[4.4-rc1][Regression] drm/i915: Check live status before reading edid

[4.4-rc1][Regression] drm/i915: Check live status before reading edid

[Joseph Salisbury]

Hi Sonika,

A kernel bug report was opened against Ubuntu [0].  After a kernel
bisect, it was found that reverting the following commit resolved this bug:

commit 237ed86c693d8a8e4db476976aeb30df4deac74b
Author: Sonika Jindal <sonika.jindal@intel.com>
Date:   Tue Sep 15 09:44:20 2015 +0530

    drm/i915: Check live status before reading edid



The regression was introduced as of v4.4-rc1.

I was hoping to get your feedback, since you are the patch author.  Do
think increasing the number of tries in intel_hdmi_detect() is worth
trying?  Do you think gathering any additional data will help diagnose
this issue, or would it be best to submit a revert request?
    

Thanks,
    
Joe

[0] http://pad.lv/lp1543683

RE: [4.4-rc1][Regression] drm/i915: Check live status before reading edid

[Jindal, Sonika]

Hi Joe,

Yes, first thing to try is to increase the tries.
Can you please point me to the bug and provide more details like platform, monitor, cable.
Are you referring to the same issue as Oleksandr reported where a single link dvi/hdmi cable didn’t work and dual link worked?

Regards,
Sonika

-----Original Message-----
From: Joseph Salisbury [mailto:joseph.salisbury@canonical.com] 
Sent: Thursday, February 25, 2016 3:09 AM
To: Jindal, Sonika <sonika.jindal@intel.com>
Cc: Sharma, Shashank <shashank.sharma@intel.com>; Vivi, Rodrigo <rodrigo.vivi@intel.com>; Daniel Vetter <daniel.vetter@ffwll.ch>; Jani Nikula <jani.nikula@linux.intel.com>; David Airlie <airlied@linux.ie>; intel-gfx <intel-gfx@lists.freedesktop.org>; dri-devel <dri-devel@lists.freedesktop.org>; LKML <linux-kernel@vger.kernel.org>
Subject: [4.4-rc1][Regression] drm/i915: Check live status before reading edid

Hi Sonika,

A kernel bug report was opened against Ubuntu [0].  After a kernel bisect, it was found that reverting the following commit resolved this bug:

commit 237ed86c693d8a8e4db476976aeb30df4deac74b
Author: Sonika Jindal <sonika.jindal@intel.com>
Date:   Tue Sep 15 09:44:20 2015 +0530

    drm/i915: Check live status before reading edid



The regression was introduced as of v4.4-rc1.

I was hoping to get your feedback, since you are the patch author.  Do think increasing the number of tries in intel_hdmi_detect() is worth trying?  Do you think gathering any additional data will help diagnose this issue, or would it be best to submit a revert request?
    

Thanks,
    
Joe

[0] http://pad.lv/lp1543683

Re: [4.4-rc1][Regression] drm/i915: Check live status before reading edid

[Joseph Salisbury]

On 02/24/2016 10:53 PM, Jindal, Sonika wrote:
> Hi Joe,
>
> Yes, first thing to try is to increase the tries.
We testing with 300 retries, but the second monitor still did not show
up.  However, it did show up in lspci.


> Can you please point me to the bug and provide more details like platform, monitor, cable.
The bug is at: http://pad.lv/1543683 .  All the hardware details should
be in the bug report.  The cable is a single link dvi-d cable. 
Unfortunately the bug reporter does not have a dual link cable to test.
If you need any additional info, we can ask the bug reporter.
> Are you referring to the same issue as Oleksandr reported where a single link dvi/hdmi cable didn’t work and dual link worked?
I'm not sure if this is the exact issue or not.  I'll review the other
thread and compare.

