel.com
Some LSPCON adaptors may return an incorrect LSPCON mode right after
waking from DP Sleep state. This is the case at least for the ParadTech
PS175 adaptor, both when waking because of exiting the DP Sleep to
active state, or due to any other AUX CH transfer. We can determine the
current expected mode based on whether the DPCD area is accessible,
since according to the LSPCON spec this area is only accesible
in PCON mode.
This wait will avoid us trying to change the mode, while the current
expected mode hasn't settled yet and start link training before the
adaptor thinks it's in PCON mode after waking from DP Sleep state.
Cc: Shashank Sharma <shashank.sharma@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Shashank Sharma <shashank.sharma@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1479755707-29596-4-git-send-email-imre.deak@intel.com
Some LSPCON adaptors won't properly wake up in response to an AUX
request after the adaptor was placed to a DP Sink Sleep state (via
writing 0x2 to DP_SET_POWER). Based on the DP 1.4 specification 5.2.5,
the sink may place the AUX CH into a low-power state while in Sleep
state, but should wake it up in response to an AUX request within 1-20ms
(answering with AUX defers while waking it up). As opposed to this at
least the ParadTech PS175 adaptor won't fully wake in response to the
first I2C-over-AUX access and will occasionally ignore the offset in I2C
messages. This can result in accessing the DDC register at offset 0
regardless of the specified offset and the LSPCON detection failing.
To fix this do an initial dummy read from the DPCD area. The PS175 will
defer this access until it's fully woken (taking ~150ms) making sure the
following I2C-over-AUX accesses will work correctly.
Cc: Shashank Sharma <shashank.sharma@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Reference: https://bugs.freedesktop.org/show_bug.cgi?id=98353
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Shashank Sharma <shashank.sharma@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1479755707-29596-2-git-send-email-imre.deak@intel.com
On my APL the LSPCON firmware resumes in PCON mode as opposed to the
expected LS mode. It also appears to be in a state where AUX DPCD reads
will succeed but return garbage recovering only after a few hundreds of
milliseconds. After the recovery time DPCD reads will result in the
correct values and things will continue to work. If I2C over AUX is
attempted during this recovery time (implying an AUX write transaction)
the firmware won't recover and will stay in this broken state.
As a workaround check if the firmware is in PCON state after resume and
if so wait until the correct DPCD values are returned. For this we
compare the branch descriptor with the one we cached during init time.
If the firmware was in the LS state, we skip the w/a and continue as
before.
v2:
- Use the DP descriptor value cached in intel_dp. (Jani)
- Get to intel_dp using container_of(), instead of a cached ptr.
(Shashank)
- Use usleep_range() instead of msleep().
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98353
Cc: Shashank Sharma <shashank.sharma@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477326811-30431-9-git-send-email-imre.deak@intel.com
We can use the container_of() magic to get to the DDC adapter, so no
need for caching a pointer to it. We'll also need to get at the intel_dp
ptr in the following patch, so add a helper that can be used for both
purposes.
Cc: Shashank Sharma <shashank.sharma@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477326811-30431-8-git-send-email-imre.deak@intel.com
As for external DP sink and branch devices read and print the DP
descriptor for eDP and LSPCON devices as well to aid debugging.
v2:
- Split out this change to a separate patch. (Jani)
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477326811-30431-7-git-send-email-imre.deak@intel.com
All types of DP devices (eDP, DP sink, DP branch) will fail their probe
if the start of DPCD can't be read. The LSPCON PCON functionality also
depends on accessing this area, so fail the probe if the read fails.
Cc: Shashank Sharma <shashank.sharma@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477326811-30431-6-git-send-email-imre.deak@intel.com
Fixes sparse warning:
drivers/gpu/drm/i915/intel_lspcon.c:30:22: warning: symbol
'lspcon_get_current_mode' was not declared. Should it be static?
Fixes: dbe9e61b8e ("drm/i915: Add lspcon support for I915 driver")
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Shashank Sharma <shashank.sharma@intel.com>
Reviewed-by: Shashank Sharma <shashank.sharma@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1476789711-19697-2-git-send-email-jani.nikula@intel.com
As per the software design, we are driving lspcon in
PCON mode. But while resuming from suspend, lspcon can go
in LS mode (which is its default operating mode on power on)
This patch adds a resume function for lspcon, which makes sure
its operating in PCON mode, post resume.
V2: Address review comments from Imre
- move lspcon_resume call to encoder->reset()
- use early returns
Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1476455212-27893-6-git-send-email-shashank.sharma@intel.com
This patch adds a new file, to accommodate lspcon support
for I915 driver. These functions probe, detect, initialize
and configure an on-board lspcon device during the driver
init time.
Also, this patch adds a small structure for lspcon device,
which will provide the runtime status of the device.
V2: addressed ville's review comments
- Clean the leftover macros from previous patch set
V3: Rebase
V4: addressed ville's review comments
- make internal functions static
- remove lspcon_detect_identifier, make it inline with lspcon_probe
- remove is_lspcon_active function
- remove force check while setting a lspcon mode
V5: Rebase
V6: Pass dev_priv to IS_GEN9 check
Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
Signed-off-by: Akashdeep Sharma <akashdeep.sharma@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1476455212-27893-3-git-send-email-shashank.sharma@intel.com
Imre Deak