[Linux v4.3-rc6] i915: issues with Skylake integrated graphics

[Linux v4.3-rc6] i915: issues with Skylake integrated graphics

[Eric Biggers]

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Hi,

I am testing Linux v4.3-rc6 on a laptop with Intel 'Skylake' integrated
graphics.  The integrated display works, but I noticed several warnings in the
kernel log, and a VGA monitor attached to the HDMI input via a VGA->HDMI adapter
did not work.  Furthermore, the system hung for several seconds during boot.
The two WARNs were:

[    1.078097] WARNING: CPU: 0 PID: 1 at drivers/gpu/drm/i915/intel_pm.c:3321 skl_update_pipe_wm+0x7fa/0x810()
[    1.078097] WARN_ON(p->pixel_rate == 0)
...
[    1.353670] WARNING: CPU: 1 PID: 6 at drivers/gpu/drm/i915/intel_dp.c:854 intel_dp_aux_ch+0x10f/0x6a0()
[    1.353670] dp_aux_ch not started status 0xad40001f

The following error was reported later, when the HDMI input was connected but
the driver failed to report the input as connected:

[   52.553940] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 130

I have attached the full 'dmesg' output for anyone who may find it useful.  

Eric

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Re: [Linux v4.3-rc6] i915: issues with Skylake integrated graphics

[Jani Nikula]

On Fri, 23 Oct 2015, Eric Biggers <ebiggers3@gmail.com> wrote:
> Hi,
>
> I am testing Linux v4.3-rc6 on a laptop with Intel 'Skylake' integrated
> graphics.  The integrated display works, but I noticed several warnings in the
> kernel log, and a VGA monitor attached to the HDMI input via a VGA->HDMI adapter
> did not work.  Furthermore, the system hung for several seconds during boot.
> The two WARNs were:
>
> [    1.078097] WARNING: CPU: 0 PID: 1 at drivers/gpu/drm/i915/intel_pm.c:3321 skl_update_pipe_wm+0x7fa/0x810()
> [    1.078097] WARN_ON(p->pixel_rate == 0)

Please file two separate bugs at [1], one for the above, and another for
the below. Please add drm.debug=14 module parameter, and attach dmesg
all the way from boot to the problem.

Thanks,
Jani.

[1] https://bugs.freedesktop.org/enter_bug.cgi?product=DRI&component=DRM/Intel


> ...
> [    1.353670] WARNING: CPU: 1 PID: 6 at drivers/gpu/drm/i915/intel_dp.c:854 intel_dp_aux_ch+0x10f/0x6a0()
> [    1.353670] dp_aux_ch not started status 0xad40001f
>
> The following error was reported later, when the HDMI input was connected but
> the driver failed to report the input as connected:
>
> [   52.553940] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 130
>
> I have attached the full 'dmesg' output for anyone who may find it useful.  
>
> Eric
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Jani Nikula, Intel Open Source Technology Center

Re: [Linux v4.3-rc6] i915: issues with Skylake integrated graphics

[Eric Biggers]

On Mon, Oct 26, 2015 at 03:28:37PM +0200, Jani Nikula wrote:
> Please file two separate bugs at [1], one for the above, and another for
> the below. Please add drm.debug=14 module parameter, and attach dmesg
> all the way from boot to the problem.

I have filed https://bugs.freedesktop.org/show_bug.cgi?id=92685 for the second
part.  I did not, however, re-experience the first warning (the
"WARN_ON(p->pixel_rate == 0)") after upgrading to Linux v4.3-rc7 and rebooting
several times.

Eric

Re: [Linux v4.3-rc6] i915: issues with Skylake integrated graphics

[Jani Nikula]

On Tue, 27 Oct 2015, Eric Biggers <ebiggers3@gmail.com> wrote:
> On Mon, Oct 26, 2015 at 03:28:37PM +0200, Jani Nikula wrote:
>> Please file two separate bugs at [1], one for the above, and another for
>> the below. Please add drm.debug=14 module parameter, and attach dmesg
>> all the way from boot to the problem.
>
> I have filed https://bugs.freedesktop.org/show_bug.cgi?id=92685 for the second
> part.  I did not, however, re-experience the first warning (the
> "WARN_ON(p->pixel_rate == 0)") after upgrading to Linux v4.3-rc7 and rebooting
> several times.

Thanks for the report.

BR,
Jani.

-- 
Jani Nikula, Intel Open Source Technology Center