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From: Anshuman Gupta <anshuman.gupta@intel.com>
To: Imre Deak <imre.deak@intel.com>
Cc: intel-gfx@lists.freedesktop.org, ville.syrjala@linux.intel.com,
	stable@vger.kernel.org
Subject: Re: [RFC 2/2] drm/i915/display: Protect pipe_update against dc3co exit
Date: Mon, 30 Nov 2020 21:46:59 +0530	[thread overview]
Message-ID: <20201130161658.GA30377@intel.com> (raw)
In-Reply-To: <20201130152832.GB2348711@ideak-desk.fi.intel.com>

On 2020-11-30 at 17:28:32 +0200, Imre Deak wrote:
> On Mon, Nov 30, 2020 at 02:46:46PM +0530, Anshuman Gupta wrote:
> > At usual case DC3CO exit happen automatically by DMC f/w whenever
> > PSR2 clears idle. This happens smoothly by DMC f/w to work with flips.
> > But there are certain scenario where DC3CO  Disallowed by driver
> > asynchronous with flips. In such scenario display engine could
> > be already in DC3CO state and driver has disallowed it,
> > It initiates DC3CO exit sequence in DMC f/w which requires a
> > dc3co exit delay of 200us in driver.
> > It requires to protect intel_pipe_update_{update_end} with
> > dc3co exit delay.
> > 
> > Cc: Imre Deak <imre.deak@intel.com>
> > Cc: <stable@vger.kernel.org>
> > Signed-off-by: Anshuman Gupta <anshuman.gupta@intel.com>
> 
> To make sure that it doesn't hide the root cause (or affects unrelated
> platforms), I'd only add locking around DC3co changes with a new lock,
> using lock/unlock helpers in intel_display_power.c called from
> intel_pipe_update_start/end.
> 
> Also please submit this patch separately, w/o the optimization in patch
> 1/2, so we know that this change fixes the problem.
Thanks imre for review comments, i will send a new patch with review comments fixed.
Anshuman Gupta. 
> 
> --Imre
> 
> > ---
> >  drivers/gpu/drm/i915/display/intel_display.c | 3 +++
> >  1 file changed, 3 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> > index ba26545392bc..3b81b98c0daf 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > @@ -15924,6 +15924,8 @@ static void intel_update_crtc(struct intel_atomic_state *state,
> >  	else
> >  		intel_fbc_enable(state, crtc);
> >  
> > +	/* Protect intel_pipe_update_{start,end} with power_domians lock */
> > +	mutex_lock(&dev_priv->power_domains.lock);
> >  	/* Perform vblank evasion around commit operation */
> >  	intel_pipe_update_start(new_crtc_state);
> >  
> > @@ -15935,6 +15937,7 @@ static void intel_update_crtc(struct intel_atomic_state *state,
> >  		i9xx_update_planes_on_crtc(state, crtc);
> >  
> >  	intel_pipe_update_end(new_crtc_state);
> > +	mutex_unlock(&dev_prive->power_domains.lock);
> >  
> >  	/*
> >  	 * We usually enable FIFO underrun interrupts as part of the
> > -- 
> > 2.26.2
> > 

WARNING: multiple messages have this Message-ID (diff)
From: Anshuman Gupta <anshuman.gupta@intel.com>
To: Imre Deak <imre.deak@intel.com>
Cc: intel-gfx@lists.freedesktop.org, stable@vger.kernel.org
Subject: Re: [Intel-gfx] [RFC 2/2] drm/i915/display: Protect pipe_update against dc3co exit
Date: Mon, 30 Nov 2020 21:46:59 +0530	[thread overview]
Message-ID: <20201130161658.GA30377@intel.com> (raw)
In-Reply-To: <20201130152832.GB2348711@ideak-desk.fi.intel.com>

