[Intel-gfx] [PATCH v3] drm/i915/psr: Fix PSR_IMR/IIR field handling

Souza, Jose jose.souza at intel.com
Thu Sep 29 13:18:17 UTC 2022


On Thu, 2022-09-29 at 06:16 -0700, José Roberto de Souza wrote:
> On Tue, 2022-09-27 at 14:09 +0300, Jouni Högander wrote:
> > Current PSR code is supposed to use TRANSCODER_EDP to force 0 shift for
> > bits in PSR_IMR/IIR registers:
> > 
> > /*
> >  * gen12+ has registers relative to transcoder and one per transcoder
> >  * using the same bit definition: handle it as TRANSCODER_EDP to force
> >  * 0 shift in bit definition
> >  */
> > 
> > At the time of writing the code assumption "TRANSCODER_EDP == 0" was made.
> > This is not the case and all fields in PSR_IMR and PSR_IIR are shifted
> > incorrectly if DISPLAY_VER >= 12.
> > 
> > Fix this by adding separate register field defines for >=12 and add bit
> > getter functions to keep code readability.
> > 
> > v3:
> >  - Add separate register field defines (José)
> >  - Add bit getter functions (José)
> > v2:
> >  - Improve commit message (José)

Also missing the Fixes tag, so this gets backported to stable kernels.

