On Sun, 11 Feb 2024 at 06:06, Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx> wrote:
>
>
>
> On 2/10/2024 1:46 PM, Dmitry Baryshkov wrote:
> > On Sat, 10 Feb 2024 at 20:50, Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx> wrote:
> >>
> >>
> >>
> >> On 2/10/2024 10:14 AM, Abhinav Kumar wrote:
> >>>
> >>>
> >>> On 2/10/2024 2:09 AM, Dmitry Baryshkov wrote:
> >>>> On Sat, 10 Feb 2024 at 03:52, Paloma Arellano
> >>>> <quic_parellan@xxxxxxxxxxx> wrote:
> >>>>>
> >>>>> Add support to pack and send the VSC SDP packet for DP. This therefore
> >>>>> allows the transmision of format information to the sinks which is
> >>>>> needed for YUV420 support over DP.
> >>>>>
> >>>>> Changes in v2:
> >>>>> - Rename GENERIC0_SDPSIZE macro to GENERIC0_SDPSIZE_VALID
> >>>>> - Remove dp_sdp from the dp_catalog struct since this data is
> >>>>> being allocated at the point used
> >>>>> - Create a new function in dp_utils to pack the VSC SDP data
> >>>>> into a buffer
> >>>>> - Create a new function that packs the SDP header bytes into a
> >>>>> buffer. This function is made generic so that it can be
> >>>>> utilized by dp_audio
> >>>>> header bytes into a buffer
> >>>>> - Create a new function in dp_utils that takes the packed
> >>>>> buffer
> >>>>> and writes to the DP_GENERIC0_* registers
> >>>>> - Split the dp_catalog_panel_config_vsc_sdp() function into two
> >>>>> to disable/enable sending VSC SDP packets
> >>>>> - Check the DP HW version using the original useage of
> >>>>> dp_catalog_hw_revision() and correct the version checking
> >>>>> logic
> >>>>> - Rename dp_panel_setup_vsc_sdp() to
> >>>>> dp_panel_setup_vsc_sdp_yuv_420() to explicitly state that
> >>>>> currently VSC SDP is only being set up to support YUV420
> >>>>> modes
> >>>>>
> >>>>> Signed-off-by: Paloma Arellano <quic_parellan@xxxxxxxxxxx>
> >>>>> ---
> >>>>> drivers/gpu/drm/msm/dp/dp_catalog.c | 105 ++++++++++++++++++++++++++++
> >>>>> drivers/gpu/drm/msm/dp/dp_catalog.h | 6 ++
> >>>>> drivers/gpu/drm/msm/dp/dp_ctrl.c | 4 ++
> >>>>> drivers/gpu/drm/msm/dp/dp_panel.c | 59 ++++++++++++++++
> >>>>> drivers/gpu/drm/msm/dp/dp_reg.h | 3 +
> >>>>> drivers/gpu/drm/msm/dp/dp_utils.c | 80 +++++++++++++++++++++
> >>>>> drivers/gpu/drm/msm/dp/dp_utils.h | 3 +
> >>>>> 7 files changed, 260 insertions(+)
> >>>>>
> >>>>> diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.c
> >>>>> b/drivers/gpu/drm/msm/dp/dp_catalog.c
> >>>>> index 5d84c089e520a..0f28a4897b7b7 100644
> >>>>> --- a/drivers/gpu/drm/msm/dp/dp_catalog.c
> >>>>> +++ b/drivers/gpu/drm/msm/dp/dp_catalog.c
> >>>>> @@ -901,6 +901,111 @@ int dp_catalog_panel_timing_cfg(struct
> >>>>> dp_catalog *dp_catalog)
> >>>>> return 0;
> >>>>> }
> >>>>>
>
> <Snip>
>
> >>>>> +static int dp_panel_setup_vsc_sdp_yuv_420(struct dp_panel *dp_panel)
> >>>>> +{
> >>>>> + struct dp_catalog *catalog;
> >>>>> + struct dp_panel_private *panel;
> >>>>> + struct dp_display_mode *dp_mode;
> >>>>> + struct dp_sdp_header sdp_header;
> >>>>> + struct drm_dp_vsc_sdp vsc_sdp_data;
> >>>>> + size_t buff_size;
> >>>>> + u32 gen_buffer[10];
> >>>>> + int rc = 0;
> >>>>> +
> >>>>> + if (!dp_panel) {
> >>>>> + DRM_ERROR("invalid input\n");
> >>>>> + rc = -EINVAL;
> >>>>> + return rc;
> >>>>> + }
> >>>>> +
> >>>>> + panel = container_of(dp_panel, struct dp_panel_private,
> >>>>> dp_panel);
> >>>>> + catalog = panel->catalog;
> >>>>> + dp_mode = &dp_panel->dp_mode;
> >>>>> + buff_size = sizeof(gen_buffer);
> >>>>> +
> >>>>> + memset(&sdp_header, 0, sizeof(sdp_header));
> >>>>> + memset(&vsc_sdp_data, 0, sizeof(vsc_sdp_data));
> >>>>> +
> >>>>> + /* VSC SDP header as per table 2-118 of DP 1.4 specification */
> >>>>> + sdp_header.HB0 = 0x00;
> >>>>> + sdp_header.HB1 = 0x07;
> >>>>> + sdp_header.HB2 = 0x05;
> >>>>> + sdp_header.HB3 = 0x13;
> >>>>
> >>>> This should go to the packing function.
