On Tue, 30 Jul 2024, Hamza Mahfooz <hamza.mahf...@amd.com> 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.
Is VFDB new to CTA-861-I? AFAICT the H version doesn't have it. Is there any particular reason for the two step approach here? I mean first allocating and storing the modes in drm_parse_cea_ext() and then adding them in _drm_edid_connector_add_modes()? I think you could just as well do everything in the latter, without the complications of allocation. See e.g. add_cea_modes() which also iterates the CTA data blocks. I think this would simplify everything considerably. Please find some additional comments inline. I'll do more when I've got hold of CTA-861-I. BR, Jani. > > Link: https://gitlab.freedesktop.org/drm/amd/-/issues/1442 > Suggested-by: Karol Herbst <kher...@redhat.com> > Signed-off-by: Hamza Mahfooz <hamza.mahf...@amd.com> > --- > drivers/gpu/drm/drm_edid.c | 426 ++++++++++++++++++++++++++++++++++++ > include/drm/drm_connector.h | 12 + > 2 files changed, 438 insertions(+) > > diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c > index f68a41eeb1fa..112a0070c4d5 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 +742,93 @@ 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[] = { > + /* RID 0-9 */ > + { 0, 0, 0, 0 }, > + { 1280, 720, 16, 9 }, > + { 1280, 720, 64, 27 }, > + { 1680, 720, 64, 27 }, > + { 1920, 1080, 16, 9 }, > + { 1920, 1080, 64, 27 }, > + { 2560, 1080, 64, 27 }, > + { 3840, 1080, 32, 9 }, > + { 2560, 1440, 16, 9 }, > + { 3440, 1440, 64, 27 }, > + /* RID 10-19 */ > + { 5120, 1440, 32, 9 }, > + { 3840, 2160, 16, 9 }, > + { 3840, 2160, 64, 27 }, > + { 5120, 2160, 64, 27 }, > + { 7680, 2160, 32, 9 }, > + { 5120, 2880, 16, 9 }, > + { 5120, 2880, 64, 27 }, > + { 6880, 2880, 64, 27 }, > + { 10240, 2880, 32, 9 }, > + { 7680, 4320, 16, 9 }, > + /* RID 20-28 */ > + { 7680, 4320, 64, 27 }, > + { 10240, 4320, 64, 27 }, > + { 15360, 4320, 32, 9 }, > + { 11520, 6480, 16, 9 }, > + { 11520, 6480, 64, 27 }, > + { 15360, 6480, 64, 27 }, > + { 15360, 8640, 16, 9 }, > + { 15360, 8640, 64, 27 }, > + { 20480, 8640, 64, 27 }, > +}; > + > +/* CTA-861-I Table 12 - AVI InfoFrame Video Format Frame Rate */ > +static const u16 cta_vf_fr[] = { > + /* 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] = { > + /* RID 0-9 */ > + {}, > + { 60, 61, 62, 108, 19, 4, 41, 47 }, > + { 65, 66, 67, 109, 68, 69, 70, 71 }, > + { 79, 80, 81, 110, 82, 83, 84, 85 }, > + { 32, 33, 34, 111, 31, 16, 64, 63 }, > + { 72, 73, 74, 112, 75, 76, 77, 78 }, > + { 86, 87, 88, 113, 89, 90, 91, 92 }, > + {}, > + {}, > + {}, > + /* RID 10-19 */ > + {}, > + { 93, 94, 95, 114, 96, 97, 117, 118 }, > + { 103, 104, 105, 116, 106, 107, 119, 120 }, > + { 121, 122, 123, 124, 125, 126, 127, 193 }, > + {}, > + {}, > + {}, > + {}, > + {}, > + { 194, 195, 196, 197, 198, 199, 200, 201 }, > + /* RID 20-28 */ > + { 202, 203, 204, 205, 206, 207, 208, 209 }, > + { 210, 211, 212, 213, 214, 215, 216, 217 }, > + {}, > + {}, > + {}, > + {}, > + {}, > + {}, > + {}, > +}; > + > /* > * From CEA/CTA-861 spec. > * > @@ -4140,6 +4228,7 @@ 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 */ > @@ -4981,6 +5070,16 @@ 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; > @@ -6018,6 +6117,307 @@ static void parse_cta_vdb(struct drm_connector > *connector, const struct cea_db * > } > } > > +/* CTA-861 Video Format Descriptor (CTA VFD) */ > +static void parse_cta_vfd(const u8 *data, int vfd_len, struct cta_vfd *vfd) It's customary for the destination parameter to be first. > +{ > + vfd->rid = data[0] & 0x3f; > + vfd->bfr50 = data[0] >> 7; Looks like data[0] & 0x80. But then I don't have the spec yet. > + vfd->fr24 = !!(data[0] & 0x40); > + vfd->bfr60 = vfd_len > 1 ? (data[1] >> 7) : 0x1; Ditto. Why shift if you're only interested in the highest bit? > + vfd->fr144 = vfd_len > 1 ? !!