On Thu, 16 Jan 2025, Alex Deucher <alexdeucher@xxxxxxxxx> wrote: > On Tue, Nov 5, 2024 at 9:14 PM Hamza Mahfooz <hamza.mahfooz@xxxxxxx> wrote: >> >> Video Format Data Blocks (VFDBs) contain the necessary information that >> needs to be fed to the Optimized Video Timings (OVT) Algorithm. >> Also, we require OVT support to cover modes that aren't supported by >> earlier standards (e.g. CVT). So, parse all of the relevant VFDB data >> and feed it to the OVT Algorithm, to extract all of the missing OVT >> modes. >> >> Cc: Ian Forbes <ian.forbes@xxxxxxxxxxxx> >> Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx> >> Suggested-by: Karol Herbst <kherbst@xxxxxxxxxx> >> Signed-off-by: Hamza Mahfooz <hamza.mahfooz@xxxxxxx> >> --- >> v3: move ovt stuff above add_cea_modes() and break up >> calculate_ovt_mode() to make it easier to read. >> >> v4: fix 32 bit build and constify read-only vars. >> >> v5: Implement suggestions from: >> https://lore.kernel.org/dri-devel/87plpbk92h.fsf@xxxxxxxxx/ >> and export drm_ovt_mode(). > > Any concerns with this patch? Can we land this? Has someone properly reviewed it against the specs? I've provided some comments to earlier versions, and I think the end result is better, but alas I haven't had the time to go through all the calculations etc. And someone definitely should do that before merging. BR, Jani. > > Alex > >> --- >> drivers/gpu/drm/drm_edid.c | 465 +++++++++++++++++++++++++++++++++++++ >> include/drm/drm_edid.h | 3 + >> 2 files changed, 468 insertions(+) >> >> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c >> index 855beafb76ff..e5e34397be00 100644 >> --- a/drivers/gpu/drm/drm_edid.c >> +++ b/drivers/gpu/drm/drm_edid.c >> @@ -31,6 +31,7 @@ >> #include <linux/bitfield.h> >> #include <linux/byteorder/generic.h> >> #include <linux/cec.h> >> +#include <linux/gcd.h> >> #include <linux/hdmi.h> >> #include <linux/i2c.h> >> #include <linux/kernel.h> >> @@ -741,6 +742,87 @@ static const struct minimode extra_modes[] = { >> { 2048, 1536, 60, 0 }, >> }; >> >> +struct cta_rid { >> + u16 hactive; >> + u16 vactive; >> + u8 hratio; >> + u8 vratio; >> +}; >> + >> +/* CTA-861-I Table 11 - Resolution Identification (RID) */ >> +static const struct cta_rid rids[] = { >> + [0] = { 0, 0, 0, 0 }, >> + [1] = { 1280, 720, 16, 9 }, >> + [2] = { 1280, 720, 64, 27 }, >> + [3] = { 1680, 720, 64, 27 }, >> + [4] = { 1920, 1080, 16, 9 }, >> + [5] = { 1920, 1080, 64, 27 }, >> + [6] = { 2560, 1080, 64, 27 }, >> + [7] = { 3840, 1080, 32, 9 }, >> + [8] = { 2560, 1440, 16, 9 }, >> + [9] = { 3440, 1440, 64, 27 }, >> + [10] = { 5120, 1440, 32, 9 }, >> + [11] = { 3840, 2160, 16, 9 }, >> + [12] = { 3840, 2160, 64, 27 }, >> + [13] = { 5120, 2160, 64, 27 }, >> + [14] = { 7680, 2160, 32, 9 }, >> + [15] = { 5120, 2880, 16, 9 }, >> + [16] = { 5120, 2880, 64, 27 }, >> + [17] = { 6880, 2880, 64, 27 }, >> + [18] = { 10240, 2880, 32, 9 }, >> + [19] = { 7680, 4320, 16, 9 }, >> + [20] = { 7680, 4320, 64, 27 }, >> + [21] = { 10240, 4320, 64, 27 }, >> + [22] = { 15360, 4320, 32, 9 }, >> + [23] = { 11520, 6480, 16, 9 }, >> + [24] = { 11520, 6480, 64, 27 }, >> + [25] = { 15360, 6480, 64, 27 }, >> + [26] = { 15360, 8640, 16, 9 }, >> + [27] = { 15360, 8640, 64, 27 }, >> + [28] = { 20480, 8640, 64, 27 }, >> +}; >> + >> +/* CTA-861-I Table 12 - AVI InfoFrame Video Format Frame Rate */ >> +static const u16 video_format_frame_rates[] = { >> + /* Frame Rate 0-7 */ >> + 0, 24, 25, 30, 48, 50, 60, 100, >> + /* Frame Rate 8-15 */ >> + 120, 144, 200, 240, 300, 360, 400, 480, >> +}; >> + >> +/* CTA-861-I Table 13 - RID To VIC Mapping */ >> +static const u8 rid_to_vic[][8] = { >> + [0] = {}, >> + [1] = { 60, 61, 62, 108, 19, 4, 41, 47 }, >> + [2] = { 65, 66, 67, 109, 68, 69, 70, 71 }, >> + [3] = { 79, 80, 81, 110, 82, 83, 84, 85 }, >> + [4] = { 32, 33, 34, 111, 31, 16, 64, 63 }, >> + [5] = { 72, 73, 74, 112, 75, 76, 77, 78 }, >> + [6] = { 86, 87, 88, 113, 89, 90, 91, 92 }, >> + [7] = {}, >> + [8] = {}, >> + [9] = {}, >> + [10] = {}, >> + [11] = { 93, 94, 95, 114, 96, 97, 117, 118 }, >> + [12] = { 103, 104, 105, 116, 106, 107, 119, 120 }, >> + [13] = { 121, 122, 123, 124, 125, 126, 127, 193 }, >> + [14] = {}, >> + [15] = {}, >> + [16] = {}, >> + [17] = {}, >> + [18] = {}, >> + [19] = { 194, 195, 196, 197, 198, 199, 200, 201 }, >> + [20] = { 202, 203, 204, 205, 206, 207, 208, 209 }, >> + [21] = { 210, 211, 212, 213, 214, 215, 216, 217 }, >> + [22] = {}, >> + [23] = {}, >> + [24] = {}, >> + [25] = {}, >> + [26] = {}, >> + [27] = {}, >> + [28] = {}, >> +}; >> + >> /* >> * From CEA/CTA-861 spec. >> * >> @@ -4131,6 +4213,7 @@ static int add_detailed_modes(struct drm_connector *connector, >> #define CTA_DB_VIDEO 2 >> #define CTA_DB_VENDOR 3 >> #define CTA_DB_SPEAKER 4 >> +#define CTA_DB_VIDEO_FORMAT 6 >> #define CTA_DB_EXTENDED_TAG 7 >> >> /* CTA-861-H Table 62 - CTA Extended Tag Codes */ >> @@ -4972,6 +5055,16 @@ struct cea_db { >> u8 data[]; >> } __packed; >> >> +struct cta_vfd { >> + u8 rid; >> + u8 fr_fact; >> + bool bfr50; >> + bool fr24; >> + bool bfr60; >> + bool fr144; >> + bool fr48; >> +}; >> + >> static int cea_db_tag(const struct cea_db *db) >> { >> return db->tag_length >> 5; >> @@ -5250,6 +5343,376 @@ static int edid_hfeeodb_extension_block_count(const struct edid *edid) >> return cta[4 + 2]; >> } >> >> +/* CTA-861 Video Format Descriptor (CTA VFD) */ >> +static void parse_cta_vfd(struct cta_vfd *vfd, const u8 *data, int vfd_len) >> +{ >> + vfd->rid = data[0] & 0x3f; >> + vfd->bfr50 = data[0] & 0x80; >> + vfd->fr24 = data[0] & 0x40; >> + vfd->bfr60 = vfd_len > 1 ? (data[1] & 0x80) : true; >> + vfd->fr144 = vfd_len > 1 ? (data[1] & 0x40) : false; >> + vfd->fr_fact = vfd_len > 1 ? (data[1] & 0x3f) : 0x3; >> + vfd->fr48 = vfd_len > 2 ? (data[2] & 0x1) : false; >> +} >> + >> +static bool vfd_has_fr(const struct cta_vfd *vfd, int rate) >> +{ >> + static const u8 factors[] = { >> + 1, 2, 4, 8, 12, 16 >> + }; >> + int factor = 0; >> + int i; >> + >> + switch (rate) { >> + case 24: >> + return vfd->fr24; >> + case 48: >> + return vfd->fr48; >> + case 144: >> + return vfd->fr144; >> + } >> + >> + if (!(rate % 25)) { >> + if (!vfd->bfr50) >> + return false; >> + >> + factor = rate / 25; >> + } else if (!