RE: [PATCH 3/7] drm: adv7511: Add max_lane_freq variable to struct adv7511_chip_info

2023-08-29 Thread Biju Das
Hi Laurent,

> Subject: Re: [PATCH 3/7] drm: adv7511: Add max_lane_freq variable to struct
> adv7511_chip_info
> 
> Hi Biju,
> 
> Thank you for the patch.
> 
> On Sun, Aug 13, 2023 at 07:05:08PM +0100, Biju Das wrote:
> > The ADV7533 supports a maximum lane clock of 800MHz whereas it is
> > 891MHz for ADV7535.  Add max_lane_freq variable to struct
> > adv7511_chip_info to handle this difference.
> >
> > While at it, drop the unused local variable max_lane_freq.
> >
> > Signed-off-by: Biju Das 
> > ---
> >  drivers/gpu/drm/bridge/adv7511/adv7511.h | 1 +
> >  drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 6 --
> >  drivers/gpu/drm/bridge/adv7511/adv7533.c | 5 +
> >  3 files changed, 6 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511.h
> > b/drivers/gpu/drm/bridge/adv7511/adv7511.h
> > index f8190442ffca..0e2c721a856f 100644
> > --- a/drivers/gpu/drm/bridge/adv7511/adv7511.h
> > +++ b/drivers/gpu/drm/bridge/adv7511/adv7511.h
> > @@ -336,6 +336,7 @@ enum adv7511_type {  struct adv7511_chip_info {
> > enum adv7511_type type;
> > unsigned long max_mode_clock;
> > +   unsigned long max_lane_freq;
> 
> Same comment as for patch 2/7, you could name the field max_lane_freq_khz.
> An unsigned int may be enough too if the calculation below doesn't
> overflow.

Agreed.

2 power 32 = 4,294,967,295 is large value compared to below calculation to 
trigger an overflow.

Cheers,
Biju

 
> 
> Reviewed-by: Laurent Pinchart 
> 
> >  };
> >
> >  struct adv7511 {
> > diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> > b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> > index 193b2d5bc7e6..29e087e6d721 100644
> > --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> > +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> > @@ -1372,12 +1372,14 @@ static const struct adv7511_chip_info
> > adv7511_chip_info = {
> >
> >  static const struct adv7511_chip_info adv7533_chip_info = {
> > .type = ADV7533,
> > -   .max_mode_clock = 8
> > +   .max_mode_clock = 8,
> > +   .max_lane_freq = 80,
> >  };
> >
> >  static const struct adv7511_chip_info adv7535_chip_info = {
> > .type = ADV7535,
> > -   .max_mode_clock = 148500
> > +   .max_mode_clock = 148500,
> > +   .max_lane_freq = 891000,
> >  };
> >
> >  static const struct i2c_device_id adv7511_i2c_ids[] = { diff --git
> > a/drivers/gpu/drm/bridge/adv7511/adv7533.c
> > b/drivers/gpu/drm/bridge/adv7511/adv7533.c
> > index e92b27e0afd1..c1e744d4f2b1 100644
> > --- a/drivers/gpu/drm/bridge/adv7511/adv7533.c
> > +++ b/drivers/gpu/drm/bridge/adv7511/adv7533.c
> > @@ -103,7 +103,6 @@ void adv7533_dsi_power_off(struct adv7511 *adv)
> > enum drm_mode_status adv7533_mode_valid(struct adv7511 *adv,
> > const struct drm_display_mode *mode)  {
> > -   unsigned long max_lane_freq;
> > struct mipi_dsi_device *dsi = adv->dsi;
> > u8 bpp = mipi_dsi_pixel_format_to_bpp(dsi->format);
> >
> > @@ -112,9 +111,7 @@ enum drm_mode_status adv7533_mode_valid(struct
> adv7511 *adv,
> > return MODE_CLOCK_HIGH;
> >
> > /* Check max clock for each lane */
> > -   max_lane_freq = (adv->info->type == ADV7533 ? 80 : 891000);
> > -
> > -   if (mode->clock * bpp > max_lane_freq * adv->num_dsi_lanes)
> > +   if (mode->clock * bpp > adv->info->max_lane_freq *
> > +adv->num_dsi_lanes)
> > return MODE_CLOCK_HIGH;
> >
> > return MODE_OK;
> 
> --
> Regards,
> 
> Laurent Pinchart


Re: [PATCH 3/7] drm: adv7511: Add max_lane_freq variable to struct adv7511_chip_info

2023-08-29 Thread Laurent Pinchart
Hi Biju,

Thank you for the patch.