>
> Regards,
> Sonika
>
> -----Original Message-----
> From: Joseph Salisbury [mailto:joseph.salisbury@canonical.com] 
> Sent: Thursday, February 25, 2016 3:09 AM
> To: Jindal, Sonika <sonika.jindal@intel.com>
> Cc: Sharma, Shashank <shashank.sharma@intel.com>; Vivi, Rodrigo <rodrigo.vivi@intel.com>; Daniel Vetter <daniel.vetter@ffwll.ch>; Jani Nikula <jani.nikula@linux.intel.com>; David Airlie <airlied@linux.ie>; intel-gfx <intel-gfx@lists.freedesktop.org>; dri-devel <dri-devel@lists.freedesktop.org>; LKML <linux-kernel@vger.kernel.org>
> Subject: [4.4-rc1][Regression] drm/i915: Check live status before reading edid
>
> Hi Sonika,
>
> A kernel bug report was opened against Ubuntu [0].  After a kernel bisect, it was found that reverting the following commit resolved this bug:
>
> commit 237ed86c693d8a8e4db476976aeb30df4deac74b
> Author: Sonika Jindal <sonika.jindal@intel.com>
> Date:   Tue Sep 15 09:44:20 2015 +0530
>
>     drm/i915: Check live status before reading edid
>
>
>
> The regression was introduced as of v4.4-rc1.
>
> I was hoping to get your feedback, since you are the patch author.  Do think increasing the number of tries in intel_hdmi_detect() is worth trying?  Do you think gathering any additional data will help diagnose this issue, or would it be best to submit a revert request?
>     
>
> Thanks,
>     
> Joe
>
> [0] http://pad.lv/lp1543683
>

Re: [4.4-rc1][Regression] drm/i915: Check live status before reading edid

[Jindal, Sonika]

On 2/26/2016 12:11 AM, Joseph Salisbury wrote:
> On 02/24/2016 10:53 PM, Jindal, Sonika wrote:
>> Hi Joe,
>>
>> Yes, first thing to try is to increase the tries.
> We testing with 300 retries, but the second monitor still did not show
> up.  However, it did show up in lspci.
>
>
>> Can you please point me to the bug and provide more details like platform, monitor, cable.
> The bug is at: http://pad.lv/1543683 .  All the hardware details should
> be in the bug report.  The cable is a single link dvi-d cable.
> Unfortunately the bug reporter does not have a dual link cable to test.
> If you need any additional info, we can ask the bug reporter.
If this is with single link cable, the issue could be the same.
As Ville suggested for the other issue to use video=HDMI-A-1:e as 
command line argument, can you please give it a try?
The logs shared in the bug doesn't have drm logs enabled, so couldnt get 
much out of it.
Which platform is this?

Alternatively you can add something like following in intel_hdmi_detect 
to make it ignore the live status checks.

@@ -1419,7 +1419,7 @@ intel_hdmi_detect(struct drm_connector *connector, 
bool force)

         intel_hdmi_unset_edid(connector);
-
+       live_status = live_status | force;
         if (intel_hdmi_set_edid(connector, live_status)) {
                 struct intel_hdmi *intel_hdmi = 
intel_attached_hdmi(connector);


Regards,
Sonika
>> Are you referring to the same issue as Oleksandr reported where a single link dvi/hdmi cable didn’t work and dual link worked?
> I'm not sure if this is the exact issue or not.  I'll review the other
> thread and compare.
>
>> Regards,
>> Sonika
>>
>> -----Original Message-----
>> From: Joseph Salisbury [mailto:joseph.salisbury@canonical.com]
>> Sent: Thursday, February 25, 2016 3:09 AM
>> To: Jindal, Sonika <sonika.jindal@intel.com>
>> Cc: Sharma, Shashank <shashank.sharma@intel.com>; Vivi, Rodrigo <rodrigo.vivi@intel.com>; Daniel Vetter <daniel.vetter@ffwll.ch>; Jani Nikula <jani.nikula@linux.intel.com>; David Airlie <airlied@linux.ie>; intel-gfx <intel-gfx@lists.freedesktop.org>; dri-devel <dri-devel@lists.freedesktop.org>; LKML <linux-kernel@vger.kernel.org>
>> Subject: [4.4-rc1][Regression] drm/i915: Check live status before reading edid
>>
>> Hi Sonika,
>>
>> A kernel bug report was opened against Ubuntu [0].  After a kernel bisect, it was found that reverting the following commit resolved this bug:
>>
>> commit 237ed86c693d8a8e4db476976aeb30df4deac74b
>> Author: Sonika Jindal <sonika.jindal@intel.com>
>> Date:   Tue Sep 15 09:44:20 2015 +0530
>>
>>      drm/i915: Check live status before reading edid
>>
>>
>>
>> The regression was introduced as of v4.4-rc1.
>>
>> I was hoping to get your feedback, since you are the patch author.  Do think increasing the number of tries in intel_hdmi_detect() is worth trying?  Do you think gathering any additional data will help diagnose this issue, or would it be best to submit a revert request?
>>      
>>
>> Thanks,
>>      
>> Joe
>>
>> [0] http://pad.lv/lp1543683
>>
>