(data[1] & 0x40) : 0x0; > + vfd->fr_fact = vfd_len > 1 ? (data[1] & 0x3f) : 0x3; > + vfd->fr48 = vfd_len > 2 ? !!(data[2] & 0x1) : 0x0; All the !!'s are unnecessary for bool assignment. > +} > + > +static bool vfd_has_fr(const struct cta_vfd *vfd, int rate_idx) > +{ > + static const u8 factors[6] = { Unnecessary explicit arrays size. > + 1, 2, 4, 8, 12, 16 > + }; > + u16 rate = cta_vf_fr[rate_idx]; > + u16 factor = 0; > + unsigned 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 > + > +/* OVT Algorthim as specified in CTA-861-I */ > +static struct drm_display_mode *calculate_ovt_mode(const struct cta_rid *rid, > + u16 vrate, > + struct drm_device *dev) Please pass around struct drm_connector if you have it, and as the context parameter it should be first. > +{ > + u32 max_audio_packets_per_line; > + struct drm_display_mode *mode; > + u32 htotal_granularity_chunk; > + u32 resolution_granularity; > + u32 vtotal_granularity = 1; > + u64 min_pixel_clock_rate; > + u32 htotal_granularity; > + u32 max_vrate = vrate; > + u64 pixel_clock_rate; > + u64 max_active_time; > + u64 min_resolution; > + u32 vsync_position; > + u32 min_line_time; > + u32 min_line_rate; > + u32 min_hblank; > + u32 min_htotal; > + u32 min_vblank; > + u32 min_vtotal; > + u32 htotal; > + u32 vtotal; > + u32 h; > + u64 r; > + u32 v; There's something wrong with *any* function that has this many local variables. > + > + /* step 1 */ > + switch (vrate) { > + 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; > + } > + > + /* step 2 */ > + max_active_time = ((u64)1000000000000 / (u64)max_vrate) - > + (u64)OVT_MIN_VBLANK_DURATION; > + > + min_line_time = max_active_time / (u64)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); > + > + /* 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(DIV_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); > + > + resolution_granularity = OVT_PIXEL_CLOCK_GRANULARITY / > + gcd(OVT_PIXEL_CLOCK_GRANULARITY, max_vrate); > + > + for (;;) { > + /* step 5 */ > + min_resolution = 0; > + v = min_vtotal; > + > + for (;;) { Not a fan of loops without clear loop conditions, let alone two of them nested! It's really hard to figure out this is guaranteed to stop. > + h = min_htotal; > + r = (u64)h * (u64)v; > + > + if (min_resolution && r > min_resolution) > + break; > + > + while (r % resolution_granularity || > + max_vrate * r / (h & ~(h - 1)) > > + OVT_MAX_CHUNK_RATE) { > + h += htotal_granularity; > + r = (u64)h * (u64)v; > + } > + > + if (!min_resolution || r < min_resolution) { > + htotal = h; > + vtotal = v; > + min_resolution = r; > + } > + > + v += vtotal_granularity; > + } > + > + pixel_clock_rate = max_vrate * min_resolution; > + > + /* step 6 */ > + min_htotal = rid->hactive + max(OVT_MIN_HBLANK_420, > + OVT_PIXEL_FACTOR_420 * > + min_hblank); > + if (pixel_clock_rate >= OVT_MIN_CLOCK_RATE_420 && > + htotal < min_htotal) > + continue; > + > + break; > + } > + > + /* step 7 */ > + vtotal = vtotal * max_vrate / vrate; > + > + /* step 8 */ > + vsync_position = max(OVT_MIN_VSYNC_LE_LINES, > + DIV64_U64_ROUND_UP((u64)OVT_MIN_VSYNC_LE_LINES * > + (u64)pixel_clock_rate, > + (u64)htotal * (u64)1000000)); > + > + mode = drm_mode_create(dev); > + > + if (!mode) > + return NULL; > + > + mode->clock = 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; > +} > + > +/* CTA-861 Video Format Data Block (CTA VFDB) */ > +static void parse_cta_vfdb(struct drm_connector *connector, > + const struct cea_db *db) > +{ > + struct drm_display_info *info = &connector->display_info; > + int vfdb_len = cea_db_payload_len(db); > + int vfd_len = (db->data[0] & 0x3) + 1; What if payload len is 0? > + struct drm_display_mode **modes; > + struct drm_display_mode *mode; > + struct cta_vfd vfd; > + int mode_index = 0; > + int i; > + int j; > + > + if (!