[RFC PATCH] drm/edid: index CEA/HDMI mode tables using the VIC
Ville Syrjälä
ville.syrjala at linux.intel.com
Wed Dec 2 04:24:22 PST 2015
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.
>
> 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
--
Ville Syrjälä
Intel OTC
More information about the dri-devel
mailing list