Hi Ville,
On 04-01-2017 13:22, Ville Syrjälä wrote:
> On Fri, Dec 30, 2016 at 04:53:16PM +0000, Jose Abreu wrote:
>> HDMI 2.0 introduces a new sampling mode called YCbCr 4:2:0.
>> According to the spec the EDID may contain two blocks that
>> signal this sampling mode:
>> - YCbCr 4:2:0 Video Data Block
>> - YCbCr 4:2:0 Video Capability Map Data Block
>>
>> The video data block contains the list of vic's were
>> only YCbCr 4:2:0 sampling mode shall be used while the
>> video capability map data block contains a mask were
>> YCbCr 4:2:0 sampling mode may be used.
>>
>> This RFC patch adds support for parsing these two new blocks
>> and introduces new flags to signal the drivers if the
>> mode is 4:2:0'only or 4:2:0'able.
>>
>> The reason this is still a RFC is because there is no
>> reference in kernel for this new sampling mode (specially in
>> AVI infoframe part), so, I was hoping to hear some feedback
>> first.
>>
>> Tested in a HDMI 2.0 compliance scenario.
>>
>> Signed-off-by: Jose Abreu <joabreu at synopsys.com>
>> Cc: Carlos Palminha <palminha at synopsys.com>
>> Cc: Daniel Vetter <daniel.vetter at intel.com>
>> Cc: Jani Nikula <jani.nikula at linux.intel.com>
>> Cc: Sean Paul <seanpaul at chromium.org>
>> Cc: David Airlie <airlied at linux.ie>
>> Cc: dri-devel at lists.freedesktop.org
>> Cc: linux-kernel at vger.kernel.org
>> ---
>> drivers/gpu/drm/drm_edid.c | 139
>> +++++++++++++++++++++++++++++++++++++++++++-
>> drivers/gpu/drm/drm_modes.c | 10 +++-
>> include/uapi/drm/drm_mode.h | 6 ++
>> 3 files changed, 151 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
>> index 67d6a73..6ce1a38 100644
>> --- a/drivers/gpu/drm/drm_edid.c
>> +++ b/drivers/gpu/drm/drm_edid.c
>> @@ -2549,6 +2549,8 @@ static int drm_cvt_modes(struct drm_connector
>> *connector,
>> #define VENDOR_BLOCK 0x03
>> #define SPEAKER_BLOCK 0x04
>> #define VIDEO_CAPABILITY_BLOCK 0x07
>> +#define VIDEO_DATA_BLOCK_420 0x0E
>> +#define VIDEO_CAP_BLOCK_420 0x0F
>> #define EDID_BASIC_AUDIO (1 << 6)
>> #define EDID_CEA_YCRCB444 (1 << 5)
>> #define EDID_CEA_YCRCB422 (1 << 4)
>> @@ -3050,6 +3052,98 @@ static int add_3d_struct_modes(struct drm_connector
>> *connector, u16 structure,
>> return modes;
>> }
>>
>> +static int add_420_mode(struct drm_connector *connector, u8 vic)
>> +{
>> + struct drm_device *dev = connector->dev;
>> + struct drm_display_mode *newmode;
>> +
>> + if (!drm_valid_cea_vic(vic))
>> + return 0;
>> +
>> + newmode = drm_mode_duplicate(dev, &edid_cea_modes[vic]);
>> + if (!newmode)
>> + return 0;
>> +
>> + newmode->flags |= DRM_MODE_FLAG_420_ONLY;
> Why does userspace need to know this? My thinking has been that the
> driver would do the right thing automagically.
>
> We do probably want some kind of output colorspace property to allow the
> user to select between RGB vs. YCbCr etc. But I think even with that we
> should still allow the driver to automagically select YCbCr 4:2:0 output
> since that's the only way the mode will work.
I agree. When only 4:2:0 is supported there is no need to expose
the flag to userspace. How shall then I signal drivers for this
4:2:0'only sampling mode?
So, for the remaining modes, you propose a new field in the mode
structure called 'colorspace' which contains the list of
supported sampling modes for the given mode? I think it would be
a nice addition. This way if a mode supports only RGB we only
passed RGB flag; if 4:2:0 was also supported we passed the 4:2:0
flag, ... And then user could select. We also have to inform user
which one is being actually used.