Re: [4.4-rc1][Regression] drm/i915: Check live status before reading edid

[Jani Nikula]

On Wed, 24 Feb 2016, Joseph Salisbury <joseph.salisbury@canonical.com> wrote:
> Hi Sonika,
>
> A kernel bug report was opened against Ubuntu [0].  After a kernel
> bisect, it was found that reverting the following commit resolved this bug:
>
> commit 237ed86c693d8a8e4db476976aeb30df4deac74b
> Author: Sonika Jindal <sonika.jindal@intel.com>
> Date:   Tue Sep 15 09:44:20 2015 +0530
>
>     drm/i915: Check live status before reading edid
>
>
>
> The regression was introduced as of v4.4-rc1.
>
> I was hoping to get your feedback, since you are the patch author.  Do
> think increasing the number of tries in intel_hdmi_detect() is worth
> trying?  Do you think gathering any additional data will help diagnose
> this issue, or would it be best to submit a revert request?

There are at least the following commits claiming to fix issues in the
above commit. Please make sure you have them.

BR,
Jani.


commit 8d409cb3e8a24196be7271defafd4638f3e0b514
Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
Date:   Wed Feb 10 19:59:05 2016 +0200

    drm/i915: Fix hpd live status bits for g4x

commit 3d8acd1f667b45c531401c8f0c2033072e32a05d
Author: Gary Wang <gary.c.wang@intel.com>
Date:   Wed Dec 23 16:11:35 2015 +0800

    drm/i915: increase the tries for HDMI hotplug live status checking

commit 97f9010af05c15e0b7e6b4ef6ff8cb0ebb7e7715
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Fri Dec 11 19:44:15 2015 +0100

    drm/i915: mdelay(10) considered harmful

commit 0f5a9be15797f78c9a34e432f26c796165b6e49a
Author: Imre Deak <imre.deak@intel.com>
Date:   Fri Nov 27 18:55:29 2015 +0200

    drm/i915: take a power domain reference while checking the HDMI live status




-- 
Jani Nikula, Intel Open Source Technology Center

Re: [4.4-rc1][Regression] drm/i915: Check live status before reading edid

[Joseph Salisbury]

On 02/29/2016 04:33 AM, Jani Nikula wrote:
> On Wed, 24 Feb 2016, Joseph Salisbury <joseph.salisbury@canonical.com> wrote:
>> Hi Sonika,
>>
>> A kernel bug report was opened against Ubuntu [0].  After a kernel
>> bisect, it was found that reverting the following commit resolved this bug:
>>
>> commit 237ed86c693d8a8e4db476976aeb30df4deac74b
>> Author: Sonika Jindal <sonika.jindal@intel.com>
>> Date:   Tue Sep 15 09:44:20 2015 +0530
>>
>>     drm/i915: Check live status before reading edid
>>
>>
>>
>> The regression was introduced as of v4.4-rc1.
>>
>> I was hoping to get your feedback, since you are the patch author.  Do
>> think increasing the number of tries in intel_hdmi_detect() is worth
>> trying?  Do you think gathering any additional data will help diagnose
>> this issue, or would it be best to submit a revert request?
Thanks for the info.  I will have all of these commits tested.


