Re: [PATCH v2 13/19] drm/msm/dp: add VSC SDP support for YUV420 over DP

[Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>]

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;
> > >   }
> > >
> > > +static void dp_catalog_panel_send_vsc_sdp(struct dp_catalog 
> > > *dp_catalog, u32 *buffer)
> > > +{
> > > +       struct dp_catalog_private *catalog;
> > > +
> > > +       if (!dp_catalog) {
> > > +               DRM_ERROR("invalid input\n");
> > > +               return;
> > > +       }
> > > +
> > > +       catalog = container_of(dp_catalog, struct dp_catalog_private, 
> > > dp_catalog);
> > > +
> > > +       dp_write_link(catalog, MMSS_DP_GENERIC0_0, buffer[0]);
> > > +       dp_write_link(catalog, MMSS_DP_GENERIC0_1, buffer[1]);
> > > +       dp_write_link(catalog, MMSS_DP_GENERIC0_2, buffer[2]);
> > > +       dp_write_link(catalog, MMSS_DP_GENERIC0_3, buffer[3]);
> > > +       dp_write_link(catalog, MMSS_DP_GENERIC0_4, buffer[4]);
> > > +       dp_write_link(catalog, MMSS_DP_GENERIC0_5, buffer[5]);
> > > +       dp_write_link(catalog, MMSS_DP_GENERIC0_6, buffer[6]);
> > > +       dp_write_link(catalog, MMSS_DP_GENERIC0_7, buffer[7]);
> > > +       dp_write_link(catalog, MMSS_DP_GENERIC0_8, buffer[8]);
> > > +       dp_write_link(catalog, MMSS_DP_GENERIC0_9, buffer[9]);
> > > +}
> > > +
> > > +static void dp_catalog_panel_update_sdp(struct dp_catalog *dp_catalog)
> > > +{
> > > +       struct dp_catalog_private *catalog;
> > > +       u32 hw_revision;
> > > +
> > > +       catalog = container_of(dp_catalog, struct dp_catalog_private, 
> > > dp_catalog);
> > > +
> > > +       hw_revision = dp_catalog_hw_revision(dp_catalog);
> > > +       if (hw_revision < DP_HW_VERSION_1_2 && hw_revision >= 
> > > DP_HW_VERSION_1_0) {
> > > +               dp_write_link(catalog, MMSS_DP_SDP_CFG3, 0x01);
> > > +               dp_write_link(catalog, MMSS_DP_SDP_CFG3, 0x00);
> > > +       }
> > > +}
> > > +
> > > +void dp_catalog_panel_enable_vsc_sdp(struct dp_catalog *dp_catalog, 
> > > u32 *gen_buffer)
> > > +{
> > > +       struct dp_catalog_private *catalog;
> > > +       u32 cfg, cfg2, misc;
> > > +
> > > +       if (!dp_catalog) {
> > > +               DRM_ERROR("invalid input\n");
> > > +               return;
> > > +       }
> > > +
> > > +       catalog = container_of(dp_catalog, struct dp_catalog_private, 
> > > dp_catalog);
> > > +
> > > +       cfg = dp_read_link(catalog, MMSS_DP_SDP_CFG);
> > > +       cfg2 = dp_read_link(catalog, MMSS_DP_SDP_CFG2);
> > > +       misc = dp_read_link(catalog, REG_DP_MISC1_MISC0);
> > > +
> > > +       cfg |= GEN0_SDP_EN;
> > > +       dp_write_link(catalog, MMSS_DP_SDP_CFG, cfg);
> > > +
> > > +       cfg2 |= GENERIC0_SDPSIZE_VALID;
> > > +       dp_write_link(catalog, MMSS_DP_SDP_CFG2, cfg2);
> > > +
> > > +       dp_catalog_panel_send_vsc_sdp(dp_catalog, gen_buffer);
> > > +
> > > +       /* indicates presence of VSC (BIT(6) of MISC1) */
> > > +       misc |= DP_MISC1_VSC_SDP;
> > > +
> > > +       drm_dbg_dp(catalog->drm_dev, "vsc sdp enable=1\n");
> > > +
> > > +       pr_debug("misc settings = 0x%x\n", misc);
> > > +       dp_write_link(catalog, REG_DP_MISC1_MISC0, misc);
> > > +
> > > +       dp_catalog_panel_update_sdp(dp_catalog);
> > > +}
> > > +
> > > +void dp_catalog_panel_disable_vsc_sdp(struct dp_catalog *dp_catalog)
> > > +{