Best regards,
Jose Miguel Abreu
>
>> + drm_mode_probed_add(connector, newmode);
>> +
>> + return 1;
>> +}
>> +
>> +static int add_420_vdb_modes(struct drm_connector *connector, const u8
>> *svds,
>> + u8 svds_len)
>> +{
>> + int modes = 0, i;
>> +
>> + for (i = 0; i < svds_len; i++)
>> + modes += add_420_mode(connector, svds[i]);
>> +
>> + return modes;
>> +}
>> +
>> +static int add_420_vcb_modes(struct drm_connector *connector, const u8
>> *svds,
>> + u8 svds_len, const u8 *video_db, u8 video_len)
>> +{
>> + struct drm_display_mode *newmode = NULL;
>> + int modes = 0, i, j;
>> +
>> + for (i = 0; i < svds_len; i++) {
>> + u8 mask = svds[i];
>> + for (j = 0; j < 8; j++) {
>> + if (mask & (1 << j)) {
>> + newmode = drm_display_mode_from_vic_index(
>> + connector, video_db, video_len,
>> + i * 8 + j);
>> + if (newmode) {
>> + newmode->flags |= DRM_MODE_FLAG_420;
>> + drm_mode_probed_add(connector, newmode);
>> + modes++;
>> + }
>> + }
>> + }
>> + }
>> +
>> + return modes;
>> +}
>> +
>> +static int add_420_vcb_modes_all(struct drm_connector *connector,
>> + const u8 *video_db, u8 video_len)
>> +{
>> + struct drm_display_mode *newmode = NULL;
>> + int modes = 0, i;
>> +
>> + for (i = 0; i < video_len; i++) {
>> + newmode = drm_display_mode_from_vic_index(connector, video_db,
>> + video_len, i);
>> + if (newmode) {
>> + newmode->flags |= DRM_MODE_FLAG_420;
>> + drm_mode_probed_add(connector, newmode);
>> + modes++;
>> + }
>> + }
>> +
>> + return modes;
>> +}
>> +
>> +static int do_hdmi_420_modes(struct drm_connector *connector, const u8 *vdb,
>> + u8 vdb_len, const u8 *vcb, u8 vcb_len, const u8 *video_db,
>> + u8 video_len)
>> +{
>> + int modes = 0;
>> +
>> + if (vdb && (vdb_len > 1)) /* Add 4:2:0 modes present in EDID */
>> + modes += add_420_vdb_modes(connector, &vdb[2], vdb_len - 1);
>> +
>> + if (vcb && (vcb_len > 1)) /* Parse bit mask of supported modes */
>> + modes += add_420_vcb_modes(connector, &vcb[2], vcb_len - 1,
>> + video_db, video_len);
>> + else if (vcb) /* All modes support 4:2:0 mode */
>> + modes += add_420_vcb_modes_all(connector, video_db, video_len);
>> +
>> + DRM_DEBUG("added %d 4:2:0 modes\n", modes);
>> + return modes;
>> +}
>> +
>> /*
>> * do_hdmi_vsdb_modes - Parse the HDMI Vendor Specific data block
>> * @connector: connector corresponding to the HDMI sink
>> @@ -3206,6 +3300,12 @@ static int add_3d_struct_modes(struct drm_connector
>> *connector, u16 structure,
>> }
>>
>> static int
>> +cea_db_extended_tag(const u8 *db)
>> +{
>> + return db[1];
>> +}
>> +
>> +static int
>> cea_revision(const u8 *cea)
>> {
>> return cea[1];
>> @@ -3239,6 +3339,28 @@ static bool cea_db_is_hdmi_vsdb(const u8 *db)
>> return hdmi_id == HDMI_IEEE_OUI;
>> }
>>
>> +static bool cea_db_is_hdmi_vdb420(const u8 *db)
>> +{
>> + if (cea_db_tag(db) != VIDEO_CAPABILITY_BLOCK)
>> + return false;
>> +
>> + if (cea_db_extended_tag(db) != VIDEO_DATA_BLOCK_420)
>> + return false;
>> +
>> + return true;
>> +}
>> +
>> +static bool cea_db_is_hdmi_vcb420(const u8 *db)
>> +{
>> + if (cea_db_tag(db) != VIDEO_CAPABILITY_BLOCK)
>> + return false;
>> +
>> + if (cea_db_extended_tag(db) != VIDEO_CAP_BLOCK_420)
>> + return false;
>> +
>> + return true;
>> +}
>> +
>> #define for_each_cea_db(cea, i, start, end) \
>> for ((i) = (start); (i) < (end) && (i) +
