[Intel-gfx] [RFC v1 1/6] drm/edid: make a number of functions, parameters and variables const

Ville Syrjälä ville.syrjala at linux.intel.com
Wed Mar 10 18:54:38 UTC 2021


On Tue, Mar 09, 2021 at 03:54:09PM +0200, Jani Nikula wrote:
> If there's no need to change it, it should be const. There's more to be
> done, but start off with changes that make follow-up work easier. No
> functional changes.
> 
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>

const is good.

Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

> ---
>  drivers/gpu/drm/drm_edid.c  | 58 ++++++++++++++++++-------------------
>  include/drm/drm_displayid.h |  4 +--
>  2 files changed, 31 insertions(+), 31 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index c2bbe7bee7b6..d510b827a1f8 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -1585,7 +1585,7 @@ module_param_named(edid_fixup, edid_fixup, int, 0400);
>  MODULE_PARM_DESC(edid_fixup,
>  		 "Minimum number of valid EDID header bytes (0-8, default 6)");
>  
> -static int validate_displayid(u8 *displayid, int length, int idx);
> +static int validate_displayid(const u8 *displayid, int length, int idx);
>  
>  static int drm_edid_block_checksum(const u8 *raw_edid)
>  {
> @@ -3241,10 +3241,10 @@ add_detailed_modes(struct drm_connector *connector, struct edid *edid,
>  /*
>   * Search EDID for CEA extension block.
>   */
> -static u8 *drm_find_edid_extension(const struct edid *edid,
> -				   int ext_id, int *ext_index)
> +static const u8 *drm_find_edid_extension(const struct edid *edid,
> +					 int ext_id, int *ext_index)
>  {
> -	u8 *edid_ext = NULL;
> +	const u8 *edid_ext = NULL;
>  	int i;
>  
>  	/* No EDID or EDID extensions */
> @@ -3253,7 +3253,7 @@ static u8 *drm_find_edid_extension(const struct edid *edid,
>  
>  	/* Find CEA extension */
>  	for (i = *ext_index; i < edid->extensions; i++) {
> -		edid_ext = (u8 *)edid + EDID_LENGTH * (i + 1);
> +		edid_ext = (const u8 *)edid + EDID_LENGTH * (i + 1);
>  		if (edid_ext[0] == ext_id)
>  			break;
>  	}
> @@ -3267,12 +3267,12 @@ static u8 *drm_find_edid_extension(const struct edid *edid,
>  }
>  
>  
> -static u8 *drm_find_displayid_extension(const struct edid *edid,
> -					int *length, int *idx,
> -					int *ext_index)
> +static const u8 *drm_find_displayid_extension(const struct edid *edid,
> +					      int *length, int *idx,
> +					      int *ext_index)
>  {
> -	u8 *displayid = drm_find_edid_extension(edid, DISPLAYID_EXT, ext_index);
> -	struct displayid_hdr *base;
> +	const u8 *displayid = drm_find_edid_extension(edid, DISPLAYID_EXT, ext_index);
> +	const struct displayid_hdr *base;
>  	int ret;
>  
>  	if (!displayid)
> @@ -3286,18 +3286,18 @@ static u8 *drm_find_displayid_extension(const struct edid *edid,
>  	if (ret)
>  		return NULL;
>  
> -	base = (struct displayid_hdr *)&displayid[*idx];
> +	base = (const struct displayid_hdr *)&displayid[*idx];
>  	*length = *idx + sizeof(*base) + base->bytes;
>  
>  	return displayid;
>  }
>  
> -static u8 *drm_find_cea_extension(const struct edid *edid)
> +static const u8 *drm_find_cea_extension(const struct edid *edid)
>  {
>  	int length, idx;
> -	struct displayid_block *block;
> -	u8 *cea;
> -	u8 *displayid;
> +	const struct displayid_block *block;
> +	const u8 *cea;
> +	const u8 *displayid;
>  	int ext_index;
>  
>  	/* Look for a top level CEA extension block */
> @@ -3318,7 +3318,7 @@ static u8 *drm_find_cea_extension(const struct edid *edid)
>  		idx += sizeof(struct displayid_hdr);
>  		for_each_displayid_db(displayid, block, idx, length) {
>  			if (block->tag == DATA_BLOCK_CTA)
> -				return (u8 *)block;
> +				return (const u8 *)block;
>  		}
>  	}
>  
> @@ -4503,8 +4503,8 @@ static void clear_eld(struct drm_connector *connector)
>  static void drm_edid_to_eld(struct drm_connector *connector, struct edid *edid)
>  {
