Re: [PATCH v3 2/2] drm/dp: drop the size parameter from drm_dp_vsc_sdp_pack()

[Rodrigo Vivi]

On Tue, Feb 20, 2024 at 11:53:47AM -0800, Abhinav Kumar wrote:
> Currently the size parameter of drm_dp_vsc_sdp_pack() is always
> the size of struct dp_sdp. Hence lets drop this parameter and
> use sizeof() directly.
> 
> Suggested-by: Dmitry Baryshkov 
> Signed-off-by: Abhinav Kumar 

it looks indeed an unecessary check.
you can convert my ack to a

Reviewed-by: Rodrigo Vivi 

and the ack to take this through drm-misc if needed

> ---
>  drivers/gpu/drm/display/drm_dp_helper.c | 8 ++--
>  drivers/gpu/drm/i915/display/intel_dp.c | 3 +--
>  include/drm/display/drm_dp_helper.h | 3 +--
>  3 files changed, 4 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/gpu/drm/display/drm_dp_helper.c 
> b/drivers/gpu/drm/display/drm_dp_helper.c
> index 6c91f400ecb1..10ee82e34de7 100644
> --- a/drivers/gpu/drm/display/drm_dp_helper.c
> +++ b/drivers/gpu/drm/display/drm_dp_helper.c
> @@ -2918,19 +2918,15 @@ EXPORT_SYMBOL(drm_dp_vsc_sdp_log);
>   * @vsc: vsc sdp initialized according to its purpose as defined in
>   *   table 2-118 - table 2-120 in DP 1.4a specification
>   * @sdp: valid handle to the generic dp_sdp which will be packed
> - * @size: valid size of the passed sdp handle
>   *
>   * Returns length of sdp on success and error code on failure
>   */
>  ssize_t drm_dp_vsc_sdp_pack(const struct drm_dp_vsc_sdp *vsc,
> - struct dp_sdp *sdp, size_t size)
> + struct dp_sdp *sdp)
>  {
>   size_t length = sizeof(struct dp_sdp);
>  
> - if (size < length)
> - return -ENOSPC;
> -
> - memset(sdp, 0, size);
> + memset(sdp, 0, sizeof(struct dp_sdp));
>  
>   /*
>* Prepare VSC Header for SU as per DP 1.4a spec, Table 2-119
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c 
> b/drivers/gpu/drm/i915/display/intel_dp.c
> index a9458df475e2..e13121dc3a03 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -4181,8 +4181,7 @@ static void intel_write_dp_sdp(struct intel_encoder 
> *encoder,
>  
>   switch (type) {
>   case DP_SDP_VSC:
> - len = drm_dp_vsc_sdp_pack(_state->infoframes.vsc, ,
> -   sizeof(sdp));
> + len = drm_dp_vsc_sdp_pack(_state->infoframes.vsc, );
>   break;
>   case HDMI_PACKET_TYPE_GAMUT_METADATA:
>   len = intel_dp_hdr_metadata_infoframe_sdp_pack(dev_priv,
> diff --git a/include/drm/display/drm_dp_helper.h 
> b/include/drm/display/drm_dp_helper.h
> index 8474504d4c88..1f41994796d3 100644
> --- a/include/drm/display/drm_dp_helper.h
> +++ b/include/drm/display/drm_dp_helper.h
> @@ -812,7 +812,6 @@ int drm_dp_bw_overhead(int lane_count, int hactive,
>  int bpp_x16, unsigned long flags);
>  int drm_dp_bw_channel_coding_efficiency(bool is_uhbr);
>  
> -ssize_t drm_dp_vsc_sdp_pack(const struct drm_dp_vsc_sdp *vsc,
> - struct dp_sdp *sdp, size_t size);
> +ssize_t drm_dp_vsc_sdp_pack(const struct drm_dp_vsc_sdp *vsc, struct dp_sdp 
> *sdp);
>  
>  #endif /* _DRM_DP_HELPER_H_ */
> -- 
> 2.34.1
> 

Re: [PATCH v3 2/2] drm/dp: drop the size parameter from drm_dp_vsc_sdp_pack()

[Rodrigo Vivi]