> > 
> > Signed-off-by: Jouni Högander <jouni.hogander at intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_psr.c | 84 ++++++++++++++----------
> >  drivers/gpu/drm/i915/i915_reg.h          | 16 +++--
> >  2 files changed, 62 insertions(+), 38 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
> > index 9def8d9fade6..d7b08a7da9e9 100644
> > --- a/drivers/gpu/drm/i915/display/intel_psr.c
> > +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> > @@ -116,34 +116,56 @@ static bool psr2_global_enabled(struct intel_dp *intel_dp)
> >  	}
> >  }
> >  
> > +static u32 psr_irq_psr_error_bit_get(struct intel_dp *intel_dp)
> > +{
> > +	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
> > +
> > +	return DISPLAY_VER(dev_priv) >= 12 ? TGL_EDP_PSR_ERROR :
> > +		EDP_PSR_ERROR(intel_dp->psr.transcoder);
> 
> Drop the "_EDP", just go with TGL_PSR_ERROR... there is no reference to EDP or any transcoder in TGL+ it is one register per transcoder.
> 
> > +}
> > +
> > +static u32 psr_irq_post_exit_bit_get(struct intel_dp *intel_dp)
> > +{
> > +	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
> > +
> > +	return DISPLAY_VER(dev_priv) >= 12 ? TGL_EDP_PSR_POST_EXIT :
> > +		EDP_PSR_POST_EXIT(intel_dp->psr.transcoder);
> > +}
> > +
> > +static u32 psr_irq_pre_entry_bit_get(struct intel_dp *intel_dp)
> > +{
> > +	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
> > +
> > +	return DISPLAY_VER(dev_priv) >= 12 ? TGL_EDP_PSR_PRE_ENTRY :
> > +		EDP_PSR_PRE_ENTRY(intel_dp->psr.transcoder);
> > +}
> > +
> > +static u32 psr_irq_mask_get(struct intel_dp *intel_dp)
> > +{
> > +	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
> > +
> > +	return DISPLAY_VER(dev_priv) >= 12 ? TGL_EDP_PSR_MASK :
> > +		EDP_PSR_MASK(intel_dp->psr.transcoder);
> > +}
> > +
> >  static void psr_irq_control(struct intel_dp *intel_dp)
> >  {
> >  	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
> > -	enum transcoder trans_shift;
> >  	i915_reg_t imr_reg;
> >  	u32 mask, val;
> >  
> > -	/*
> > -	 * gen12+ has registers relative to transcoder and one per transcoder
> > -	 * using the same bit definition: handle it as TRANSCODER_EDP to force
> > -	 * 0 shift in bit definition
> > -	 */
> > -	if (DISPLAY_VER(dev_priv) >= 12) {
> > -		trans_shift = 0;
> > +	if (DISPLAY_VER(dev_priv) >= 12)
> >  		imr_reg = TRANS_PSR_IMR(intel_dp->psr.transcoder);
> > -	} else {
> > -		trans_shift = intel_dp->psr.transcoder;
> > +	else
> >  		imr_reg = EDP_PSR_IMR;
> > -	}
> >  
> > -	mask = EDP_PSR_ERROR(trans_shift);
> > +	mask = psr_irq_psr_error_bit_get(intel_dp);
> >  	if (intel_dp->psr.debug & I915_PSR_DEBUG_IRQ)
> > -		mask |= EDP_PSR_POST_EXIT(trans_shift) |
> > -			EDP_PSR_PRE_ENTRY(trans_shift);
> > +		mask |= psr_irq_post_exit_bit_get(intel_dp) |
> > +			psr_irq_pre_entry_bit_get(intel_dp);
> >  
> > -	/* Warning: it is masking/setting reserved bits too */
> >  	val = intel_de_read(dev_priv, imr_reg);
> > -	val &= ~EDP_PSR_TRANS_MASK(trans_shift);
> > +	val &= ~psr_irq_mask_get(intel_dp);
> >  	val |= ~mask;
> >  	intel_de_write(dev_priv, imr_reg, val);
> >  }
> > @@ -191,25 +213,21 @@ void intel_psr_irq_handler(struct intel_dp *intel_dp, u32 psr_iir)
> >  	enum transcoder cpu_transcoder = intel_dp->psr.transcoder;
> >  	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
> >  	ktime_t time_ns =  ktime_get();
> > -	enum transcoder trans_shift;
> >  	i915_reg_t imr_reg;
> >  
> > -	if (DISPLAY_VER(dev_priv) >= 12) {
> > -		trans_shift = 0;
> > +	if (DISPLAY_VER(dev_priv) >= 12)
> >  		imr_reg = TRANS_PSR_IMR(intel_dp->psr.transcoder);
> > -	} else {
> > -		trans_shift = intel_dp->psr.transcoder;
> > +	else
> >  		imr_reg = EDP_PSR_IMR;
> > -	}
> >  
> > -	if (psr_iir & EDP_PSR_PRE_ENTRY(trans_shift)) {
> > +	if (psr_iir & psr_irq_pre_entry_bit_get(intel_dp)) {
> >  		intel_dp->psr.last_entry_attempt = time_ns;