On 2020-11-30 at 17:28:32 +0200, Imre Deak wrote:
> On Mon, Nov 30, 2020 at 02:46:46PM +0530, Anshuman Gupta wrote:
> > At usual case DC3CO exit happen automatically by DMC f/w whenever
> > PSR2 clears idle. This happens smoothly by DMC f/w to work with flips.
> > But there are certain scenario where DC3CO  Disallowed by driver
> > asynchronous with flips. In such scenario display engine could
> > be already in DC3CO state and driver has disallowed it,
> > It initiates DC3CO exit sequence in DMC f/w which requires a
> > dc3co exit delay of 200us in driver.
> > It requires to protect intel_pipe_update_{update_end} with
> > dc3co exit delay.
> > 
> > Cc: Imre Deak <imre.deak@intel.com>
> > Cc: <stable@vger.kernel.org>
> > Signed-off-by: Anshuman Gupta <anshuman.gupta@intel.com>
> 
> To make sure that it doesn't hide the root cause (or affects unrelated
> platforms), I'd only add locking around DC3co changes with a new lock,
> using lock/unlock helpers in intel_display_power.c called from
> intel_pipe_update_start/end.
> 
> Also please submit this patch separately, w/o the optimization in patch
> 1/2, so we know that this change fixes the problem.
Thanks imre for review comments, i will send a new patch with review comments fixed.
Anshuman Gupta. 
> 
> --Imre
> 
> > ---
> >  drivers/gpu/drm/i915/display/intel_display.c | 3 +++
> >  1 file changed, 3 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> > index ba26545392bc..3b81b98c0daf 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > @@ -15924,6 +15924,8 @@ static void intel_update_crtc(struct intel_atomic_state *state,
> >  	else
> >  		intel_fbc_enable(state, crtc);
> >  
> > +	/* Protect intel_pipe_update_{start,end} with power_domians lock */
> > +	mutex_lock(&dev_priv->power_domains.lock);
> >  	/* Perform vblank evasion around commit operation */
> >  	intel_pipe_update_start(new_crtc_state);
> >  
> > @@ -15935,6 +15937,7 @@ static void intel_update_crtc(struct intel_atomic_state *state,
> >  		i9xx_update_planes_on_crtc(state, crtc);
> >  
> >  	intel_pipe_update_end(new_crtc_state);
> > +	mutex_unlock(&dev_prive->power_domains.lock);
> >  
> >  	/*
> >  	 * We usually enable FIFO underrun interrupts as part of the
> > -- 
> > 2.26.2
> > 
_______________________________________________
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  reply	other threads:[~2020-11-30 16:31 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-30  9:16 [Intel-gfx] [RFC 0/2] Display glitches fixes Anshuman Gupta
2020-11-30  9:16 ` [Intel-gfx] [RFC 1/2] drm/i915/dp: optimize pps_lock wherever required Anshuman Gupta
2020-11-30  9:16 ` [RFC 2/2] drm/i915/display: Protect pipe_update against dc3co exit Anshuman Gupta
2020-11-30  9:16   ` [Intel-gfx] " Anshuman Gupta
2020-11-30 15:28   ` Imre Deak
2020-11-30 15:28     ` [Intel-gfx] " Imre Deak
2020-11-30 16:16     ` Anshuman Gupta [this message]
2020-11-30 16:16       ` Anshuman Gupta
2020-12-04  8:10     ` Anshuman Gupta
2020-12-04  8:10       ` [Intel-gfx] " Anshuman Gupta
2020-12-04 15:51       ` Ville Syrjälä
2020-12-04 15:51         ` [Intel-gfx] " Ville Syrjälä
2020-12-07  7:57         ` Anshuman Gupta
2020-12-07  7:57           ` [Intel-gfx] " Anshuman Gupta
2020-12-08  9:11         ` Anshuman Gupta
2020-12-08  9:11           ` [Intel-gfx] " Anshuman Gupta
2020-11-30 15:50 ` [Intel-gfx] ✗ Fi.CI.BUILD: failure for Display glitches fixes Patchwork

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