On Sat, 08 Feb 2025, Egor Vorontsov <sdoregor@xxxxxxxx> wrote: > Some newer high refresh rate consumer monitors (including those by Samsung) > make use of DisplayID 2.1 timing blocks in their EDID data, notably for > their highest refresh rate modes. Such modes won't be available as of now. > > Implement partial support for such blocks in order to enable native > support of HRR modes of most such monitors for users without having to rely > on EDID patching/override (or need thereof). Thanks for the patch. It appears to do what's desired, but please find quite a bit of comments inline. > Link: https://gitlab.freedesktop.org/drm/misc/kernel/-/issues/55 I think "Closes:" is what we want. > Suggested-by: Maximilian Boße <max@xxxxxxxx> > Signed-off-by: Egor Vorontsov <sdoregor@xxxxxxxx> > > --- > > The formatting was taken from the neighboring code for consistency, > thus some warnings. Sometimes it's good to follow the surrounding code, but let's not duplicate existing mistakes. ;) > > [Resent due to some Spamhaus issues that are now resolved.] > > drivers/gpu/drm/drm_displayid_internal.h | 13 +++++ > drivers/gpu/drm/drm_edid.c | 61 ++++++++++++++++++++++++ > 2 files changed, 74 insertions(+) > > diff --git a/drivers/gpu/drm/drm_displayid_internal.h b/drivers/gpu/drm/drm_displayid_internal.h > index aee1b86a73c1..a75d0f637b72 100644 > --- a/drivers/gpu/drm/drm_displayid_internal.h > +++ b/drivers/gpu/drm/drm_displayid_internal.h > @@ -66,6 +66,7 @@ struct drm_edid; > #define DATA_BLOCK_2_STEREO_DISPLAY_INTERFACE 0x27 > #define DATA_BLOCK_2_TILED_DISPLAY_TOPOLOGY 0x28 > #define DATA_BLOCK_2_CONTAINER_ID 0x29 > +#define DATA_BLOCK_2_TYPE_10_FORMULA_TIMING 0x2a > #define DATA_BLOCK_2_VENDOR_SPECIFIC 0x7e > #define DATA_BLOCK_2_CTA_DISPLAY_ID 0x81 > > @@ -129,6 +130,18 @@ struct displayid_detailed_timing_block { > struct displayid_detailed_timings_1 timings[]; > }; > > +struct displayid_formula_timings_9 { > + u8 flags; > + u8 hactive[2]; > + u8 vactive[2]; Regardless of what was done in struct displayid_detailed_timings_1, I'd go for defining these as: __be16 hactive; __be16 vactive; and using be16_to_cpu() instead of hand-rolling it. > + u8 refresh; Nitpick, I'd go for vrefresh. > +} __packed; > + > +struct displayid_formula_timing_block { > + struct displayid_block base; > + struct displayid_formula_timings_9 timings[]; > +}; I know it's lacking in struct displayid_detailed_timing_block, but I'd add __packed here too. > + > #define DISPLAYID_VESA_MSO_OVERLAP GENMASK(3, 0) > #define DISPLAYID_VESA_MSO_MODE GENMASK(6, 5) > > diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c > index 13bc4c290b17..8a4dec1d781c 100644 > --- a/drivers/gpu/drm/drm_edid.c > +++ b/drivers/gpu/drm/drm_edid.c > @@ -6833,6 +6833,64 @@ static int add_displayid_detailed_1_modes(struct drm_connector *connector, > return num_modes; > } > > +static struct drm_display_mode *drm_mode_displayid_formula(struct drm_device *dev, > + struct displayid_formula_timings_9 *timings, const > + bool type_10) > +{ > + struct drm_display_mode *mode; > + unsigned hactive = (timings->hactive[0] | timings->hactive[1] << 8) + 1; > + unsigned vactive = (timings->vactive[0] | timings->vactive[1] << 8) + 1; u16 hactive = be16_to_cpu(timings->hactive) + 1; etc. > + u8 rb = timings->flags & 0b111; I'd call this formula or algorithm instead of just rb. Please avoid 0b, it's very rarely used. Just 0x7. Or we could start defining macros for these in drm_displayid_internal.h... Please add a blank line between declarations and code here. > + /* TODO: support RB-v2 & RB-v3 */ > + if (rb > 1) > + return NULL; > + > + mode = drm_cvt_mode(dev, hactive, vactive, timings->refresh, rb == 1, false, false); Refresh rate is -1 in the data block, so this needs timings->refresh + 1. > + if (!mode) > + return NULL; > + > + /* TODO: interpret S3D flags */ More important is TODO for fractional refresh rate indicated by bit 4 of flags. > + > + mode->type = DRM_MODE_TYPE_DRIVER; > + > + if (timings->flags & 0x80) > + mode->type |= DRM_MODE_TYPE_PREFERRED; There's no such thing? > + drm_mode_set_name(mode); > + > + return mode; > +} > + > +static int add_displayid_formula_modes(struct drm_connector *connector, > + const struct displayid_block *block) > +{ > + struct displayid_formula_timing_block *fb = (struct displayid_formula_timing_block *)block; Please avoid fb as the name for this. Everyone's going to go all "framebuffer", wtf, backtrack, oh, "formula block". ;) This should also be a const pointer. (I know, the detailed modes one isn't. Let's not duplicate mistakes from there.) > + int num_timings; > + struct drm_display_mode *newmode; > + int num_modes = 0; > + bool type_10 = block->tag == DATA_BLOCK_2_TYPE_10_FORMULA_TIMING; > + u8 timing_size = 6 + ((fb->base.rev & 0x70) >> 4); I'd go for int timing_size. Blank line here. > + /* extended blocks are not supported yet */ > + if (timing_size != 6) > + return 0; > + > + if (block->num_bytes % timing_size) > + return 0; > + > + num_timings = block->num_bytes / timing_size; > + for (int i = 0; i < num_timings; i++) { > + struct displayid_formula_timings_9 *timings = \ const. Please don't use \ line continuations, it's not necessary. > + (struct displayid_formula_timings_9 *)&((u8 *)fb->timings)[i * timing_size]; Since we only support the one size for now, and that size is fixed in struct displayid_formula_timings_9, there's no need to do all this hackery. Just formula->timings[i]. Whoever fixes this for size 7 might have a better idea how to handle the size anyway. > + > + newmode = drm_mode_displayid_formula(connector->dev, timings, type_10); > + if (!newmode) > + continue; > + > + drm_mode_probed_add(connector, newmode); > + num_modes++; > + } > + return num_modes; > +} > + > static int add_displayid_detailed_modes(struct drm_connector *connector, > const struct drm_edid *drm_edid) > { > @@ -6845,6 +6903,9 @@ static int add_displayid_detailed_modes(struct drm_connector *connector, > if (block->tag == DATA_BLOCK_TYPE_1_DETAILED_TIMING || > block->tag == DATA_BLOCK_2_TYPE_7_DETAILED_TIMING) > num_modes += add_displayid_detailed_1_modes(connector, block); > + else if (block->tag == DATA_BLOCK_2_TYPE_9_FORMULA_TIMING || > + block->tag == DATA_BLOCK_2_TYPE_10_FORMULA_TIMING) > + num_modes += add_displayid_formula_modes(connector, block); > } > displayid_iter_end(&iter); -- Jani Nikula, Intel
