| Message ID | 20230821160004.2821445-3-mitulkumar.ajitkumar.golani@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Get optimal audio frequency and channels | expand |
> Subject: [Intel-gfx] [PATCH 2/3] drm: Add Wrapper Functions for ELD SAD > Extraction > > Add wrapper functions to facilitate extracting Short Audio Descriptor (SAD) > information from EDID-Like Data (ELD) pointers with different constness > requirements. > > 1. `drm_eld_sad`: This function returns a constant `uint8_t` pointer and wraps > the main extraction function, allowing access to SAD information while > maintaining const correctness. > > 2. `drm_extract_sad_from_eld`: This function returns a mutable `uint8_t` > pointer and implements the core logic for extracting SAD from the provided ELD > pointer. It performs version and maximum channel checks to ensure proper > extraction. > > These wrapper functions provide flexibility to the codebase, allowing users to > access SAD information while adhering to const correctness when needed and > modifying the pointer when required. > > Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani@intel.com> This should also be floated in drm-devel mailing list. > --- > include/drm/drm_edid.h | 15 ++++++++++----- > 1 file changed, 10 insertions(+), 5 deletions(-) > > diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h index > 48e93f909ef6..626bc0d542eb 100644 > --- a/include/drm/drm_edid.h > +++ b/include/drm/drm_edid.h > @@ -418,11 +418,7 @@ static inline int drm_eld_mnl(const uint8_t *eld) > return (eld[DRM_ELD_CEA_EDID_VER_MNL] & > DRM_ELD_MNL_MASK) >> DRM_ELD_MNL_SHIFT; } > > -/** > - * drm_eld_sad - Get ELD SAD structures. > - * @eld: pointer to an eld memory structure with sad_count set > - */ > -static inline const uint8_t *drm_eld_sad(const uint8_t *eld) > +static uint8_t *drm_extract_sad_from_eld(uint8_t *eld) > { > unsigned int ver, mnl; > > @@ -437,6 +433,15 @@ static inline const uint8_t *drm_eld_sad(const uint8_t > *eld) > return eld + DRM_ELD_CEA_SAD(mnl, 0); > } > > +/** > + * drm_eld_sad - Get ELD SAD structures. > + * @eld: pointer to an eld memory structure with sad_count set */ > +static inline const uint8_t *drm_eld_sad(const uint8_t *eld) { > + return drm_extract_sad_from_eld((uint8_t *)eld); } > + Not sure about the wrapper here the point of the const variable here was we do not want the eld to be changed but adding a wrapper seems to make it irrelevant Also why do you want to change pointer data that is a const. Regards, Suraj Kandpal > /** > * drm_eld_sad_count - Get ELD SAD count. > * @eld: pointer to an eld memory structure with sad_count set > -- > 2.25.1
On Mon, 21 Aug 2023, Mitul Golani <mitulkumar.ajitkumar.golani@intel.com> wrote: > Add wrapper functions to facilitate extracting Short Audio > Descriptor (SAD) information from EDID-Like Data (ELD) pointers > with different constness requirements. > > 1. `drm_eld_sad`: This function returns a constant `uint8_t` > pointer and wraps the main extraction function, allowing access > to SAD information while maintaining const correctness. > > 2. `drm_extract_sad_from_eld`: This function returns a mutable > `uint8_t` pointer and implements the core logic for extracting > SAD from the provided ELD pointer. It performs version and > maximum channel checks to ensure proper extraction. > > These wrapper functions provide flexibility to the codebase, > allowing users to access SAD information while adhering to > const correctness when needed and modifying the pointer when > required. I've considered this, and in the end I think it's better to *not* make it easier for drivers to modify the ELD buffer directly. To that end, I wrote some helpers to modify the SADs using the existing struct cea_sad abstraction [1]. Please have a look. It should make your changes better focus on what you need to do here, instead of getting distracted with ELD parsing details. BR, Jani. [1] https://patchwork.freedesktop.org/series/123384/ > > Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani@intel.com> > --- > include/drm/drm_edid.h | 15 ++++++++++----- > 1 file changed, 10 insertions(+), 5 deletions(-) > > diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h > index 48e93f909ef6..626bc0d542eb 100644 > --- a/include/drm/drm_edid.h > +++ b/include/drm/drm_edid.h > @@ -418,11 +418,7 @@ static inline int drm_eld_mnl(const uint8_t *eld) > return (eld[DRM_ELD_CEA_EDID_VER_MNL] & DRM_ELD_MNL_MASK) >> DRM_ELD_MNL_SHIFT; > } > > -/** > - * drm_eld_sad - Get ELD SAD structures. > - * @eld: pointer to an eld memory structure with sad_count set > - */ > -static inline const uint8_t *drm_eld_sad(const uint8_t *eld) > +static uint8_t *drm_extract_sad_from_eld(uint8_t *eld) > { > unsigned int ver, mnl; > > @@ -437,6 +433,15 @@ static inline const uint8_t *drm_eld_sad(const uint8_t *eld) > return eld + DRM_ELD_CEA_SAD(mnl, 0); > } > > +/** > + * drm_eld_sad - Get ELD SAD structures. > + * @eld: pointer to an eld memory structure with sad_count set > + */ > +static inline const uint8_t *drm_eld_sad(const uint8_t *eld) > +{ > + return drm_extract_sad_from_eld((uint8_t *)eld); > +} > + > /** > * drm_eld_sad_count - Get ELD SAD count. > * @eld: pointer to an eld memory structure with sad_count set
diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h index 48e93f909ef6..626bc0d542eb 100644 --- a/include/drm/drm_edid.h +++ b/include/drm/drm_edid.h @@ -418,11 +418,7 @@ static inline int drm_eld_mnl(const uint8_t *eld) return (eld[DRM_ELD_CEA_EDID_VER_MNL] & DRM_ELD_MNL_MASK) >> DRM_ELD_MNL_SHIFT; } -/** - * drm_eld_sad - Get ELD SAD structures. - * @eld: pointer to an eld memory structure with sad_count set - */ -static inline const uint8_t *drm_eld_sad(const uint8_t *eld) +static uint8_t *drm_extract_sad_from_eld(uint8_t *eld) { unsigned int ver, mnl; @@ -437,6 +433,15 @@ static inline const uint8_t *drm_eld_sad(const uint8_t *eld) return eld + DRM_ELD_CEA_SAD(mnl, 0); } +/** + * drm_eld_sad - Get ELD SAD structures. + * @eld: pointer to an eld memory structure with sad_count set + */ +static inline const uint8_t *drm_eld_sad(const uint8_t *eld) +{ + return drm_extract_sad_from_eld((uint8_t *)eld); +} + /** * drm_eld_sad_count - Get ELD SAD count. * @eld: pointer to an eld memory structure with sad_count set
Add wrapper functions to facilitate extracting Short Audio Descriptor (SAD) information from EDID-Like Data (ELD) pointers with different constness requirements. 1. `drm_eld_sad`: This function returns a constant `uint8_t` pointer and wraps the main extraction function, allowing access to SAD information while maintaining const correctness. 2. `drm_extract_sad_from_eld`: This function returns a mutable `uint8_t` pointer and implements the core logic for extracting SAD from the provided ELD pointer. It performs version and maximum channel checks to ensure proper extraction. These wrapper functions provide flexibility to the codebase, allowing users to access SAD information while adhering to const correctness when needed and modifying the pointer when required. Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani@intel.com> --- include/drm/drm_edid.h | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-)