> There are at least the following commits claiming to fix issues in the
> above commit. Please make sure you have them.
>
> BR,
> Jani.
>
>
> commit 8d409cb3e8a24196be7271defafd4638f3e0b514
> Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Date:   Wed Feb 10 19:59:05 2016 +0200
>
>     drm/i915: Fix hpd live status bits for g4x
>
> commit 3d8acd1f667b45c531401c8f0c2033072e32a05d
> Author: Gary Wang <gary.c.wang@intel.com>
> Date:   Wed Dec 23 16:11:35 2015 +0800
>
>     drm/i915: increase the tries for HDMI hotplug live status checking
>
> commit 97f9010af05c15e0b7e6b4ef6ff8cb0ebb7e7715
> Author: Daniel Vetter <daniel.vetter@ffwll.ch>
> Date:   Fri Dec 11 19:44:15 2015 +0100
>
>     drm/i915: mdelay(10) considered harmful
>
> commit 0f5a9be15797f78c9a34e432f26c796165b6e49a
> Author: Imre Deak <imre.deak@intel.com>
> Date:   Fri Nov 27 18:55:29 2015 +0200
>
>     drm/i915: take a power domain reference while checking the HDMI live status
>
>
>
>

Re: [4.4-rc1][Regression] drm/i915: Check live status before reading edid

[Joseph Salisbury]

On 03/02/2016 04:58 PM, Joseph Salisbury wrote:
> On 02/29/2016 04:33 AM, Jani Nikula wrote:
>> On Wed, 24 Feb 2016, Joseph Salisbury <joseph.salisbury@canonical.com> wrote:
>>> Hi Sonika,
>>>
>>> A kernel bug report was opened against Ubuntu [0].  After a kernel
>>> bisect, it was found that reverting the following commit resolved this bug:
>>>
>>> commit 237ed86c693d8a8e4db476976aeb30df4deac74b
>>> Author: Sonika Jindal <sonika.jindal@intel.com>
>>> Date:   Tue Sep 15 09:44:20 2015 +0530
>>>
>>>     drm/i915: Check live status before reading edid
>>>
>>>
>>>
>>> The regression was introduced as of v4.4-rc1.
>>>
>>> I was hoping to get your feedback, since you are the patch author.  Do
>>> think increasing the number of tries in intel_hdmi_detect() is worth
>>> trying?  Do you think gathering any additional data will help diagnose
>>> this issue, or would it be best to submit a revert request?
> Thanks for the info.  I will have all of these commits tested.
>
>
>> There are at least the following commits claiming to fix issues in the
>> above commit. Please make sure you have them.
>>
>> BR,
>> Jani.
>>
>>
>> commit 8d409cb3e8a24196be7271defafd4638f3e0b514
>> Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
>> Date:   Wed Feb 10 19:59:05 2016 +0200
>>
>>     drm/i915: Fix hpd live status bits for g4x
>>
>> commit 3d8acd1f667b45c531401c8f0c2033072e32a05d
>> Author: Gary Wang <gary.c.wang@intel.com>
>> Date:   Wed Dec 23 16:11:35 2015 +0800
>>
>>     drm/i915: increase the tries for HDMI hotplug live status checking
>>
>> commit 97f9010af05c15e0b7e6b4ef6ff8cb0ebb7e7715
>> Author: Daniel Vetter <daniel.vetter@ffwll.ch>
>> Date:   Fri Dec 11 19:44:15 2015 +0100
>>
>>     drm/i915: mdelay(10) considered harmful
>>
>> commit 0f5a9be15797f78c9a34e432f26c796165b6e49a
>> Author: Imre Deak <imre.deak@intel.com>
>> Date:   Fri Nov 27 18:55:29 2015 +0200
>>
>>     drm/i915: take a power domain reference while checking the HDMI live status
>>
>>
>>
>>
Hi Jani,

Applying the following commit did indeed fix the original bug[0]:

commit 8d409cb3e8a24196be7271defafd4638f3e0b514
Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
Date:   Wed Feb 10 19:59:05 2016 +0200

    drm/i915: Fix hpd live status bits for g4x



However, it also introduced a new bug, which is covered in that bug
report.  The new bug is that after locking/unlocking the screen, all the
windows get shuffled around in a manner that is consistent with X
deciding that it's single-headed again, and then back to double headed. 
This only happens when I build a kernel with both commit 237ed86c AND
commit 8d409cb3e.  If I revert 237ed86c and keep only 8d409cb3e both the
original bug and the new bug go away.  Do you think commit 237ed86c is
still even needed now that 8d409cb3e has landed?  Maybe the new bug is
due to the interaction between 237ed86c and 8d409cb3e.

