Re: [PATCH] drm/i915: unconditionally unlock panel regs

From: Jim Gettys <jg@freedesktop.org>
To: intel-gfx@lists.freedesktop.org
Subject: Re: [PATCH] drm/i915: unconditionally unlock panel regs
Date: Wed, 15 Dec 2010 12:27:26 -0500	[thread overview]
Message-ID: <4D08FA7E.4060402@freedesktop.org> (raw)
In-Reply-To: <20101214131512.1ac839c4@jbarnes-desktop>

On 12/14/2010 04:15 PM, Jesse Barnes wrote:
> On Tue, 14 Dec 2010 20:45:14 +0000
> Chris Wilson<chris@chris-wilson.co.uk>  wrote:
>
>> >  On Tue, 14 Dec 2010 12:17:59 -0800, Jesse Barnes<jbarnes@virtuousgeek.org>  wrote:
>>> >  >  In the panel_on function we skip everything if the panel is already
>>> >  >  powered up.  However, if it's powered up but not unlocked, subsequent
>>> >  >  register writes may fail.
>>> >  >
>>> >  >  So unlock the regs regardless of the panel state to allow other mode
>>> >  >  setting programming to occur normally.
>> >
>> >  That looks to be consistent with other [ab]users of PP_CONTROL. Can you
>> >  tidy up the function to remove the duplicate code afterwards?
>> >  -Chris
> Sure, her eyou go.

Unfortunately, this patch does not seem to fix my intermittent boot 
problem on the HP 2540p.  I sort of wonder if Airlied and I have 
different BIOS's; I got mine very early on, and have not updated its 
BIOS.  This hypothesis would indicate some bit in some register isn't 
getting set.

                           - Jim

>
> -- Jesse Barnes, Intel Open Source Technology Center >From
> 78b4ed4faf42b62de6d8a23dda8120c410488c82 Mon Sep 17 00:00:00 2001 From:
> Jesse Barnes <jbarnes@virtuousgeek.org> Date: Tue, 14 Dec 2010 13:14:07
> -0800 Subject: [PATCH] drm/i915: unconditionally unlock panel regs In
> the panel_on function we skip everything if the panel is already powered
> up. However, if it's powered up but not unlocked, subsequent register
> writes may fail. So unlock the regs regardless of the panel state to
> allow other mode setting programming to occur normally. [Still waiting
> to hear from bug reporters & testers on this one, but it does get my
> Vaio working again, with or without the eDP VBT patch reverted.]
> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> ---
> drivers/gpu/drm/i915/intel_dp.c | 10 +++++++--- 1 files changed, 7
> insertions(+), 3 deletions(-) diff --git
> a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index f74a706..ddfd585 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++
> b/drivers/gpu/drm/i915/intel_dp.c @@ -818,17 +818,21 @@ static bool
> ironlake_edp_panel_on (struct intel_dp *intel_dp) struct
> drm_i915_private *dev_priv = dev->dev_private; u32 pp, idle_on_mask =
> PP_ON | PP_SEQUENCE_STATE_ON_IDLE; + /* Always unlock the protected regs
> so other writes work */ + pp = I915_READ(PCH_PP_CONTROL); + pp |=
> PANEL_UNLOCK_REGS; + I915_WRITE(PCH_PP_CONTROL, pp); +
> POSTING_READ(PCH_PP_CONTROL); + if (I915_READ(PCH_PP_STATUS) & PP_ON)
> return true; - pp = I915_READ(PCH_PP_CONTROL); - /* ILK workaround:
> disable reset around power sequence */ pp &= ~PANEL_POWER_RESET;
> I915_WRITE(PCH_PP_CONTROL, pp); POSTING_READ(PCH_PP_CONTROL); - pp |=
> PANEL_UNLOCK_REGS | POWER_TARGET_ON; + pp |= POWER_TARGET_ON;
> I915_WRITE(PCH_PP_CONTROL, pp); POSTING_READ(PCH_PP_CONTROL);
> -- 1.7.0.4 _______________________________________________ Intel-gfx
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