On Sun, Aug 13, 2023 at 07:05:08PM +0100, Biju Das wrote:
> The ADV7533 supports a maximum lane clock of 800MHz whereas it is 891MHz
> for ADV7535.  Add max_lane_freq variable to struct adv7511_chip_info to
> handle this difference.
> 
> While at it, drop the unused local variable max_lane_freq.
> 
> Signed-off-by: Biju Das 
> ---
>  drivers/gpu/drm/bridge/adv7511/adv7511.h | 1 +
>  drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 6 --
>  drivers/gpu/drm/bridge/adv7511/adv7533.c | 5 +
>  3 files changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511.h 
> b/drivers/gpu/drm/bridge/adv7511/adv7511.h
> index f8190442ffca..0e2c721a856f 100644
> --- a/drivers/gpu/drm/bridge/adv7511/adv7511.h
> +++ b/drivers/gpu/drm/bridge/adv7511/adv7511.h
> @@ -336,6 +336,7 @@ enum adv7511_type {
>  struct adv7511_chip_info {
>   enum adv7511_type type;
>   unsigned long max_mode_clock;
> + unsigned long max_lane_freq;

Same comment as for patch 2/7, you could name the field
max_lane_freq_khz. An unsigned int may be enough too if the calculation
below doesn't overflow.

Reviewed-by: Laurent Pinchart 

>  };
>  
>  struct adv7511 {
> diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c 
> b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> index 193b2d5bc7e6..29e087e6d721 100644
> --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> @@ -1372,12 +1372,14 @@ static const struct adv7511_chip_info 
> adv7511_chip_info = {
>  
>  static const struct adv7511_chip_info adv7533_chip_info = {
>   .type = ADV7533,
> - .max_mode_clock = 8
> + .max_mode_clock = 8,
> + .max_lane_freq = 80,
>  };
>  
>  static const struct adv7511_chip_info adv7535_chip_info = {
>   .type = ADV7535,
> - .max_mode_clock = 148500
> + .max_mode_clock = 148500,
> + .max_lane_freq = 891000,
>  };
>  
>  static const struct i2c_device_id adv7511_i2c_ids[] = {
> diff --git a/drivers/gpu/drm/bridge/adv7511/adv7533.c 
> b/drivers/gpu/drm/bridge/adv7511/adv7533.c
> index e92b27e0afd1..c1e744d4f2b1 100644
> --- a/drivers/gpu/drm/bridge/adv7511/adv7533.c
> +++ b/drivers/gpu/drm/bridge/adv7511/adv7533.c
> @@ -103,7 +103,6 @@ void adv7533_dsi_power_off(struct adv7511 *adv)
>  enum drm_mode_status adv7533_mode_valid(struct adv7511 *adv,
>   const struct drm_display_mode *mode)
>  {
> - unsigned long max_lane_freq;
>   struct mipi_dsi_device *dsi = adv->dsi;
>   u8 bpp = mipi_dsi_pixel_format_to_bpp(dsi->format);
>  
> @@ -112,9 +111,7 @@ enum drm_mode_status adv7533_mode_valid(struct adv7511 
> *adv,
>   return MODE_CLOCK_HIGH;
>  
>   /* Check max clock for each lane */
> - max_lane_freq = (adv->info->type == ADV7533 ? 80 : 891000);
> -
> - if (mode->clock * bpp > max_lane_freq * adv->num_dsi_lanes)
> + if (mode->clock * bpp > adv->info->max_lane_freq * adv->num_dsi_lanes)
>   return MODE_CLOCK_HIGH;
>  
>   return MODE_OK;

-- 
Regards,

Laurent Pinchart