(rate % 30)) { >> + if (!vfd->bfr60) >> + return false; >> + >> + factor = rate / 30; >> + } >> + >> + for (i = 0; i < ARRAY_SIZE(factors); i++) >> + if (factor == factors[i] && (vfd->fr_fact & (1 << i))) >> + return true; >> + >> + return false; >> +} >> + >> +#define OVT_PIXEL_CLOCK_GRANULARITY 1000 /* Hz */ >> +#define OVT_MIN_HTOTAL_GRANULARITY 8 /* pixels */ >> +#define OVT_MIN_VBLANK_DURATION 460000000 /* ps */ >> +#define OVT_MIN_VBLANK_LINES 20 >> +#define OVT_MIN_VSYNC_LEADING_EDGE 400 /* us */ >> +#define OVT_MIN_VSYNC_LE_LINES 14 >> +#define OVT_MIN_CLOCK_RATE_420 590000000 /* Hz */ >> +#define OVT_PIXEL_FACTOR_420 2 >> +#define OVT_MIN_HBLANK_444 80 /* pixels */ >> +#define OVT_MIN_HBLANK_420 128 /* pixels */ >> +#define OVT_MAX_CHUNK_RATE 650000000 /* Hz */ >> +#define OVT_AUDIO_PACKET_RATE 195000 /* Hz */ >> +#define OVT_AUDIO_PACKET_SIZE 32 >> +#define OVT_LINE_OVERHEAD 32 >> +#define OVT_HSYNC_WIDTH 32 >> +#define OVT_VSYNC_WIDTH 8 >> + >> +static u32 calculate_ovt_min_vtotal(const struct cta_rid *rid, u64 max_vrate, >> + u32 vtotal_granularity) >> +{ >> + u64 max_active_time; >> + u32 min_line_time; >> + u32 min_vblank; >> + u32 min_vtotal; >> + >> + /* step 2 */ >> + max_active_time = div64_u64(1000000000000, max_vrate) - >> + (u64)OVT_MIN_VBLANK_DURATION; >> + >> + min_line_time = div_u64(max_active_time, rid->vactive); >> + >> + min_vblank = max_t(u64, (u64)OVT_MIN_VBLANK_LINES, >> + DIV64_U64_ROUND_UP(OVT_MIN_VBLANK_DURATION, >> + min_line_time)); >> + >> + min_vtotal = rid->vactive + min_vblank; >> + >> + if (min_vtotal % vtotal_granularity) >> + min_vtotal += vtotal_granularity - (min_vtotal % >> + vtotal_granularity); >> + >> + return min_vtotal; >> +} >> + >> +static u32 calculate_ovt_min_htotal(const struct cta_rid *rid, >> + const u32 max_vrate, >> + const u32 min_vtotal, >> + u32 *min_hblank, >> + u32 *htotal_granularity) >> +{ >> + u32 max_audio_packets_per_line; >> + u32 htotal_granularity_chunk; >> + u64 min_pixel_clock_rate; >> + u32 min_line_rate; >> + u32 min_htotal; >> + >> + /* step 3 */ >> + min_line_rate = max_vrate * min_vtotal; >> + >> + max_audio_packets_per_line = DIV_ROUND_UP(OVT_AUDIO_PACKET_RATE, >> + min_line_rate); >> + >> + /* step 4 */ >> + *min_hblank = OVT_LINE_OVERHEAD + OVT_AUDIO_PACKET_SIZE * >> + max_audio_packets_per_line; >> + >> + min_htotal = rid->hactive + max(OVT_MIN_HBLANK_444, *min_hblank); >> + >> + min_pixel_clock_rate = max_vrate * min_htotal * min_vtotal; >> + >> + htotal_granularity_chunk = >> + roundup_pow_of_two(DIV64_U64_ROUND_UP(min_pixel_clock_rate, >> + OVT_MAX_CHUNK_RATE)); >> + >> + *htotal_granularity = max(OVT_MIN_HTOTAL_GRANULARITY, >> + htotal_granularity_chunk); >> + >> + if (min_htotal % *htotal_granularity) >> + min_htotal += *htotal_granularity - (min_htotal % >> + *htotal_granularity); >> + >> + return min_htotal; >> +} >> + >> +static u64 calculate_ovt_pixel_clock_rate(const struct cta_rid *rid, >> + const u32 max_vrate, >> + const u32 min_hblank, >> + u32 min_htotal, >> + u32 min_vtotal, >> + const u32 htotal_granularity, >> + const u32 vtotal_granularity, >> + u32 *htotal, u32 *vtotal) >> +{ >> + u32 resolution_granularity; >> + u64 pixel_clock_rate; >> + u64 min_resolution; >> + u64 