[RFC PATCH] drm/edid: index CEA/HDMI mode tables using the VIC
Jani Nikula
jani.nikula at intel.com
Wed Dec 2 04:57:39 PST 2015
On Wed, 02 Dec 2015, Ville Syrjälä <ville.syrjala at linux.intel.com> wrote:
> On Wed, Dec 02, 2015 at 01:46:40PM +0200, Jani Nikula wrote:
>> On Tue, 01 Dec 2015, Ville Syrjälä <ville.syrjala at linux.intel.com> wrote:
>> > On Tue, Dec 01, 2015 at 05:16:54PM +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 now explicitly check for 0 instead of
>> >> just subtracting one from an unsigned type.
>> >>
>> >> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
>> >> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
>> >>
>> >> ---
>> >>
>> >> This is on top of
>> >>
>> >> commit 4c6bcf44549907cb50b67f98eb13717a4adc6b33
>> >> Author: Ville Syrjälä <ville.syrjala at linux.intel.com>
>> >> Date: Mon Nov 16 21:05:12 2015 +0200
>> >>
>> >> drm/edid: Make the detailed timing CEA/HDMI mode fixup accept up to 5kHz clock difference
>> >>
>> >> in drm-intel/topic/drm-misc
>> >> ---
>> >> drivers/gpu/drm/drm_edid.c | 84 ++++++++++++++++++++++++----------------------
>> >> 1 file changed, 43 insertions(+), 41 deletions(-)
>> >>
>> >> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
>> >> index c214f1246cb4..aea09eae407e 100644
>> >> --- a/drivers/gpu/drm/drm_edid.c
>> >> +++ b/drivers/gpu/drm/drm_edid.c
>> > <snip>
>> >> @@ -2713,16 +2716,16 @@ 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 (vic > 0 && vic < ARRAY_SIZE(edid_cea_modes)) {
>> >
>> > Maybe add some sort of vic_is_valid() helpers to avoid duplicating
>> > these in so many places?
>>
>> Any thoughts on how that should handle CEA vs. HDMI VICs, comparing
>> against ARRAY_SIZE(edid_cea_modes) and ARRAY_SIZE(edid_4k_modes)?
>
> I was thinking one function for each type, and yeah just
>
> return vic != 0 && vic < ARRAY_SIZE(whatever_modes);
>
> or something along those lines.
>
>>
>> Add versions of drm_match_*_mode*() that return struct drm_display_mode
>> * or NULL on errors?
>
> Some time ago I was readin the DP spec, and ended up sketching out
> some functions that might help deal with EDIDless DP branch devices.
> For that I cooked up a function to return a pointer to the appropriate
> CEA mode based on the vic (or NULL for bad vics). So I guess if you did
> something like that + take the already existing match function, you
> could wrap them in a neat package that returns the matching cea mode
> for whatever mode is passed in.
Mmmh, so how about just taking this patch as-is for now...?
BR,
Jani.
>
>>
>> BR,
>> Jani.
>>
>>
>> >
>> > Otherwise I like it.
>> >
>> >> + 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 (vic > 0 && vic < ARRAY_SIZE(edid_4k_modes)) {
>> >> + cea_mode = &edid_4k_modes[vic];
>> >> clock2 = hdmi_mode_alternate_clock(cea_mode);
>> >> }
>> >> }
>> >> @@ -2773,17 +2776,17 @@ 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 (vic == 0 || vic >= ARRAY_SIZE(edid_cea_modes))
>> >> 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 +2881,7 @@ 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 (vic == 0 || vic >= ARRAY_SIZE(edid_4k_modes)) {
>> >> DRM_ERROR("Unknown HDMI VIC: %d\n", vic);
>> >> return 0;
>> >> }
>> >> @@ -3170,24 +3172,24 @@ 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 (vic > 0 && vic < ARRAY_SIZE(edid_cea_modes)) {
>> >> 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 (vic > 0 && vic < ARRAY_SIZE(edid_4k_modes)) {
>> >> 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 +3207,7 @@ 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
>>
>> --
>> Jani Nikula, Intel Open Source Technology Center
--
Jani Nikula, Intel Open Source Technology Center
More information about the dri-devel
mailing list