>  	uint8_t *eld = connector->eld;
> -	u8 *cea;
> -	u8 *db;
> +	const u8 *cea;
> +	const u8 *db;
>  	int total_sad_count = 0;
>  	int mnl;
>  	int dbl;
> @@ -4600,7 +4600,7 @@ int drm_edid_to_sad(struct edid *edid, struct cea_sad **sads)
>  {
>  	int count = 0;
>  	int i, start, end, dbl;
> -	u8 *cea;
> +	const u8 *cea;
>  
>  	cea = drm_find_cea_extension(edid);
>  	if (!cea) {
> @@ -4619,7 +4619,7 @@ int drm_edid_to_sad(struct edid *edid, struct cea_sad **sads)
>  	}
>  
>  	for_each_cea_db(cea, i, start, end) {
> -		u8 *db = &cea[i];
> +		const u8 *db = &cea[i];
>  
>  		if (cea_db_tag(db) == AUDIO_BLOCK) {
>  			int j;
> @@ -4631,7 +4631,7 @@ int drm_edid_to_sad(struct edid *edid, struct cea_sad **sads)
>  			if (!*sads)
>  				return -ENOMEM;
>  			for (j = 0; j < count; j++) {
> -				u8 *sad = &db[1 + j * 3];
> +				const u8 *sad = &db[1 + j * 3];
>  
>  				(*sads)[j].format = (sad[0] & 0x78) >> 3;
>  				(*sads)[j].channels = sad[0] & 0x7;
> @@ -4755,7 +4755,7 @@ EXPORT_SYMBOL(drm_av_sync_delay);
>   */
>  bool drm_detect_hdmi_monitor(struct edid *edid)
>  {
> -	u8 *edid_ext;
> +	const u8 *edid_ext;
>  	int i;
>  	int start_offset, end_offset;
>  
> @@ -4793,7 +4793,7 @@ EXPORT_SYMBOL(drm_detect_hdmi_monitor);
>   */
>  bool drm_detect_monitor_audio(struct edid *edid)
>  {
> -	u8 *edid_ext;
> +	const u8 *edid_ext;
>  	int i, j;
>  	bool has_audio = false;
>  	int start_offset, end_offset;
> @@ -5287,13 +5287,13 @@ u32 drm_add_display_info(struct drm_connector *connector, const struct edid *edi
>  	return quirks;
>  }
>  
> -static int validate_displayid(u8 *displayid, int length, int idx)
> +static int validate_displayid(const u8 *displayid, int length, int idx)
>  {
>  	int i, dispid_length;
>  	u8 csum = 0;
> -	struct displayid_hdr *base;
> +	const struct displayid_hdr *base;
>  
> -	base = (struct displayid_hdr *)&displayid[idx];
> +	base = (const struct displayid_hdr *)&displayid[idx];
>  
>  	DRM_DEBUG_KMS("base revision 0x%x, length %d, %d %d\n",
>  		      base->rev, base->bytes, base->prod_id, base->ext_count);
> @@ -5359,7 +5359,7 @@ static struct drm_display_mode *drm_mode_displayid_detailed(struct drm_device *d
>  }
>  
>  static int add_displayid_detailed_1_modes(struct drm_connector *connector,
> -					  struct displayid_block *block)
> +					  const struct displayid_block *block)
>  {
>  	struct displayid_detailed_timing_block *det = (struct displayid_detailed_timing_block *)block;
>  	int i;
> @@ -5387,9 +5387,9 @@ static int add_displayid_detailed_1_modes(struct drm_connector *connector,
>  static int add_displayid_detailed_modes(struct drm_connector *connector,
>  					struct edid *edid)
>  {
> -	u8 *displayid;
> +	const u8 *displayid;
>  	int length, idx;
> -	struct displayid_block *block;
> +	const struct displayid_block *block;
>  	int num_modes = 0;
>  	int ext_index = 0;
>  
> diff --git a/include/drm/drm_displayid.h b/include/drm/drm_displayid.h
> index 77941efb5426..f141c0eff083 100644
> --- a/include/drm/drm_displayid.h
> +++ b/include/drm/drm_displayid.h
> @@ -93,11 +93,11 @@ struct displayid_detailed_timing_block {
>  };
>  
>  #define for_each_displayid_db(displayid, block, idx, length) \
> -	for ((block) = (struct displayid_block *)&(displayid)[idx]; \
> +	for ((block) = (const struct displayid_block *)&(displayid)[idx]; \
>  	     (idx) + sizeof(struct displayid_block) <= (length) && \
>  	     (idx) + sizeof(struct displayid_block) + (block)->num_bytes <= (length) && \
>  	     (block)->num_bytes > 0; \
>  	     (idx) += sizeof(struct displayid_block) + (block)->num_bytes, \
> -	     (block) = (struct displayid_block *)&(displayid)[idx])
> +	     (block) = (const struct displayid_block *)&(displayid)[idx])
>  
>  #endif
> -- 
> 2.20.1
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Ville Syrjälä
Intel


More information about the Intel-gfx mailing list