> > > +       struct dp_catalog_private *catalog;
> > > +       u32 cfg, cfg2, misc;
> > > +
> > > +       if (!dp_catalog) {
> > > +               DRM_ERROR("invalid input\n");
> > > +               return;
> > > +       }
> > > +
> > > +       catalog = container_of(dp_catalog, struct dp_catalog_private, 
> > > dp_catalog);
> > > +
> > > +       cfg = dp_read_link(catalog, MMSS_DP_SDP_CFG);
> > > +       cfg2 = dp_read_link(catalog, MMSS_DP_SDP_CFG2);
> > > +       misc = dp_read_link(catalog, REG_DP_MISC1_MISC0);
> > > +
> > > +       cfg &= ~GEN0_SDP_EN;
> > > +       dp_write_link(catalog, MMSS_DP_SDP_CFG, cfg);
> > > +
> > > +       cfg2 &= ~GENERIC0_SDPSIZE_VALID;
> > > +       dp_write_link(catalog, MMSS_DP_SDP_CFG2, cfg2);
> > > +
> > > +       /* switch back to MSA */
> > > +       misc &= ~DP_MISC1_VSC_SDP;
> > > +
> > > +       drm_dbg_dp(catalog->drm_dev, "vsc sdp enable=0\n");
> > > +
> > > +       pr_debug("misc settings = 0x%x\n", misc);
> > > +       dp_write_link(catalog, REG_DP_MISC1_MISC0, misc);
> > > +
> > > +       dp_catalog_panel_update_sdp(dp_catalog);
> > > +}
> > > +
> > >   void dp_catalog_panel_tpg_enable(struct dp_catalog *dp_catalog,
> > >                                  struct drm_display_mode *drm_mode)
> > >   {
> > > diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.h 
> > > b/drivers/gpu/drm/msm/dp/dp_catalog.h
> > > index 6cb5e2a243de2..5b3a7ba40d55f 100644
> > > --- a/drivers/gpu/drm/msm/dp/dp_catalog.h
> > > +++ b/drivers/gpu/drm/msm/dp/dp_catalog.h
> > > @@ -7,6 +7,7 @@
> > >   #define _DP_CATALOG_H_
> > >
> > >   #include <drm/drm_modes.h>
> > > +#include <drm/display/drm_dp_helper.h>
> > >
> > >   #include "dp_parser.h"
> > >   #include "disp/msm_disp_snapshot.h"
> > > @@ -30,6 +31,9 @@
> > >
> > >   #define DP_AUX_CFG_MAX_VALUE_CNT 3
> > >
> > > +#define DP_HW_VERSION_1_0      0x10000000
> > > +#define DP_HW_VERSION_1_2      0x10020000
> > > +
> > >   /* PHY AUX config registers */
> > >   enum dp_phy_aux_config_type {
> > >          PHY_AUX_CFG0,
> > > @@ -124,6 +128,8 @@ u32 dp_catalog_ctrl_read_phy_pattern(struct 
> > > dp_catalog *dp_catalog);
> > >
> > >   /* DP Panel APIs */
> > >   int dp_catalog_panel_timing_cfg(struct dp_catalog *dp_catalog);
> > > +void dp_catalog_panel_enable_vsc_sdp(struct dp_catalog *dp_catalog, 
> > > u32 *gen_buffer);
> > > +void dp_catalog_panel_disable_vsc_sdp(struct dp_catalog *dp_catalog);
> > >   void dp_catalog_dump_regs(struct dp_catalog *dp_catalog);
> > >   void dp_catalog_panel_tpg_enable(struct dp_catalog *dp_catalog,
> > >                                  struct drm_display_mode *drm_mode);
> > > diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c 
> > > b/drivers/gpu/drm/msm/dp/dp_ctrl.c
> > > index 209cf2a35642f..beef86b1aaf81 100644
> > > --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
> > > +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
> > > @@ -1952,6 +1952,8 @@ int dp_ctrl_off_link_stream(struct dp_ctrl 
> > > *dp_ctrl)
> > >          dp_io = &ctrl->parser->io;
> > >          phy = dp_io->phy;
> > >
> > > +       dp_catalog_panel_disable_vsc_sdp(ctrl->catalog);
> > > +
> > >          /* set dongle to D3 (power off) mode */
> > >          dp_link_psm_config(ctrl->link, &ctrl->panel->link_info, true);
> > >
> > > @@ -2026,6 +2028,8 @@ int dp_ctrl_off(struct dp_ctrl *dp_ctrl)
