[Intel-gfx] [PATCH 6/7] drm/i915/psr: Remove partial PSR support on multiple transcoders

Dhinakaran Pandiyan dhinakaran.pandiyan at intel.com
Thu Apr 4 22:06:45 UTC 2019


On Thu, 2019-04-04 at 14:41 -0700, Dhinakaran Pandiyan wrote:
> On Thu, 2019-04-04 at 14:20 -0700, Rodrigo Vivi wrote:
> > On Thu, Apr 04, 2019 at 12:40:34PM -0700, Souza, Jose wrote:
> > > On Wed, 2019-04-03 at 17:31 -0700, Rodrigo Vivi wrote:
> > > > On Wed, Apr 03, 2019 at 04:35:38PM -0700, José Roberto de Souza
> > > > wrote:
> > > > > PSR is only supported in eDP transcoder and there is only one
> > > > > instance of it, so lets drop all of this code.
> > > > 
> > > > Is this sentence true? I mean, in the way it is written it
> > > > seems like HW doesn't actually support it...
> > > > Or should we re-phrase for we are not really enabling support
> > > > for other transcoders than eDP and we do not have plans to do
> > > > it so soon so let's clean the code...
> > > > or something like that?
> > > 
> > > Okay, what about replace it for:
> > > 
> > > Since BDW all transcoders have PSR registers but only EDP transcoder
> > > can drive a EDP panel and as PSR is only part of the EDP specification,
> > > for real usage PSR is only supported in EDP panel, so lets drop all of
> > > this useless code.
> > 
> > well, this still looks like HW limitation. If PSR is supported by HW on
> > different transcoders is because there's some possibility of adding
> > eDP on other transcoders. They wouldn't waste so many register space
> > if that wasn't the case.
> > 
> > Even though we have a dedicated transcoder for eDP I don't
> > believe we can assume that eDP is not supported on the other ones.
> > 
> 
> Why not write something like (or exactly) this 
> 
> "i915 does not support enabling PSR on any transcoder other than eDP. Clean up
> the misleading non-eDP code that currently exists to allow for the rework of
> PSR
> register definitions in the next patch"
> 
> 
> -DK
> > > 
> > > 
> > > 
> > > > 
> > > > > Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> > > > > Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> > > > > Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> > > > > ---
> > > > >  drivers/gpu/drm/i915/i915_reg.h  |  17 +---
> > > > >  drivers/gpu/drm/i915/intel_psr.c | 147 ++++++++-------------------
> > > > > ----
> > > > >  2 files changed, 42 insertions(+), 122 deletions(-)
> > > > > 
> > > > > diff --git a/drivers/gpu/drm/i915/i915_reg.h
> > > > > b/drivers/gpu/drm/i915/i915_reg.h
> > > > > index c59cfa83dbaf..18e2991b376d 100644
> > > > > --- a/drivers/gpu/drm/i915/i915_reg.h
> > > > > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > > > > @@ -4241,13 +4241,9 @@ enum {
> > > > >  /* Bspec claims those aren't shifted but stay at 0x64800 */
> > > > >  #define EDP_PSR_IMR				_MMIO(0x64834)
> > > > >  #define EDP_PSR_IIR				_MMIO(0x64838)
> > > > > -#define   EDP_PSR_ERROR(shift)			(1 << ((shift)
> > > > > + 2))
> > > > > -#define   EDP_PSR_POST_EXIT(shift)		(1 << ((shift) + 1))
> > > > > -#define   EDP_PSR_PRE_ENTRY(shift)		(1 << (shift))
> > > > > -#define   EDP_PSR_TRANSCODER_C_SHIFT		24
> > > > > -#define   EDP_PSR_TRANSCODER_B_SHIFT		16
> > > > > -#define   EDP_PSR_TRANSCODER_A_SHIFT		8
> > > > > -#define   EDP_PSR_TRANSCODER_EDP_SHIFT		0
> > > > > +#define   EDP_PSR_ERROR				(1 << 2)
> > > > > +#define   EDP_PSR_POST_EXIT			(1 << 1)
> > > > > +#define   EDP_PSR_PRE_ENTRY			(1 << 0)
> > > > >  
> > > > >  #define EDP_PSR_AUX_CTL				_MMIO(dev_priv-
> > > > > > psr_mmio_base + 0x10)
> > > > > 
> > > > >  #define   EDP_PSR_AUX_CTL_TIME_OUT_MASK		(3 << 26)
> > > > > @@ -4312,12 +4308,7 @@ enum {
> > > > >  #define   EDP_PSR2_IDLE_FRAME_MASK	0xf
> > > > >  #define   EDP_PSR2_IDLE_FRAME_SHIFT	0
> > > > >  
> > > > > -#define _PSR_EVENT_TRANS_A			0x60848
> > > > > -#define _PSR_EVENT_TRANS_B			0x61848
> > > > > -#define _PSR_EVENT_TRANS_C			0x62848
> > > > > -#define _PSR_EVENT_TRANS_D			0x63848
> > > > > -#define _PSR_EVENT_TRANS_EDP			0x6F848