>> cea_db_payload_len(&(cea)[(i)]) < (end); (i) +=
>> cea_db_payload_len(&(cea)[(i)]) + 1)
>>
>> @@ -3246,8 +3368,9 @@ static bool cea_db_is_hdmi_vsdb(const u8 *db)
>> add_cea_modes(struct drm_connector *connector, struct edid *edid)
>> {
>> const u8 *cea = drm_find_cea_extension(edid);
>> - const u8 *db, *hdmi = NULL, *video = NULL;
>> - u8 dbl, hdmi_len, video_len = 0;
>> + const u8 *db, *hdmi = NULL, *video = NULL, *vdb420 = NULL,
>> + *vcb420 = NULL;
>> + u8 dbl, hdmi_len, video_len = 0, vdb420_len = 0, vcb420_len = 0;
>> int modes = 0;
>>
>> if (cea && cea_revision(cea) >= 3) {
>> @@ -3269,6 +3392,14 @@ static bool cea_db_is_hdmi_vsdb(const u8 *db)
>> hdmi = db;
>> hdmi_len = dbl;
>> }
>> + else if (cea_db_is_hdmi_vdb420(db)) {
>> + vdb420 = db;
>> + vdb420_len = dbl;
>> + }
>> + else if (cea_db_is_hdmi_vcb420(db)) {
>> + vcb420 = db;
>> + vcb420_len = dbl;
>> + }
>> }
>> }
>>
>> @@ -3280,6 +3411,10 @@ static bool cea_db_is_hdmi_vsdb(const u8 *db)
>> modes += do_hdmi_vsdb_modes(connector, hdmi, hdmi_len, video,
>> video_len);
>>
>> + if (vdb420 || vcb420)
>> + modes += do_hdmi_420_modes(connector, vdb420, vdb420_len,
>> + vcb420, vcb420_len, video, video_len);
>> +
>> return modes;
>> }
>>
>> diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
>> index ac6a352..53c65f6 100644
>> --- a/drivers/gpu/drm/drm_modes.c
>> +++ b/drivers/gpu/drm/drm_modes.c
>> @@ -967,6 +967,10 @@ bool drm_mode_equal_no_clocks(const struct
>> drm_display_mode *mode1, const struct
>> (mode2->flags & DRM_MODE_FLAG_3D_MASK))
>> return false;
>>
>> + if ((mode1->flags & DRM_MODE_FLAG_420_MASK) !=
>> + (mode2->flags & DRM_MODE_FLAG_420_MASK))
>> + return false;
>> +
>> return drm_mode_equal_no_clocks_no_stereo(mode1, mode2);
>> }
>> EXPORT_SYMBOL(drm_mode_equal_no_clocks);
>> @@ -985,6 +989,9 @@ bool drm_mode_equal_no_clocks(const struct
>> drm_display_mode *mode1, const struct
>> bool drm_mode_equal_no_clocks_no_stereo(const struct drm_display_mode
>> *mode1,
>> const struct drm_display_mode *mode2)
>> {
>> + unsigned int flags_mask =
>> + ~(DRM_MODE_FLAG_3D_MASK | DRM_MODE_FLAG_420_MASK);
>> +
>> if (mode1->hdisplay == mode2->hdisplay &&
>> mode1->hsync_start == mode2->hsync_start &&
>> mode1->hsync_end == mode2->hsync_end &&
>> @@ -995,8 +1002,7 @@ bool drm_mode_equal_no_clocks_no_stereo(const struct
>> drm_display_mode *mode1,
>> mode1->vsync_end == mode2->vsync_end &&
>> mode1->vtotal == mode2->vtotal &&
>> mode1->vscan == mode2->vscan &&
>> - (mode1->flags & ~DRM_MODE_FLAG_3D_MASK) ==
>> - (mode2->flags & ~DRM_MODE_FLAG_3D_MASK))
>> + (mode1->flags & flags_mask) == (mode2->flags & flags_mask))
>> return true;
>>
>> return false;
>> diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h
>> index ce7efe2..dc8e285 100644
>> --- a/include/uapi/drm/drm_mode.h
>> +++ b/include/uapi/drm/drm_mode.h
>> @@ -84,6 +84,12 @@
>> #define DRM_MODE_FLAG_3D_L_DEPTH_GFX_GFX_DEPTH (6<<14)
>> #define DRM_MODE_FLAG_3D_TOP_AND_BOTTOM (7<<14)
>> #define DRM_MODE_FLAG_3D_SIDE_BY_SIDE_HALF (8<<14)
>> +/*
>> + * HDMI 2.0
>> + */
>> +#define DRM_MODE_FLAG_420_MASK (0x03<<19)
>> +#define DRM_MODE_FLAG_420 (1<<19)
>> +#define DRM_MODE_FLAG_420_ONLY (1<<20)
>>
>> /* Picture aspect ratio options */
>> #define DRM_MODE_PICTURE_ASPECT_NONE 0
>> --
>> 1.9.1
>>
>>
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>>