> > >          dp_io = &ctrl->parser->io;
> > >          phy = dp_io->phy;
> > >
> > > +       dp_catalog_panel_disable_vsc_sdp(ctrl->catalog);
> > > +
> > >          dp_catalog_ctrl_mainlink_ctrl(ctrl->catalog, false);
> > >
> > >          dp_catalog_ctrl_reset(ctrl->catalog);
> > > diff --git a/drivers/gpu/drm/msm/dp/dp_panel.c 
> > > b/drivers/gpu/drm/msm/dp/dp_panel.c
> > > index db1942794f1a4..82897edf25e0f 100644
> > > --- a/drivers/gpu/drm/msm/dp/dp_panel.c
> > > +++ b/drivers/gpu/drm/msm/dp/dp_panel.c
> > > @@ -4,6 +4,7 @@
> > >    */
> > >
> > >   #include "dp_panel.h"
> > > +#include "dp_utils.h"
> > >
> > >   #include <drm/drm_connector.h>
> > >   #include <drm/drm_edid.h>
> > > @@ -281,6 +282,60 @@ void dp_panel_tpg_config(struct dp_panel 
> > > *dp_panel, bool enable)
> > >          dp_catalog_panel_tpg_enable(catalog, 
> > > &panel->dp_panel.dp_mode.drm_mode);
> > >   }
> > >
> > > +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.
>
> > > +
> > > +       /* 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. 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.
>
> > > +
> > > +       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.

> 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.
>
> 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.
>
> Thats why I wrote even in V1 that I will certainly do the migration to 
> dp_utils for this one but cannot commit for hdmi.c in this series.
>
> > > +       u8 bpc;
> > > +       int ret = 0;
> > > +
> > > +       if (buff_size < DP_VSC_SDP_BUFFER_SIZE)
> > > +               return -ENOSPC;
> > > +
> > > +       ret = dp_utils_pack_sdp_header(sdp_header, buffer, buff_size);
> > > +       if (ret) {
> > > +               DRM_ERROR("unable to pack sdp header\n");
> > > +               return ret;
> > > +       }
> > > +
> > > +       switch (vsc_sdp_data->bpc) {
> > > +       case 10:
> > > +               bpc = DP_GENERIC0_6_YUV_10_BPC;
> > > +               break;
> > > +       case 8:
> > > +       default:
> > > +               bpc = DP_GENERIC0_6_YUV_8_BPC;
> > > +               break;
> > > +       }
> > > +
> > > +       /* VSC SDP payload as per table 2-117 of DP 1.4 specification */
> > > +       buffer[6] = (vsc_sdp_data->colorimetry & 0xF) |
> > > +              ((vsc_sdp_data->pixelformat & 0xF) << 4) |
> > > +              (bpc << 8) |
> > > +              ((vsc_sdp_data->dynamic_range & 0x1) << 15) |
> > > +              ((vsc_sdp_data->content_type & 0x7) << 16);
> > > +
> > > +       print_hex_dump(KERN_DEBUG, "[drm-dp] VSC: ", 
> > > DUMP_PREFIX_NONE, 16, 4, buffer,
> > > +                      sizeof(buffer), false);
> > > +
> > > +       return ret;
> > > +}
> > > diff --git a/drivers/gpu/drm/msm/dp/dp_utils.h 
> > > b/drivers/gpu/drm/msm/dp/dp_utils.h
> > > index c062e29d07898..7fd775de553c9 100644
> > > --- a/drivers/gpu/drm/msm/dp/dp_utils.h
> > > +++ b/drivers/gpu/drm/msm/dp/dp_utils.h
> > > @@ -18,5 +18,8 @@
> > >   u8 dp_utils_get_g0_value(u8 data);
> > >   u8 dp_utils_get_g1_value(u8 data);
> > >   u8 dp_utils_calculate_parity(u32 data);
> > > +int dp_utils_pack_sdp_header(struct dp_sdp_header *sdp_header, u32 
> > > *buffer, size_t buff_size);
> > > +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);
> > >
> > >   #endif /* _DP_UTILS_H_ */
> > > --
> > > 2.39.2