> > > > > -#define PSR_EVENT(trans)			_MMIO_TRANS2(trans,
> > > > > _PSR_EVENT_TRANS_A)
> > > > > +#define PSR_EVENT				_MMIO(0x6F848)
> > > > >  #define  PSR_EVENT_PSR2_WD_TIMER_EXPIRE		(1 << 17)
> > > > >  #define  PSR_EVENT_PSR2_DISABLED		(1 << 16)
> > > > >  #define  PSR_EVENT_SU_DIRTY_FIFO_UNDERRUN	(1 << 15)
> > > > > diff --git a/drivers/gpu/drm/i915/intel_psr.c
> > > > > b/drivers/gpu/drm/i915/intel_psr.c
> > > > > index bb97c1657493..b984e005b72e 100644
> > > > > --- a/drivers/gpu/drm/i915/intel_psr.c
> > > > > +++ b/drivers/gpu/drm/i915/intel_psr.c
> > > > > @@ -84,46 +84,12 @@ static bool intel_psr2_enabled(struct
> > > > > drm_i915_private *dev_priv,
> > > > >  	}
> > > > >  }
> > > > >  
> > > > > -static int edp_psr_shift(enum transcoder cpu_transcoder)
> > > > > -{
> > > > > -	switch (cpu_transcoder) {
> > > > > -	case TRANSCODER_A:
> > > > > -		return EDP_PSR_TRANSCODER_A_SHIFT;
> > > > > -	case TRANSCODER_B:
> > > > > -		return EDP_PSR_TRANSCODER_B_SHIFT;
> > > > > -	case TRANSCODER_C:
> > > > > -		return EDP_PSR_TRANSCODER_C_SHIFT;
> > > > > -	default:
> > > > > -		MISSING_CASE(cpu_transcoder);
> > > > > -		/* fallthrough */
> > > > > -	case TRANSCODER_EDP:
> > > > > -		return EDP_PSR_TRANSCODER_EDP_SHIFT;
> > > > > -	}
> > > > > -}
> > > > > -
> > > > >  void intel_psr_irq_control(struct drm_i915_private *dev_priv, u32
> > > > > debug)
> > > > >  {
> > > > > -	u32 debug_mask, mask;
> > > > > -	enum transcoder cpu_transcoder;
> > > > > -	u32 transcoders = BIT(TRANSCODER_EDP);
> > > > > -
> > > > > -	if (INTEL_GEN(dev_priv) >= 8)
> > > > > -		transcoders |= BIT(TRANSCODER_A) |
> > > > > -			       BIT(TRANSCODER_B) |
> > > > > -			       BIT(TRANSCODER_C);
> > > > > -
> > > > > -	debug_mask = 0;
> > > > > -	mask = 0;
> > > > > -	for_each_cpu_transcoder_masked(dev_priv, cpu_transcoder,
> > > > > transcoders) {
> > > > > -		int shift = edp_psr_shift(cpu_transcoder);
> > > > > -
> > > > > -		mask |= EDP_PSR_ERROR(shift);
> > > > > -		debug_mask |= EDP_PSR_POST_EXIT(shift) |
> > > > > -			      EDP_PSR_PRE_ENTRY(shift);
> > > > > -	}
> > > > > +	u32 mask = EDP_PSR_ERROR;
> > > > >  
> > > > >  	if (debug & I915_PSR_DEBUG_IRQ)
> > > > > -		mask |= debug_mask;
> > > > > +		mask |= EDP_PSR_POST_EXIT | EDP_PSR_PRE_ENTRY;
> > > > >  
> > > > >  	I915_WRITE(EDP_PSR_IMR, ~mask);
> > > > >  }
> > > > > @@ -167,62 +133,47 @@ static void psr_event_print(u32 val, bool
> > > > > psr2_enabled)
> > > > >  
> > > > >  void intel_psr_irq_handler(struct drm_i915_private *dev_priv, u32
> > > > > psr_iir)
> > > > >  {
> > > > > -	u32 transcoders = BIT(TRANSCODER_EDP);
> > > > > -	enum transcoder cpu_transcoder;
> > > > > -	ktime_t time_ns =  ktime_get();
> > > > > -	u32 mask = 0;
> > > > > +	ktime_t time_ns = ktime_get();
> > > > >  
> > > > > -	if (INTEL_GEN(dev_priv) >= 8)
> > > > > -		transcoders |= BIT(TRANSCODER_A) |
> > > > > -			       BIT(TRANSCODER_B) |
> > > > > -			       BIT(TRANSCODER_C);
> > > > > -
> > > > > -	for_each_cpu_transcoder_masked(dev_priv, cpu_transcoder,
> > > > > transcoders) {
> > > > > -		int shift = edp_psr_shift(cpu_transcoder);
> > > > > -
> > > > > -		if (psr_iir & EDP_PSR_ERROR(shift)) {
> > > > > -			DRM_WARN("[transcoder %s] PSR aux error\n",
> > > > > -				 transcoder_name(cpu_transcoder));
> > > > > -
> > > > > -			dev_priv->psr.irq_aux_error = true;
> > > > > -
> > > > > -			/*
> > > > > -			 * If this interruption is not masked it will
> > > > > keep
> > > > > -			 * interrupting so fast that it prevents the
> > > > > scheduled
> > > > > -			 * work to run.
> > > > > -			 * Also after a PSR error, we don't want to arm
> > > > > PSR
> > > > > -			 * again so we don't care about unmask the
> > > > > interruption
> > > > > -			 * or unset irq_aux_error.
> > > > > -			 */
> > > > > -			mask |= EDP_PSR_ERROR(shift);
> > > > > -		}

What's really the strategy though? I hope we aren't planning to add this code
back again.



More information about the Intel-gfx mailing list