> >>>>
> >>>
> >>> We can .... but ....
> >>>
> >>> the header bytes can change based on the format. These values are
> >>> specific to YUV420. Thats why this part was kept outside of the generic
> >>> vsc sdp packing. Today we support only YUV420 VSC SDP so we can move it
> >>> but this was the reason.
> >
> > These values can be set from the sdp_type, revision and length fields
> > of struct drm_dp_vsc_sdp.
> > The function intel_dp_vsc_sdp_pack() is pretty much close to what I had in mind.
> >
> >>>
> >>>>> +
> >>>>> + /* VSC SDP Payload for DB16 */
> >>>>
> >>>> Comments are useless more or less. The code fills generic information
> >>>> structure which might or might not be packed to the data buffer.
> >>>>
> >>>>> + vsc_sdp_data.pixelformat = DP_PIXELFORMAT_YUV420;
> >>>>> + vsc_sdp_data.colorimetry = DP_COLORIMETRY_DEFAULT;
> >>>>> +
> >>>>> + /* VSC SDP Payload for DB17 */
> >>>>> + vsc_sdp_data.dynamic_range = DP_DYNAMIC_RANGE_CTA;
> >>>>> +
> >>>>> + /* VSC SDP Payload for DB18 */
> >>>>> + vsc_sdp_data.content_type = DP_CONTENT_TYPE_GRAPHICS;
> >>>>> +
> >>>>> + vsc_sdp_data.bpc = dp_mode->bpp / 3;
> >>>>
> >>>> Consider extracting intel_dp_compute_vsc_colorimetry() and using it.
> >>>>
> >>>
> >>> intel_dp_compute_vsc_colorimetry() uses colorspace property to pick
> >>> YUV420, we do not.
> >
> > Intel function also uses output_format, but it's true, it is full of
> > Intel specifics.
> >
> >>> Right now, its a pure driver decision to use YUV420
> >>> when the mode is supported only in that format.
> >>>
> >>> Also, many params are to be used within this function cached inside
> >>> intel_crtc_state . We will first need to make that API more generic to
> >>> be re-usable by others.
> >>>
> >>> I think overall, if we want to have a generic packing across vendors, it
> >>> needs more work. I think one of us can take that up as a separate effort.
> >
> > Ack, I agree here. I did only a quick glance over
> > intel_dp_compute_vsc_colorimetry function() beforehand.