> >  		drm_dbg_kms(&dev_priv->drm,
> >  			    "[transcoder %s] PSR entry attempt in 2 vblanks\n",
> >  			    transcoder_name(cpu_transcoder));
> >  	}
> >  
> > -	if (psr_iir & EDP_PSR_POST_EXIT(trans_shift)) {
> > +	if (psr_iir & psr_irq_post_exit_bit_get(intel_dp)) {
> >  		intel_dp->psr.last_exit = time_ns;
> >  		drm_dbg_kms(&dev_priv->drm,
> >  			    "[transcoder %s] PSR exit completed\n",
> > @@ -226,7 +244,7 @@ void intel_psr_irq_handler(struct intel_dp *intel_dp, u32 psr_iir)
> >  		}
> >  	}
> >  
> > -	if (psr_iir & EDP_PSR_ERROR(trans_shift)) {
> > +	if (psr_iir & psr_irq_psr_error_bit_get(intel_dp)) {
> >  		u32 val;
> >  
> >  		drm_warn(&dev_priv->drm, "[transcoder %s] PSR aux error\n",
> > @@ -243,7 +261,7 @@ void intel_psr_irq_handler(struct intel_dp *intel_dp, u32 psr_iir)
> >  		 * or unset irq_aux_error.
> >  		 */
> >  		val = intel_de_read(dev_priv, imr_reg);
> > -		val |= EDP_PSR_ERROR(trans_shift);
> > +		val |= psr_irq_psr_error_bit_get(intel_dp);
> >  		intel_de_write(dev_priv, imr_reg, val);
> >  
> >  		schedule_work(&intel_dp->psr.work);
> > @@ -1194,14 +1212,12 @@ static bool psr_interrupt_error_check(struct intel_dp *intel_dp)
> >  	 * first time that PSR HW tries to activate so lets keep PSR disabled
> >  	 * to avoid any rendering problems.
> >  	 */
> > -	if (DISPLAY_VER(dev_priv) >= 12) {
> > +	if (DISPLAY_VER(dev_priv) >= 12)
> >  		val = intel_de_read(dev_priv,
> >  				    TRANS_PSR_IIR(intel_dp->psr.transcoder));
> > -		val &= EDP_PSR_ERROR(0);
> > -	} else {
> > +	else
> >  		val = intel_de_read(dev_priv, EDP_PSR_IIR);
> > -		val &= EDP_PSR_ERROR(intel_dp->psr.transcoder);
> > -	}
> > +	val &= psr_irq_psr_error_bit_get(intel_dp);
> >  	if (val) {
> >  		intel_dp->psr.sink_not_reliable = true;
> >  		drm_dbg_kms(&dev_priv->drm,
> > @@ -2158,9 +2174,9 @@ static void intel_psr_work(struct work_struct *work)
> >  
> >  	/*
> >  	 * We have to make sure PSR is ready for re-enable
> > -	 * otherwise it keeps disabled until next full enable/disable cycle.
> > -	 * PSR might take some time to get fully disabled
> > -	 * and be ready for re-enable.
> > +	 * otherwise it keeps disabled until next full enable/disable
> > +	 * cycle. PSR might take some time to get fully disabled and
> > +	 * be ready for re-enable.
> 
> Non-related change.
> 
> >  	 */
> >  	if (!__psr_wait_for_idle_locked(intel_dp))
> >  		goto unlock;
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> > index 5003a5ffbc6a..3c103aeaa2e4 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -2168,10 +2168,18 @@
> >  #define TRANS_PSR_IIR(tran)			_MMIO_TRANS2(tran, _PSR_IIR_A)
> >  #define   _EDP_PSR_TRANS_SHIFT(trans)		((trans) == TRANSCODER_EDP ? \
> >  						 0 : ((trans) - TRANSCODER_A + 1) * 8)
> > -#define   EDP_PSR_TRANS_MASK(trans)		(0x7 << _EDP_PSR_TRANS_SHIFT(trans))
> > -#define   EDP_PSR_ERROR(trans)			(0x4 << _EDP_PSR_TRANS_SHIFT(trans))
> > -#define   EDP_PSR_POST_EXIT(trans)		(0x2 << _EDP_PSR_TRANS_SHIFT(trans))
> > -#define   EDP_PSR_PRE_ENTRY(trans)		(0x1 << _EDP_PSR_TRANS_SHIFT(trans))
> > +#define   TGL_EDP_PSR_MASK			(0x7)
> > +#define   TGL_EDP_PSR_ERROR			(1 << 2)
> > +#define   TGL_EDP_PSR_POST_EXIT			(1 << 1)
> > +#define   TGL_EDP_PSR_PRE_ENTRY			(1 << 0)
> 
> For new stuff REG_BIT() should be used.
> 
> > +#define   EDP_PSR_MASK(trans)			(TGL_EDP_PSR_MASK <<	\
> > +						 _EDP_PSR_TRANS_SHIFT(trans))
> > +#define   EDP_PSR_ERROR(trans)			(TGL_EDP_PSR_ERROR <<	\
> > +						 _EDP_PSR_TRANS_SHIFT(trans))
> > +#define   EDP_PSR_POST_EXIT(trans)		(TGL_EDP_PSR_POST_EXIT << \
> > +						 _EDP_PSR_TRANS_SHIFT(trans))
> > +#define   EDP_PSR_PRE_ENTRY(trans)		(TGL_EDP_PSR_PRE_ENTRY << \
> > +						 _EDP_PSR_TRANS_SHIFT(trans))
> >  
> >  #define _SRD_AUX_DATA_A				0x60814
> >  #define _SRD_AUX_DATA_EDP			0x6f814
> 



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