[PATCH v2] drm/edid: index CEA/HDMI mode tables using the VIC

Ville Syrjälä ville.syrjala at linux.intel.com
Fri Jan 8 03:30:29 PST 2016


On Fri, Jan 08, 2016 at 01:21:51PM +0200, Jani Nikula wrote:
> Add a dummy entry to CEA/HDMI mode tables so they can be indexed
> directly using the VIC, avoiding a +1/-1 dance here and there. This adds
> clarity to the error checking for various functions that return the VIC
> on success and zero on failure; we can now explicitly check for 0
> instead of just subtracting one from an unsigned type.
> 
> Also add drm_valid_cea_vic() and drm_valid_hdmi_vic() helpers for
> checking valid VICs.
> 
> v2: add drm_valid_cea_vic and drm_valid_hdmi_vic helpers (Ville)
>     use { } instead of { 0 } for initializing the dummy modes
> 
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Cc: Alex Deucher <alexander.deucher at amd.com>
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>

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

> ---
>  drivers/gpu/drm/drm_edid.c | 94 ++++++++++++++++++++++++++--------------------
>  1 file changed, 53 insertions(+), 41 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index c214f1246cb4..04cb4877fabd 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -637,8 +637,12 @@ static const struct minimode extra_modes[] = {
>  /*
>   * Probably taken from CEA-861 spec.
>   * This table is converted from xorg's hw/xfree86/modes/xf86EdidModes.c.
> + *
> + * Index using the VIC.
>   */
>  static const struct drm_display_mode edid_cea_modes[] = {
> +	/* 0 - dummy, VICs start at 1 */
> +	{ },
>  	/* 1 - 640x480 at 60Hz */
>  	{ DRM_MODE("640x480", DRM_MODE_TYPE_DRIVER, 25175, 640, 656,
>  		   752, 800, 0, 480, 490, 492, 525, 0,
> @@ -987,9 +991,11 @@ static const struct drm_display_mode edid_cea_modes[] = {
>  };
>  
>  /*
> - * HDMI 1.4 4k modes.
> + * HDMI 1.4 4k modes. Index using the VIC.
>   */
>  static const struct drm_display_mode edid_4k_modes[] = {
> +	/* 0 - dummy, VICs start at 1 */
> +	{ },
>  	/* 1 - 3840x2160 at 30Hz */
>  	{ DRM_MODE("3840x2160", DRM_MODE_TYPE_DRIVER, 297000,
>  		   3840, 4016, 4104, 4400, 0,
> @@ -2548,13 +2554,13 @@ cea_mode_alternate_clock(const struct drm_display_mode *cea_mode)
>  static u8 drm_match_cea_mode_clock_tolerance(const struct drm_display_mode *to_match,
>  					     unsigned int clock_tolerance)
>  {
> -	u8 mode;
> +	u8 vic;
>  
>  	if (!to_match->clock)
>  		return 0;
>  
> -	for (mode = 0; mode < ARRAY_SIZE(edid_cea_modes); mode++) {
> -		const struct drm_display_mode *cea_mode = &edid_cea_modes[mode];
> +	for (vic = 1; vic < ARRAY_SIZE(edid_cea_modes); vic++) {
> +		const struct drm_display_mode *cea_mode = &edid_cea_modes[vic];
>  		unsigned int clock1, clock2;
>  
>  		/* Check both 60Hz and 59.94Hz */
> @@ -2566,7 +2572,7 @@ static u8 drm_match_cea_mode_clock_tolerance(const struct drm_display_mode *to_m
>  			continue;
>  
>  		if (drm_mode_equal_no_clocks(to_match, cea_mode))
> -			return mode + 1;
> +			return vic;
>  	}
>  
>  	return 0;
> @@ -2581,13 +2587,13 @@ static u8 drm_match_cea_mode_clock_tolerance(const struct drm_display_mode *to_m
>   */
>  u8 drm_match_cea_mode(const struct drm_display_mode *to_match)
>  {
> -	u8 mode;
> +	u8 vic;
>  
>  	if (!to_match->clock)
>  		return 0;
>  
> -	for (mode = 0; mode < ARRAY_SIZE(edid_cea_modes); mode++) {
> -		const struct drm_display_mode *cea_mode = &edid_cea_modes[mode];