Thanks,

Joe

[0] http://pad.lv/1543683

Re: [4.4-rc1][Regression] drm/i915: Check live status before reading edid

[Joseph Salisbury]

On 03/28/2016 02:39 PM, Joseph Salisbury wrote:
> On 03/02/2016 04:58 PM, Joseph Salisbury wrote:
>> On 02/29/2016 04:33 AM, Jani Nikula wrote:
>>> On Wed, 24 Feb 2016, Joseph Salisbury <joseph.salisbury@canonical.com> wrote:
>>>> Hi Sonika,
>>>>
>>>> A kernel bug report was opened against Ubuntu [0].  After a kernel
>>>> bisect, it was found that reverting the following commit resolved this bug:
>>>>
>>>> commit 237ed86c693d8a8e4db476976aeb30df4deac74b
>>>> Author: Sonika Jindal <sonika.jindal@intel.com>
>>>> Date:   Tue Sep 15 09:44:20 2015 +0530
>>>>
>>>>     drm/i915: Check live status before reading edid
>>>>
>>>>
>>>>
>>>> The regression was introduced as of v4.4-rc1.
>>>>
>>>> I was hoping to get your feedback, since you are the patch author.  Do
>>>> think increasing the number of tries in intel_hdmi_detect() is worth
>>>> trying?  Do you think gathering any additional data will help diagnose
>>>> this issue, or would it be best to submit a revert request?
>> Thanks for the info.  I will have all of these commits tested.
>>
>>
>>> There are at least the following commits claiming to fix issues in the
>>> above commit. Please make sure you have them.
>>>
>>> BR,
>>> Jani.
>>>
>>>
>>> commit 8d409cb3e8a24196be7271defafd4638f3e0b514
>>> Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
>>> Date:   Wed Feb 10 19:59:05 2016 +0200
>>>
>>>     drm/i915: Fix hpd live status bits for g4x
>>>
>>> commit 3d8acd1f667b45c531401c8f0c2033072e32a05d
>>> Author: Gary Wang <gary.c.wang@intel.com>
>>> Date:   Wed Dec 23 16:11:35 2015 +0800
>>>
>>>     drm/i915: increase the tries for HDMI hotplug live status checking
>>>
>>> commit 97f9010af05c15e0b7e6b4ef6ff8cb0ebb7e7715
>>> Author: Daniel Vetter <daniel.vetter@ffwll.ch>
>>> Date:   Fri Dec 11 19:44:15 2015 +0100
>>>
>>>     drm/i915: mdelay(10) considered harmful
>>>
>>> commit 0f5a9be15797f78c9a34e432f26c796165b6e49a
>>> Author: Imre Deak <imre.deak@intel.com>
>>> Date:   Fri Nov 27 18:55:29 2015 +0200
>>>
>>>     drm/i915: take a power domain reference while checking the HDMI live status
>>>
>>>
>>>
>>>
> Hi Jani,
>
> Applying the following commit did indeed fix the original bug[0]:
>
> commit 8d409cb3e8a24196be7271defafd4638f3e0b514
> Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Date:   Wed Feb 10 19:59:05 2016 +0200
>
>     drm/i915: Fix hpd live status bits for g4x
>
>
>
> However, it also introduced a new bug, which is covered in that bug
> report.  The new bug is that after locking/unlocking the screen, all the
> windows get shuffled around in a manner that is consistent with X
> deciding that it's single-headed again, and then back to double headed. 
> This only happens when I build a kernel with both commit 237ed86c AND
> commit 8d409cb3e.  If I revert 237ed86c and keep only 8d409cb3e both the
> original bug and the new bug go away.  Do you think commit 237ed86c is
> still even needed now that 8d409cb3e has landed?  Maybe the new bug is
> due to the interaction between 237ed86c and 8d409cb3e.
>
> Thanks,
>
> Joe
>
> [0] http://pad.lv/1543683
>
>
>
>
>
Hello,

Is there any addition debug data we can collect to debug the new bug
that commit 8d409cb3e introduced?

Thanks,

Joe