[RFC,5/6] drm/msm/dsi: Flip greater-than check for slice_count and slice_per_intf

Message ID 20221213232207.113607-6-marijn.suijten@somainline.org
State New
Headers
Series drm/msm: DSC Electric Boogaloo for sm8[12]50 |

Commit Message

Marijn Suijten Dec. 13, 2022, 11:22 p.m. UTC
  According to downstream /and the comment copied from it/ this comparison
should be the other way around.  In other words, when the panel driver
requests to use more slices per packet than what could be sent over this
interface, it is bumped down to only use a single slice per packet (and
strangely not the number of slices that could fit on the interface).

Fixes: 08802f515c3c ("drm/msm/dsi: Add support for DSC configuration")
---
 drivers/gpu/drm/msm/dsi/dsi_host.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
  

Comments

Konrad Dybcio Dec. 14, 2022, 12:02 a.m. UTC | #1
On 14.12.2022 00:22, Marijn Suijten wrote:
> According to downstream /and the comment copied from it/ this comparison
> should be the other way around.  In other words, when the panel driver
> requests to use more slices per packet than what could be sent over this
> interface, it is bumped down to only use a single slice per packet (and
> strangely not the number of slices that could fit on the interface).
> 
> Fixes: 08802f515c3c ("drm/msm/dsi: Add support for DSC configuration")
> ---
Missing s-o-b

>  drivers/gpu/drm/msm/dsi/dsi_host.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
> index 0686c35a6fd4..9bdfa0864cdf 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi_host.c
> +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
> @@ -855,11 +855,11 @@ static void dsi_update_dsc_timing(struct msm_dsi_host *msm_host, bool is_cmd_mod
>  	 */
>  	slice_per_intf = DIV_ROUND_UP(hdisplay, dsc->slice_width);
>  
> -	/* If slice_per_pkt is greater than slice_per_intf
> +	/* If slice_count is greater than slice_per_intf
>  	 * then default to 1. This can happen during partial
>  	 * update.
>  	 */
> -	if (slice_per_intf > dsc->slice_count)
> +	if (dsc->slice_count > slice_per_intf)
>  		dsc->slice_count = 1;
>  
>  	total_bytes_per_intf = dsc->slice_chunk_size * slice_per_intf;
  
Marijn Suijten Dec. 14, 2022, 8:38 a.m. UTC | #2
On 2022-12-14 01:02:14, Konrad Dybcio wrote:
> 
> 
> On 14.12.2022 00:22, Marijn Suijten wrote:
> > According to downstream /and the comment copied from it/ this comparison
> > should be the other way around.  In other words, when the panel driver
> > requests to use more slices per packet than what could be sent over this
> > interface, it is bumped down to only use a single slice per packet (and
> > strangely not the number of slices that could fit on the interface).
> > 
> > Fixes: 08802f515c3c ("drm/msm/dsi: Add support for DSC configuration")

Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>

> > ---
> Missing s-o-b

Thanks for catching, checkpatch would've pointed this out (in addition
to a typo in the cover letter) if I had ran it.

> >  drivers/gpu/drm/msm/dsi/dsi_host.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
> > index 0686c35a6fd4..9bdfa0864cdf 100644
> > --- a/drivers/gpu/drm/msm/dsi/dsi_host.c
> > +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
> > @@ -855,11 +855,11 @@ static void dsi_update_dsc_timing(struct msm_dsi_host *msm_host, bool is_cmd_mod
> >  	 */
> >  	slice_per_intf = DIV_ROUND_UP(hdisplay, dsc->slice_width);
> >  
> > -	/* If slice_per_pkt is greater than slice_per_intf
> > +	/* If slice_count is greater than slice_per_intf
> >  	 * then default to 1. This can happen during partial
> >  	 * update.
> >  	 */
> > -	if (slice_per_intf > dsc->slice_count)
> > +	if (dsc->slice_count > slice_per_intf)
> >  		dsc->slice_count = 1;
> >  
> >  	total_bytes_per_intf = dsc->slice_chunk_size * slice_per_intf;
  
Dmitry Baryshkov Dec. 14, 2022, 6:53 p.m. UTC | #3
On 14/12/2022 01:22, Marijn Suijten wrote:
> According to downstream /and the comment copied from it/ this comparison
> should be the other way around.  In other words, when the panel driver
> requests to use more slices per packet than what could be sent over this
> interface, it is bumped down to only use a single slice per packet (and
> strangely not the number of slices that could fit on the interface).
> 
> Fixes: 08802f515c3c ("drm/msm/dsi: Add support for DSC configuration")
> ---
>   drivers/gpu/drm/msm/dsi/dsi_host.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)

With SoB in place:
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
  
Abhinav Kumar Dec. 17, 2022, 12:31 a.m. UTC | #4
On 12/13/2022 3:22 PM, Marijn Suijten wrote:
> According to downstream /and the comment copied from it/ this comparison
> should be the other way around.  In other words, when the panel driver
> requests to use more slices per packet than what could be sent over this
> interface, it is bumped down to only use a single slice per packet (and
> strangely not the number of slices that could fit on the interface).
> 
> Fixes: 08802f515c3c ("drm/msm/dsi: Add support for DSC configuration")

Like others have said, with SOB,
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
> ---
>   drivers/gpu/drm/msm/dsi/dsi_host.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
> index 0686c35a6fd4..9bdfa0864cdf 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi_host.c
> +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
> @@ -855,11 +855,11 @@ static void dsi_update_dsc_timing(struct msm_dsi_host *msm_host, bool is_cmd_mod
>   	 */
>   	slice_per_intf = DIV_ROUND_UP(hdisplay, dsc->slice_width);
>   
> -	/* If slice_per_pkt is greater than slice_per_intf
> +	/* If slice_count is greater than slice_per_intf
>   	 * then default to 1. This can happen during partial
>   	 * update.
>   	 */
> -	if (slice_per_intf > dsc->slice_count)
> +	if (dsc->slice_count > slice_per_intf)
>   		dsc->slice_count = 1;
>   
>   	total_bytes_per_intf = dsc->slice_chunk_size * slice_per_intf;
  

Patch

diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
index 0686c35a6fd4..9bdfa0864cdf 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_host.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
@@ -855,11 +855,11 @@  static void dsi_update_dsc_timing(struct msm_dsi_host *msm_host, bool is_cmd_mod
 	 */
 	slice_per_intf = DIV_ROUND_UP(hdisplay, dsc->slice_width);
 
-	/* If slice_per_pkt is greater than slice_per_intf
+	/* If slice_count is greater than slice_per_intf
 	 * then default to 1. This can happen during partial
 	 * update.
 	 */
-	if (slice_per_intf > dsc->slice_count)
+	if (dsc->slice_count > slice_per_intf)
 		dsc->slice_count = 1;
 
 	total_bytes_per_intf = dsc->slice_chunk_size * slice_per_intf;