On Tue, Feb 20, 2024 at 11:53:47AM -0800, Abhinav Kumar wrote:
> Currently the size parameter of drm_dp_vsc_sdp_pack() is always
> the size of struct dp_sdp. Hence lets drop this parameter and
> use sizeof() directly.
> 
> Suggested-by: Dmitry Baryshkov 
> Signed-off-by: Abhinav Kumar 
> ---
>  drivers/gpu/drm/display/drm_dp_helper.c | 8 ++--
>  drivers/gpu/drm/i915/display/intel_dp.c | 3 +--

Acked-by: Rodrigo Vivi 

>  include/drm/display/drm_dp_helper.h | 3 +--
>  3 files changed, 4 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/gpu/drm/display/drm_dp_helper.c 
> b/drivers/gpu/drm/display/drm_dp_helper.c
> index 6c91f400ecb1..10ee82e34de7 100644
> --- a/drivers/gpu/drm/display/drm_dp_helper.c
> +++ b/drivers/gpu/drm/display/drm_dp_helper.c
> @@ -2918,19 +2918,15 @@ EXPORT_SYMBOL(drm_dp_vsc_sdp_log);
>   * @vsc: vsc sdp initialized according to its purpose as defined in
>   *   table 2-118 - table 2-120 in DP 1.4a specification
>   * @sdp: valid handle to the generic dp_sdp which will be packed
> - * @size: valid size of the passed sdp handle
>   *
>   * Returns length of sdp on success and error code on failure
>   */
>  ssize_t drm_dp_vsc_sdp_pack(const struct drm_dp_vsc_sdp *vsc,
> - struct dp_sdp *sdp, size_t size)
> + struct dp_sdp *sdp)
>  {
>   size_t length = sizeof(struct dp_sdp);
>  
> - if (size < length)
> - return -ENOSPC;
> -
> - memset(sdp, 0, size);
> + memset(sdp, 0, sizeof(struct dp_sdp));
>  
>   /*
>* Prepare VSC Header for SU as per DP 1.4a spec, Table 2-119
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c 
> b/drivers/gpu/drm/i915/display/intel_dp.c
> index a9458df475e2..e13121dc3a03 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -4181,8 +4181,7 @@ static void intel_write_dp_sdp(struct intel_encoder 
> *encoder,
>  
>   switch (type) {
>   case DP_SDP_VSC:
> - len = drm_dp_vsc_sdp_pack(_state->infoframes.vsc, ,
> -   sizeof(sdp));
> + len = drm_dp_vsc_sdp_pack(_state->infoframes.vsc, );
>   break;
>   case HDMI_PACKET_TYPE_GAMUT_METADATA:
>   len = intel_dp_hdr_metadata_infoframe_sdp_pack(dev_priv,
> diff --git a/include/drm/display/drm_dp_helper.h 
> b/include/drm/display/drm_dp_helper.h
> index 8474504d4c88..1f41994796d3 100644
> --- a/include/drm/display/drm_dp_helper.h
> +++ b/include/drm/display/drm_dp_helper.h
> @@ -812,7 +812,6 @@ int drm_dp_bw_overhead(int lane_count, int hactive,
>  int bpp_x16, unsigned long flags);
>  int drm_dp_bw_channel_coding_efficiency(bool is_uhbr);
>  
> -ssize_t drm_dp_vsc_sdp_pack(const struct drm_dp_vsc_sdp *vsc,
> - struct dp_sdp *sdp, size_t size);
> +ssize_t drm_dp_vsc_sdp_pack(const struct drm_dp_vsc_sdp *vsc, struct dp_sdp 
> *sdp);
>  
>  #endif /* _DRM_DP_HELPER_H_ */
> -- 
> 2.34.1
> 

Re: [PATCH v3 2/2] drm/dp: drop the size parameter from drm_dp_vsc_sdp_pack()

[Dmitry Baryshkov]

On Tue, 20 Feb 2024 at 21:54, Abhinav Kumar  wrote:
>
> Currently the size parameter of drm_dp_vsc_sdp_pack() is always
> the size of struct dp_sdp. Hence lets drop this parameter and
> use sizeof() directly.
>
> Suggested-by: Dmitry Baryshkov 
> Signed-off-by: Abhinav Kumar 
> ---
>  drivers/gpu/drm/display/drm_dp_helper.c | 8 ++--
>  drivers/gpu/drm/i915/display/intel_dp.c | 3 +--
>  include/drm/display/drm_dp_helper.h | 3 +--
>  3 files changed, 4 insertions(+), 10 deletions(-)

Thank you!

Acked-by: Dmitry Baryshkov 



-- 
With best wishes
Dmitry