> >
> >>>
> >>>>> +
> >>>>> + rc = dp_utils_pack_vsc_sdp(&vsc_sdp_data, &sdp_header,
> >>>>> gen_buffer, buff_size);
> >>>>> + if (rc) {
> >>>>> + DRM_ERROR("unable to pack vsc sdp\n");
> >>>>> + return rc;
> >>>>> + }
> >>>>> +
> >>>>> + dp_catalog_panel_enable_vsc_sdp(catalog, gen_buffer);
> >>>>> +
> >>>>> + return rc;
> >>>>> +}
> >>>>> +
> >>>>> void dp_panel_dump_regs(struct dp_panel *dp_panel)
> >>>>> {
> >>>>> struct dp_catalog *catalog;
> >>>>> @@ -344,6 +399,10 @@ int dp_panel_timing_cfg(struct dp_panel *dp_panel)
> >>>>> catalog->dp_active = data;
> >>>>>
> >>>>> dp_catalog_panel_timing_cfg(catalog);
> >>>>> +
> >>>>> + if (dp_panel->dp_mode.out_fmt_is_yuv_420)
> >>>>> + dp_panel_setup_vsc_sdp_yuv_420(dp_panel);
> >>>>> +
> >>>>> panel->panel_on = true;
> >>>>>
> >>>>> return 0;
> >>>>> diff --git a/drivers/gpu/drm/msm/dp/dp_reg.h
> >>>>> b/drivers/gpu/drm/msm/dp/dp_reg.h
> >>>>> index ea85a691e72b5..2983756c125cd 100644
> >>>>> --- a/drivers/gpu/drm/msm/dp/dp_reg.h
> >>>>> +++ b/drivers/gpu/drm/msm/dp/dp_reg.h
> >>>>> @@ -142,6 +142,7 @@
> >>>>> #define DP_MISC0_SYNCHRONOUS_CLK (0x00000001)
> >>>>> #define DP_MISC0_COLORIMETRY_CFG_SHIFT (0x00000001)
> >>>>> #define DP_MISC0_TEST_BITS_DEPTH_SHIFT (0x00000005)
> >>>>> +#define DP_MISC1_VSC_SDP (0x00004000)
> >>>>>
> >>>>> #define REG_DP_VALID_BOUNDARY (0x00000030)
> >>>>> #define REG_DP_VALID_BOUNDARY_2 (0x00000034)
> >>>>> @@ -201,9 +202,11 @@
> >>>>> #define MMSS_DP_AUDIO_CTRL_RESET (0x00000214)
> >>>>>
> >>>>> #define MMSS_DP_SDP_CFG (0x00000228)
> >>>>> +#define GEN0_SDP_EN (0x00020000)
> >>>>> #define MMSS_DP_SDP_CFG2 (0x0000022C)
> >>>>> #define MMSS_DP_AUDIO_TIMESTAMP_0 (0x00000230)
> >>>>> #define MMSS_DP_AUDIO_TIMESTAMP_1 (0x00000234)
> >>>>> +#define GENERIC0_SDPSIZE_VALID (0x00010000)
> >>>>>
> >>>>> #define MMSS_DP_AUDIO_STREAM_0 (0x00000240)
> >>>>> #define MMSS_DP_AUDIO_STREAM_1 (0x00000244)
> >>>>> diff --git a/drivers/gpu/drm/msm/dp/dp_utils.c
> >>>>> b/drivers/gpu/drm/msm/dp/dp_utils.c
> >>>>> index 176d839906cec..05e0133eb50f3 100644
> >>>>> --- a/drivers/gpu/drm/msm/dp/dp_utils.c
> >>>>> +++ b/drivers/gpu/drm/msm/dp/dp_utils.c
> >>>>> @@ -4,6 +4,16 @@
> >>>>> */
> >>>>>
> >>>>> #include <linux/types.h>
> >>>>> +#include <drm/display/drm_dp_helper.h>
> >>>>> +#include <drm/drm_print.h>
> >>>>> +
> >>>>> +#include "dp_utils.h"
> >>>>> +
> >>>>> +#define DP_GENERIC0_6_YUV_8_BPC BIT(0)
> >>>>> +#define DP_GENERIC0_6_YUV_10_BPC BIT(1)
> >>>>> +
> >>>>> +#define DP_SDP_HEADER_SIZE 8
> >>>>> +#define DP_VSC_SDP_BUFFER_SIZE 40
> >>>>>
> >>>>> u8 dp_utils_get_g0_value(u8 data)
> >>>>> {
> >>>>> @@ -69,3 +79,73 @@ u8 dp_utils_calculate_parity(u32 data)
> >>>>>
> >>>>> return parity_byte;
> >>>>> }
> >>>>> +
> >>>>> +int dp_utils_pack_sdp_header(struct dp_sdp_header *sdp_header, u32
> >>>>> *buffer, size_t buff_size)
> >>>>> +{
> >>>>> + u32 header, parity;
> >>>>> +
> >>>>> + if (buff_size < DP_SDP_HEADER_SIZE)
> >>>>> + return -ENOSPC;
> >>>>> +
> >>>>> + memset(buffer, 0, sizeof(buffer));
> >>>>> +
> >>>>> + /* HEADER BYTE 0 */
> >>>>> + header = sdp_header->HB0;
> >>>>> + parity = dp_utils_calculate_parity(header);
> >>>>> + buffer[0] = ((header << HEADER_BYTE_0_BIT) | (parity <<
> >>>>> PARITY_BYTE_0_BIT));
> >>>>> +
> >>>>> + /* HEADER BYTE 1 */
> >>>>> + header = sdp_header->HB1;
> >>>>> + parity = dp_utils_calculate_parity(header);
> >>>>> + buffer[0] |= ((header << HEADER_BYTE_1_BIT) | (parity <<
> >>>>> PARITY_BYTE_1_BIT));
> >>>>> +
> >>>>> + /* HEADER BYTE 2 */
> >>>>> + header = sdp_header->HB2;