> +	for (vic = 1; vic < ARRAY_SIZE(edid_cea_modes); vic++) {
> +		const struct drm_display_mode *cea_mode = &edid_cea_modes[vic];
>  		unsigned int clock1, clock2;
>  
>  		/* Check both 60Hz and 59.94Hz */
> @@ -2597,12 +2603,17 @@ u8 drm_match_cea_mode(const struct drm_display_mode *to_match)
>  		if ((KHZ2PICOS(to_match->clock) == KHZ2PICOS(clock1) ||
>  		     KHZ2PICOS(to_match->clock) == KHZ2PICOS(clock2)) &&
>  		    drm_mode_equal_no_clocks_no_stereo(to_match, cea_mode))
> -			return mode + 1;
> +			return vic;
>  	}
>  	return 0;
>  }
>  EXPORT_SYMBOL(drm_match_cea_mode);
>  
> +static bool drm_valid_cea_vic(u8 vic)
> +{
> +	return vic > 0 && vic < ARRAY_SIZE(edid_cea_modes);
> +}
> +
>  /**
>   * drm_get_cea_aspect_ratio - get the picture aspect ratio corresponding to
>   * the input VIC from the CEA mode list
> @@ -2612,10 +2623,7 @@ EXPORT_SYMBOL(drm_match_cea_mode);
>   */
>  enum hdmi_picture_aspect drm_get_cea_aspect_ratio(const u8 video_code)
>  {
> -	/* return picture aspect ratio for video_code - 1 to access the
> -	 * right array element
> -	*/
> -	return edid_cea_modes[video_code-1].picture_aspect_ratio;
> +	return edid_cea_modes[video_code].picture_aspect_ratio;
>  }
>  EXPORT_SYMBOL(drm_get_cea_aspect_ratio);
>  
> @@ -2639,13 +2647,13 @@ hdmi_mode_alternate_clock(const struct drm_display_mode *hdmi_mode)
>  static u8 drm_match_hdmi_mode_clock_tolerance(const struct drm_display_mode *to_match,
>  					      unsigned int clock_tolerance)
>  {
> -	u8 mode;
> +	u8 vic;
>  
>  	if (!to_match->clock)
>  		return 0;
>  
> -	for (mode = 0; mode < ARRAY_SIZE(edid_4k_modes); mode++) {
> -		const struct drm_display_mode *hdmi_mode = &edid_4k_modes[mode];
> +	for (vic = 1; vic < ARRAY_SIZE(edid_4k_modes); vic++) {
> +		const struct drm_display_mode *hdmi_mode = &edid_4k_modes[vic];
>  		unsigned int clock1, clock2;
>  
>  		/* Make sure to also match alternate clocks */
> @@ -2657,7 +2665,7 @@ static u8 drm_match_hdmi_mode_clock_tolerance(const struct drm_display_mode *to_
>  			continue;
>  
>  		if (drm_mode_equal_no_clocks(to_match, hdmi_mode))
> -			return mode + 1;
> +			return vic;
>  	}
>  
>  	return 0;
> @@ -2673,13 +2681,13 @@ static u8 drm_match_hdmi_mode_clock_tolerance(const struct drm_display_mode *to_
>   */
>  static u8 drm_match_hdmi_mode(const struct drm_display_mode *to_match)
>  {
> -	u8 mode;
> +	u8 vic;
>  
>  	if (!to_match->clock)
>  		return 0;
>  
> -	for (mode = 0; mode < ARRAY_SIZE(edid_4k_modes); mode++) {
> -		const struct drm_display_mode *hdmi_mode = &edid_4k_modes[mode];
> +	for (vic = 1; vic < ARRAY_SIZE(edid_4k_modes); vic++) {
> +		const struct drm_display_mode *hdmi_mode = &edid_4k_modes[vic];
>  		unsigned int clock1, clock2;
>  
>  		/* Make sure to also match alternate clocks */
> @@ -2689,11 +2697,16 @@ static u8 drm_match_hdmi_mode(const struct drm_display_mode *to_match)
>  		if ((KHZ2PICOS(to_match->clock) == KHZ2PICOS(clock1) ||
>  		     KHZ2PICOS(to_match->clock) == KHZ2PICOS(clock2)) &&
>  		    drm_mode_equal_no_clocks_no_stereo(to_match, hdmi_mode))
> -			return mode + 1;
> +			return vic;
>  	}
>  	return 0;
>  }
>  
> +static bool drm_valid_hdmi_vic(u8 vic)
> +{
> +	return vic > 0 && vic < ARRAY_SIZE(edid_4k_modes);
> +}
> +
>  static int
>  add_alternate_cea_modes(struct drm_connector *connector, struct edid *edid)
>  {
> @@ -2713,16 +2726,16 @@ add_alternate_cea_modes(struct drm_connector *connector, struct edid *edid)