(vfdb_len - 1) || (vfdb_len - 1) % vfd_len) > + return; Better to check for vfd_len < some minimum. I'd usually not require the modulo is zero, just take as many whole vfd's as there are, and ignore the rest. > + > + modes = krealloc_array(info->ovt_modes, ((vfdb_len - 1) / vfd_len) * > + (ARRAY_SIZE(cta_vf_fr) - 1), > + sizeof(*info->ovt_modes), GFP_KERNEL); > + I really hope we can get rid of this. > + if (!modes) > + return; > + > + for (i = 1; i < vfdb_len; i += vfd_len) { > + parse_cta_vfd(&db->data[i], vfd_len, &vfd); > + > + if (!vfd.rid || vfd.rid >= ARRAY_SIZE(rids)) > + continue; > + > + for (j = 1; j < ARRAY_SIZE(cta_vf_fr); j++) { > + if (!vfd_has_fr(&vfd, j) || > + (cta_vf_fr[j] < 144 && rid_to_vic[vfd.rid][j - 1])) > + continue; > + > + mode = calculate_ovt_mode(&rids[vfd.rid], cta_vf_fr[j], > + connector->dev); > + > + if (!mode) > + continue; > + > + mode->height_mm = info->height_mm; > + mode->width_mm = info->width_mm; > + > + info->ovt_modes[mode_index++] = mode; > + } > + } > + > + info->num_ovt_modes = mode_index; > +} > + > /* > * Update y420_cmdb_modes based on previously parsed CTA VDB and Y420CMDB. > * > @@ -6439,6 +6839,8 @@ static void drm_parse_cea_ext(struct drm_connector > *connector, > parse_cta_vdb(connector, db); > else if (cea_db_tag(db) == CTA_DB_AUDIO) > info->has_audio = true; > + else if (cea_db_tag(db) == CTA_DB_VIDEO_FORMAT) > + parse_cta_vfdb(connector, db); > } > cea_db_iter_end(&iter); > > @@ -6585,6 +6987,7 @@ static void drm_update_mso(struct drm_connector > *connector, > static void drm_reset_display_info(struct drm_connector *connector) > { > struct drm_display_info *info = &connector->display_info; > + int i; > > info->width_mm = 0; > info->height_mm = 0; > @@ -6611,6 +7014,13 @@ static void drm_reset_display_info(struct > drm_connector *connector) > info->mso_pixel_overlap = 0; > info->max_dsc_bpp = 0; > > + for (i = 0; i < info->num_ovt_modes; i++) > + drm_mode_destroy(connector->dev, info->ovt_modes[i]); > + > + kfree(info->ovt_modes); > + info->ovt_modes = NULL; > + info->num_ovt_modes = 0; > + I really hope we can get rid of this. > kfree(info->vics); > info->vics = NULL; > info->vics_len = 0; > @@ -6849,6 +7259,21 @@ static int add_displayid_detailed_modes(struct > drm_connector *connector, > return num_modes; > } > > +static int add_ovt_modes(struct drm_connector *connector) > +{ > + struct drm_display_info *info = &connector->display_info; > + int i; > + > + for (i = 0; i < info->num_ovt_modes; i++) { > + drm_mode_probed_add(connector, info->ovt_modes[i]); > + info->ovt_modes[i] = NULL; > + } > + > + info->num_ovt_modes = 0; > + > + return i; > +} > + > static int _drm_edid_connector_add_modes(struct drm_connector *connector, > const struct drm_edid *drm_edid) > { > @@ -6872,6 +7297,7 @@ static int _drm_edid_connector_add_modes(struct > drm_connector *connector, > * > * XXX order for additional mode types in extension blocks? > */ > + num_modes += add_ovt_modes(connector); Why first? > num_modes += add_detailed_modes(connector, drm_edid); > num_modes += add_cvt_modes(connector, drm_edid); > num_modes += add_standard_modes(connector, drm_edid); > diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h > index 5ad735253413..35b5eb344ea8 100644 > --- a/include/drm/drm_connector.h > +++ b/include/drm/drm_connector.h > @@ -829,6 +829,18 @@ struct drm_display_info { > */ > u32 max_dsc_bpp; > > + /** > + * @ovt_modes: Array of @num_ovt_modes OVT modes. Internal to EDID > + * parsing. > + */ > + struct drm_display_mode **ovt_modes; > + > + /** > + * @num_ovt_modes: Number of elements in @ovt_modes. Internal to EDID > + * parsing. > + */ > + int num_ovt_modes; > + I really hope we can get rid of this. > /** > * @vics: Array of vics_len VICs. Internal to EDID parsing. > */ -- Jani Nikula, Intel