> >>>>> + parity = dp_utils_calculate_parity(header);
> >>>>> + buffer[1] = ((header << HEADER_BYTE_2_BIT) | (parity <<
> >>>>> PARITY_BYTE_2_BIT));
> >>>>> +
> >>>>> + /* HEADER BYTE 3 */
> >>>>> + header = sdp_header->HB3;
> >>>>> + parity = dp_utils_calculate_parity(header);
> >>>>> + buffer[1] |= ((header << HEADER_BYTE_3_BIT) | (parity <<
> >>>>> PARITY_BYTE_3_BIT));
> >>>>> +
> >>>>> + return 0;
> >>>>> +}
> >>>>> +
> >>>>> +int dp_utils_pack_vsc_sdp(struct drm_dp_vsc_sdp *vsc_sdp_data,
> >>>>> struct dp_sdp_header *sdp_header,
> >>>>> + u32 *buffer, size_t buff_size)
> >>>>> +{
> >>>>
> >>>> No. This function should pack data into struct dp_sdp and it should go
> >>>> to drivers/video/hdmi.c
> >>>>
> >>>
> >>> What is the difference between struct drm_dp_vsc_sdp and struct dp_sdp?
> >>>
> >>
> >> I think you were referring to the fact that instead of a custom buffer,
> >> we should use struct dp_sdp to pack elements from struct drm_dp_vsc_sdp.
> >>
> >> If yes, I agree with this part.
> >
> > Yes.
> >
> >>
> >>> It seems like struct drm_dp_vsc_sdp is more appropriate for this.
> >>>
> >>> Regarding hdmi.c, I think the packing needs to be more generic to move
> >>> it there.
> >>>
> >>> I am not seeing parity bytes packing with other vendors. So there will
> >>> have to be some packing there and then some packing here.
> >
> > Yes. Writing the HB + PB seems specific to Qualcomm hardware. At least
> > Intel and AMD seem to write header bytes without parity.
> >
> >>> Also, like you already noticed, to make the VSC SDP packing more generic
> >>> to move to hdmi.c, it needs more work to make it more usable like
> >>> supporting all pixel formats and all colorimetry values.
> >>>
> >>> We do not have that much utility yet for that.
> >
> > I think you are mixing the filling of drm_dp_vsc_sdp and packing of
> > that struct. I suppose intel_dp_vsc_sdp_pack() can be extracted more
> > or less as is.
> > Once somebody needs to support 3D (AMD does), they can extend the function.
> >
>
> Yes once I corrected my understanding of using the function to just pack
> struct dp_sdp instead of the buffer, I understood the intention.
>
> We can try it. I have written up a RFC to move the
> intel_dp_vsc_sdp_pack() to drm_dp_helper as that seems more appropriate
> now for it and not hdmi.c as we already have some vsc sdp utils in
> drm_dp_helper.
Yes, we have. However all structure manipulation functions, even for
DP, are usually a part of the hdmi.c. If I understand correctly, we
can still touch this file from drm-misc (or from other drm trees).
> But before I post, we will do some cleanup and see if things look
> reasonable in this patch too because we will still need to write a
> common utility to pack the parity bytes for the sdp header which we need
> to utilize for audio and vsc sdp in our DP case.
>
> I am thinking of a
>
> struct msm_dp_sdp_pb {
> u8 PB0;
> u8 PB1;
> u8 PB2;
> u8 PB3;
> } __packed;
>
> struct msm_dp_sdp_with_parity {
> struct dp_sdp vsc_sdp;
> struct msm_dp_sdp_pb pb;
> };
>
> intel_dp_vsc_sdp_pack() will pack the struct dp_sdp but we will have to
> do some additional parity byte packing after that. That part will remain
> common for audio and vsc for msm.
I think you can do it in a much easier way:
struct dp_sdp sdp
u32 header[2];
hdmi_dp_vsc_sdp_pack(vsc_sdp, &sdp);
msm_dp_pack_header(&sdp, header);
dp_write_register(catalog, MMSS_DP_FOO_HEADER0, header[0]);
dp_write_register(catalog, MMSS_DP_FOO_HEADER1, header[1]);
// write sdp.db
--
With best wishes
Dmitry