rem; >> + u32 h; >> + u64 r; >> + u32 v; >> + >> + resolution_granularity = OVT_PIXEL_CLOCK_GRANULARITY / >> + gcd(OVT_PIXEL_CLOCK_GRANULARITY, max_vrate); >> + >> + do { >> + /* step 5 */ >> + min_resolution = 0; >> + v = min_vtotal; >> + >> + goto loop_end; >> + >> + while (!min_resolution || r <= min_resolution) { >> + goto inner_loop_end; >> + >> + while (rem || div64_u64(max_vrate * r, (h & ~(h - 1))) > >> + OVT_MAX_CHUNK_RATE) { >> + h += htotal_granularity; >> + r = (u64)h * (u64)v; >> +inner_loop_end: >> + div64_u64_rem(r, resolution_granularity, &rem); >> + } >> + >> + if (!min_resolution || r < min_resolution) { >> + *htotal = h; >> + *vtotal = v; >> + min_resolution = r; >> + } >> + >> + v += vtotal_granularity; >> + >> +loop_end: >> + h = min_htotal; >> + r = (u64)h * (u64)v; >> + } >> + >> + pixel_clock_rate = max_vrate * min_resolution; >> + >> + /* step 6 */ >> + min_htotal = rid->hactive + max(OVT_MIN_HBLANK_420, >> + OVT_PIXEL_FACTOR_420 * >> + min_hblank); >> + >> + } while (pixel_clock_rate >= OVT_MIN_CLOCK_RATE_420 && >> + *htotal < min_htotal); >> + >> + return pixel_clock_rate; >> +} >> + >> +static const struct cta_rid *find_rid(u8 rid) >> +{ >> + if (!rid || rid >= ARRAY_SIZE(rids)) >> + return NULL; >> + >> + return &rids[rid]; >> +} >> + >> +/* OVT Algorthim as specified in CTA-861-I */ >> +struct drm_display_mode *drm_ovt_mode(struct drm_device *dev, int r_id, >> + int vrefresh) >> +{ >> + const struct cta_rid *rid = find_rid(r_id); >> + struct drm_display_mode *mode; >> + u32 vtotal_granularity = 1; >> + u32 htotal_granularity; >> + u32 max_vrate = vrefresh; >> + u64 pixel_clock_rate; >> + u32 vsync_position; >> + u32 min_hblank; >> + u32 min_htotal; >> + u32 min_vtotal; >> + u32 htotal; >> + u32 vtotal; >> + >> + if (!rid) >> + return NULL; >> + >> + /* step 1 */ >> + switch (vrefresh) { >> + case 24: >> + case 25: >> + max_vrate = 30; >> + fallthrough; >> + case 30: >> + vtotal_granularity = 20; >> + break; >> + case 48: >> + case 50: >> + max_vrate = 60; >> + fallthrough; >> + case 60: >> + vtotal_granularity = 20; >> + break; >> + case 100: >> + max_vrate = 120; >> + fallthrough; >> + case 120: >> + vtotal_granularity = 5; >> + break; >> + case 200: >> + max_vrate = 240; >> + fallthrough; >> + case 240: >> + vtotal_granularity = 5; >> + break; >> + case 300: >> + max_vrate = 360; >> + fallthrough; >> + case 360: >> + vtotal_granularity = 5; >> + break; >> + case 400: >> + max_vrate = 480; >> + fallthrough; >> + case 480: >> + vtotal_granularity = 5; >> + break; >> + } >> + >> + min_vtotal = calculate_ovt_min_vtotal(rid, max_vrate, >> + vtotal_granularity); >> + >> + min_htotal = calculate_ovt_min_htotal(rid, max_vrate, min_vtotal, >> + &min_hblank, &htotal_granularity); >> + >> + pixel_clock_rate = calculate_ovt_pixel_clock_rate(rid, max_vrate, >> + min_hblank, >> + min_htotal, >> + min_vtotal, >> + htotal_granularity, >> + vtotal_granularity, >> + &htotal, &vtotal); >> + >> + /* step 7 */ >> + vtotal = vtotal * max_vrate / (u32)vrefresh; >> + >> + /* step 8 */ >> + vsync_position = max(OVT_MIN_VSYNC_LE_LINES, >> + DIV64_U64_ROUND_UP((u64)OVT_MIN_VSYNC_LE_LINES * >> + pixel_clock_rate, >> + (u64)htotal * (u64)1000000)); >> + >> + mode = drm_mode_create(dev); >> + >> + if (!mode) >> + return NULL; >> + >> + /* step 10 */ >> + mode->clock = div_u64(pixel_clock_rate, 1000); >> + mode->hdisplay = rid->hactive; >> + mode->hsync_start = htotal - OVT_HSYNC_WIDTH * 2; >> + mode->hsync_end = mode->hsync_start + OVT_HSYNC_WIDTH; >> + mode->htotal = htotal; >> + >> + mode->vdisplay = rid->vactive; >> + mode->vsync_start = vtotal - vsync_position; >> + mode->vsync_end = mode->vsync_start + OVT_VSYNC_WIDTH; >> + mode->vtotal = vtotal; >> + >> + return mode; >> +} >> + >> +static u8 find_vic(u8 rid, int rate_idx) >> +{ >> + if (video_format_frame_rates[rate_idx] > 120 || !find_rid(rid)) >> + return 0; >> + >> + return rid_to_vic[rid][rate_idx - 1]; >> +} >> + >> +/* CTA-861 Video Format Data Block (CTA VFDB) */ >> +static int add_modes_from_vfdb(struct drm_connector *connector, >> + const struct cea_db *db) >> +{ >> + const struct drm_display_info *info = &connector->display_info; >> + int vfdb_len = cea_db_payload_len(db); >> + struct drm_display_mode *mode; >> + struct cta_vfd vfd; >> + int num_modes = 0; >> + int rate_idx; >> + int vfd_len; >> + int rate; >> + int i; >> + >> + if (!vfdb_len) >> + return 0; >> + >> + vfd_len = (db->data[0] & 0x3); >> + >> + if (!vfd_len) >> + return 0; >> + >> + vfd_len++; >> + vfdb_len--; >> + vfdb_len -= (vfdb_len % vfd_len); >> + >> + for (i = 0; i < vfdb_len; i += vfd_len) { >> + parse_cta_vfd(&vfd, &db->data[i + 1], vfd_len); >> + >> + for (rate_idx = 1; rate_idx < >> + ARRAY_SIZE(video_format_frame_rates); rate_idx++) { >> + rate = video_format_frame_rates[rate_idx]; >> + >> + if (!vfd_has_fr(&vfd, rate) || find_vic(vfd.rid, >> + rate_idx)) >> + continue; >> + >> + mode = drm_ovt_mode(connector->dev, vfd.rid, rate); >> + >> + if (!mode) >> + continue; >> + >> + mode->height_mm = info->height_mm; >> + mode->width_mm = info->width_mm; >> + >> + drm_mode_probed_add(connector, mode); >> + num_modes++; >> + } >> + } >> + >> + return num_modes; >> +} >> + >> /* >> * CTA-861 YCbCr 4:2:0 Capability Map Data Block (CTA Y420CMDB) >> * >> @@ -5318,6 +5781,8 @@ static int add_cea_modes(struct drm_connector *connector, >> /* Add 4:2:0(only) modes present in EDID */ >> modes += do_y420vdb_modes(connector, vdb420, >> cea_db_payload_len(db) - 1); >> + } else if (cea_db_tag(db) == CTA_DB_VIDEO_FORMAT) { >> + modes += add_modes_from_vfdb(connector, db); >> } >> } >> cea_db_iter_end(&iter); >> diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h >> index eaac5e665892..78831207ec65 100644 >> --- a/include/drm/drm_edid.h >> +++ b/include/drm/drm_edid.h >> @@ -450,6 +450,9 @@ struct drm_display_mode * >> drm_display_mode_from_cea_vic(struct drm_device *dev, >> u8 video_code); >> >> +struct drm_display_mode *drm_ovt_mode(struct drm_device *dev, int rid, >> + int vrefresh); >> + >> /* Interface based on struct drm_edid */ >> const struct drm_edid *drm_edid_alloc(const void *edid, size_t size); >> const struct drm_edid *drm_edid_dup(const struct drm_edid *drm_edid); >> -- >> 2.46.1 >> -- Jani Nikula, Intel
