[Intel-gfx] [PATCH] drm/i915/vbt: Fix VBT parsing for the PSR section

[Souza, Jose]

On Tue, 2019-07-16 at 15:10 -0700, Pandiyan, Dhinakaran wrote:
> On Tue, 2019-07-16 at 15:03 -0700, Dhinakaran Pandiyan wrote:
> > A single 32-bit PSR2 training pattern field follows the sixteen
> > element
> > array of PSR table entries in the VBT spec. But, we incorrectly
> > define
> > this PSR2 field for each of the PSR table entries. As a result, the
> > PSR1
> > training pattern duration for any panel_type != 0 will be parsed
> > incorrectly. Secondly, PSR2 training pattern durations for VBTs
> > with bdb
> > version >= 226 will also be wrong.
> 
> This was reported and bisected by 
> Aliaksei Urbanski here - 
> https://bugzilla.kernel.org/show_bug.cgi?id=204183
> 
> I'll add Bugzilla after the fix is confirmed.
> 

Oohh it makes sense, thanks for spotting it.

And 2 users reported that it works:
https://bugzilla.kernel.org/show_bug.cgi?id=204183
https://bugs.freedesktop.org/show_bug.cgi?id=111088

Can you also CC kernel stable so the fix is cherry-picked?

Reviewed-by: José Roberto de Souza <jose.souza at intel.com>


> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> Cc: José Roberto de Souza <jose.souza at intel.com>
> Fixes: 88a0d9606aff ("drm/i915/vbt: Parse and use the new field with
> PSR2 TP2/3 wakeup time")z
> Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_bios.c     | 2 +-
>  drivers/gpu/drm/i915/display/intel_vbt_defs.h | 6 +++---
>  2 files changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_bios.c
> b/drivers/gpu/drm/i915/display/intel_bios.c
> index 21501d565327..b416b394b641 100644
> --- a/drivers/gpu/drm/i915/display/intel_bios.c
> +++ b/drivers/gpu/drm/i915/display/intel_bios.c
> @@ -766,7 +766,7 @@ parse_psr(struct drm_i915_private *dev_priv,
> const struct bdb_header *bdb)
>  	}
>  
>  	if (bdb->version >= 226) {
> -		u32 wakeup_time = psr_table->psr2_tp2_tp3_wakeup_time;
> +		u32 wakeup_time = psr->psr2_tp2_tp3_wakeup_time;
>  
>  		wakeup_time = (wakeup_time >> (2 * panel_type)) & 0x3;
>  		switch (wakeup_time) {
> diff --git a/drivers/gpu/drm/i915/display/intel_vbt_defs.h
> b/drivers/gpu/drm/i915/display/intel_vbt_defs.h
> index 93f5c9d204d6..09cd37fb0b1c 100644
> --- a/drivers/gpu/drm/i915/display/intel_vbt_defs.h
> +++ b/drivers/gpu/drm/i915/display/intel_vbt_defs.h
> @@ -481,13 +481,13 @@ struct psr_table {
>  	/* TP wake up time in multiple of 100 */
>  	u16 tp1_wakeup_time;
>  	u16 tp2_tp3_wakeup_time;
> -
> -	/* PSR2 TP2/TP3 wakeup time for 16 panels */
> -	u32 psr2_tp2_tp3_wakeup_time;
>  } __packed;
>  
>  struct bdb_psr {
>  	struct psr_table psr_table[16];
> +
> +	/* PSR2 TP2/TP3 wakeup time for 16 panels */
> +	u32 psr2_tp2_tp3_wakeup_time;
>  } __packed;
>  
>  /*