>  	list_for_each_entry(mode, &connector->probed_modes, head) {
>  		const struct drm_display_mode *cea_mode = NULL;
>  		struct drm_display_mode *newmode;
> -		u8 mode_idx = drm_match_cea_mode(mode) - 1;
> +		u8 vic = drm_match_cea_mode(mode);
>  		unsigned int clock1, clock2;
>  
> -		if (mode_idx < ARRAY_SIZE(edid_cea_modes)) {
> -			cea_mode = &edid_cea_modes[mode_idx];
> +		if (drm_valid_cea_vic(vic)) {
> +			cea_mode = &edid_cea_modes[vic];
>  			clock2 = cea_mode_alternate_clock(cea_mode);
>  		} else {
> -			mode_idx = drm_match_hdmi_mode(mode) - 1;
> -			if (mode_idx < ARRAY_SIZE(edid_4k_modes)) {
> -				cea_mode = &edid_4k_modes[mode_idx];
> +			vic = drm_match_hdmi_mode(mode);
> +			if (drm_valid_hdmi_vic(vic)) {
> +				cea_mode = &edid_4k_modes[vic];
>  				clock2 = hdmi_mode_alternate_clock(cea_mode);
>  			}
>  		}
> @@ -2773,17 +2786,17 @@ drm_display_mode_from_vic_index(struct drm_connector *connector,
>  {
>  	struct drm_device *dev = connector->dev;
>  	struct drm_display_mode *newmode;
> -	u8 cea_mode;
> +	u8 vic;
>  
>  	if (video_db == NULL || video_index >= video_len)
>  		return NULL;
>  
>  	/* CEA modes are numbered 1..127 */
> -	cea_mode = (video_db[video_index] & 127) - 1;
> -	if (cea_mode >= ARRAY_SIZE(edid_cea_modes))
> +	vic = (video_db[video_index] & 127);
> +	if (!drm_valid_cea_vic(vic))
>  		return NULL;
>  
> -	newmode = drm_mode_duplicate(dev, &edid_cea_modes[cea_mode]);
> +	newmode = drm_mode_duplicate(dev, &edid_cea_modes[vic]);
>  	if (!newmode)
>  		return NULL;
>  
> @@ -2878,8 +2891,7 @@ static int add_hdmi_mode(struct drm_connector *connector, u8 vic)
>  	struct drm_device *dev = connector->dev;
>  	struct drm_display_mode *newmode;
>  
> -	vic--; /* VICs start at 1 */
> -	if (vic >= ARRAY_SIZE(edid_4k_modes)) {
> +	if (!drm_valid_hdmi_vic(vic)) {
>  		DRM_ERROR("Unknown HDMI VIC: %d\n", vic);
>  		return 0;
>  	}
> @@ -3170,24 +3182,24 @@ static void fixup_detailed_cea_mode_clock(struct drm_display_mode *mode)
>  {
>  	const struct drm_display_mode *cea_mode;
>  	int clock1, clock2, clock;
> -	u8 mode_idx;
> +	u8 vic;
>  	const char *type;
>  
>  	/*
>  	 * allow 5kHz clock difference either way to account for
>  	 * the 10kHz clock resolution limit of detailed timings.
>  	 */
> -	mode_idx = drm_match_cea_mode_clock_tolerance(mode, 5) - 1;
> -	if (mode_idx < ARRAY_SIZE(edid_cea_modes)) {
> +	vic = drm_match_cea_mode_clock_tolerance(mode, 5);
> +	if (drm_valid_cea_vic(vic)) {
>  		type = "CEA";
> -		cea_mode = &edid_cea_modes[mode_idx];
> +		cea_mode = &edid_cea_modes[vic];
>  		clock1 = cea_mode->clock;
>  		clock2 = cea_mode_alternate_clock(cea_mode);
>  	} else {
> -		mode_idx = drm_match_hdmi_mode_clock_tolerance(mode, 5) - 1;
> -		if (mode_idx < ARRAY_SIZE(edid_4k_modes)) {
> +		vic = drm_match_hdmi_mode_clock_tolerance(mode, 5);
> +		if (drm_valid_hdmi_vic(vic)) {
>  			type = "HDMI";
> -			cea_mode = &edid_4k_modes[mode_idx];
> +			cea_mode = &edid_4k_modes[vic];
>  			clock1 = cea_mode->clock;
>  			clock2 = hdmi_mode_alternate_clock(cea_mode);
>  		} else {
> @@ -3205,7 +3217,7 @@ static void fixup_detailed_cea_mode_clock(struct drm_display_mode *mode)
>  		return;
>  
>  	DRM_DEBUG("detailed mode matches %s VIC %d, adjusting clock %d -> %d\n",
> -		  type, mode_idx + 1, mode->clock, clock);
> +		  type, vic, mode->clock, clock);
>  	mode->clock = clock;
>  }
>  
> -- 
> 2.1.4

-- 
Ville Syrjälä
Intel OTC


More information about the dri-devel mailing list