[Intel-gfx] [PATCH 3/5] drm/i915: fix VDD override off wait

[Patrik Jakobsson]

On Thu, Feb 6, 2014 at 8:30 PM, Paulo Zanoni <przanoni at gmail.com> wrote:
> 2014-02-06 15:22 GMT-02:00 Chris Wilson <chris at chris-wilson.co.uk>:
>> On Thu, Feb 06, 2014 at 06:16:02PM +0100, Patrik Jakobsson wrote:
>>> On Fri, Dec 6, 2013 at 8:47 PM, Jesse Barnes <jbarnes at virtuousgeek.org> wrote:
>>> > On Fri,  6 Dec 2013 17:32:42 -0200
>>> > Paulo Zanoni <przanoni at gmail.com> wrote:
>>> >
>>> >> From: Paulo Zanoni <paulo.r.zanoni at intel.com>
>>> >>
>>> >> If we're disabling the VDD override bit and the panel is enabled, we
>>> >> don't need to wait for anything. If the panel is disabled, then we
>>> >> need to actually wait for panel_power_cycle_delay, not
>>> >> panel_power_down_delay, because the power down delay was already
>>> >> respected when we disabled the panel.
>>> >>
>>> >> Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
>>> >> ---
>>> >>  drivers/gpu/drm/i915/intel_dp.c | 4 +++-
>>> >>  1 file changed, 3 insertions(+), 1 deletion(-)
>>> >>
>>> >> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
>>> >> index fe327ce..a2aace2 100644
>>> >> --- a/drivers/gpu/drm/i915/intel_dp.c
>>> >> +++ b/drivers/gpu/drm/i915/intel_dp.c
>>> >> @@ -1142,7 +1142,9 @@ static void ironlake_panel_vdd_off_sync(struct intel_dp *intel_dp)
>>> >>               /* Make sure sequencer is idle before allowing subsequent activity */
>>> >>               DRM_DEBUG_KMS("PP_STATUS: 0x%08x PP_CONTROL: 0x%08x\n",
>>> >>               I915_READ(pp_stat_reg), I915_READ(pp_ctrl_reg));
>>> >> -             msleep(intel_dp->panel_power_down_delay);
>>> >> +
>>> >> +             if ((pp & POWER_TARGET_ON) == 0)
>>> >> +                     msleep(intel_dp->panel_power_cycle_delay);
>>> >>       }
>>> >>  }
>>> >>
>>> >
>>> > Lemme check the eDP docs on this one...  it's supposed to be T12, which
>>> > is the time between power cycles.  Yeah that matches what we're using
>>> > elsewhere, so:
>>> >
>>> > Reviewed-by: Jesse Barnes <jbarnes at virtuousgeek.org>
>>>
>>> Starting with this patch I get a blank screen when booting my MacBook Air 6,2.
>>> Reverting only this patch on top of 3.14-rc1 doesn't help so it's most likely
>>> the entire series that needs to be looked at.
>>>
>>> Doing a suspend/resume fixes the problem.
>
> Oh, well, at least we didn't break suspend/resume :)
>
> I just requested some information at the bugzilla entry created by
> Chris. Can you please provide the requested files there, and move the
> discussion to bugzilla?
>
>>
>> I've filed this as https://bugs.freedesktop.org/show_bug.cgi?id=74628
>
> Thanks for doing this! It's too easy to forget about mailing-list-only
> bug reports.

I was just a bit lazy. The dmesg is up on bugzilla.

Thanks
Patrik