Re: [REPOST PATCH v4 13/13] drm/msm/dsi: Add support for DSC configuration

Marijn Suijten
2022-02-17T09:27:20Z

Vinod,

On 2022-02-10 16:04:23, Vinod Koul wrote:
> When DSC is enabled, we need to configure DSI registers accordingly and
> configure the respective stream compression registers.
>
> Add support to calculate the register setting based on DSC params and
> timing information and configure these registers.
>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Signed-off-by: Vinod Koul <vkoul@kernel.org>

I supplied a rather extensive - yet merely scratching the surface -
review of this patch in:

https://lore.kernel.org/linux-arm-msm/20211211000315.pavmcc7cc73ilb6l@SoMainline.org/

It seems none of those points have been addressed, bar creating a mesa
MR to update dsi.xml with a subpar description of the registers (offsets
only).

For every point that is intentionally ignored, please at least supply a
justification of why you think this is the right thing to do.

Thanks,
- Marijn

> ---
> drivers/gpu/drm/msm/dsi/dsi.xml.h | 10 +++
> drivers/gpu/drm/msm/dsi/dsi_host.c | 109 ++++++++++++++++++++++++++++-
> 2 files changed, 118 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/msm/dsi/dsi.xml.h b/drivers/gpu/drm/msm/dsi/dsi.xml.h
> index 49b551ad1bff..c1c85df58c4b 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi.xml.h
> +++ b/drivers/gpu/drm/msm/dsi/dsi.xml.h
> @@ -706,4 +706,14 @@ static inline uint32_t DSI_VERSION_MAJOR(uint32_t val)
> #define REG_DSI_CPHY_MODE_CTRL 0x000002d4
>
>
> +#define REG_DSI_VIDEO_COMPRESSION_MODE_CTRL 0x0000029c
> +
> +#define REG_DSI_VIDEO_COMPRESSION_MODE_CTRL2 0x000002a0
> +
> +#define REG_DSI_COMMAND_COMPRESSION_MODE_CTRL 0x000002a4
> +
> +#define REG_DSI_COMMAND_COMPRESSION_MODE_CTRL2 0x000002a8
> +
> +#define REG_DSI_COMMAND_COMPRESSION_MODE_CTRL3 0x000002ac
> +
> #endif /* DSI_XML */
> diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
> index 438c80750682..3d8d5a1daaa3 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi_host.c
> +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
> @@ -908,6 +908,20 @@ static void dsi_ctrl_config(struct msm_dsi_host *msm_host, bool enable,
> dsi_write(msm_host, REG_DSI_CPHY_MODE_CTRL, BIT(0));
> }
>
> +static int dsi_dsc_update_pic_dim(struct msm_display_dsc_config *dsc,
> + int pic_width, int pic_height)
> +{
> + if (!dsc || !pic_width || !pic_height) {
> + pr_err("DSI: invalid input: pic_width: %d pic_height: %d\n", pic_width, pic_height);
> + return -EINVAL;
> + }
> +
> + dsc->drm->pic_width = pic_width;
> + dsc->drm->pic_height = pic_height;
> +
> + return 0;
> +}
> +
> static void dsi_timing_setup(struct msm_dsi_host *msm_host, bool is_bonded_dsi)
> {
> struct drm_display_mode *mode = msm_host->mode;
> @@ -940,7 +954,68 @@ static void dsi_timing_setup(struct msm_dsi_host *msm_host, bool is_bonded_dsi)
> hdisplay /= 2;
> }
>
> + if (msm_host->dsc) {
> + struct msm_display_dsc_config *dsc = msm_host->dsc;
> +
> + /* update dsc params with timing params */
> + dsi_dsc_update_pic_dim(dsc, mode->hdisplay, mode->vdisplay);
> + DBG("Mode Width- %d x Height %d\n", dsc->drm->pic_width, dsc->drm->pic_height);
> +
> + /* we do the calculations for dsc parameters here so that
> + * panel can use these parameters
> + */
> + dsi_populate_dsc_params(dsc);
> +
> + /* Divide the display by 3 but keep back/font porch and
> + * pulse width same
> + */
> + h_total -= hdisplay;
> + hdisplay /= 3;
> + h_total += hdisplay;
> + ha_end = ha_start + hdisplay;
> + }
> +
> if (msm_host->mode_flags & MIPI_DSI_MODE_VIDEO) {
> + if (msm_host->dsc) {
> + struct msm_display_dsc_config *dsc = msm_host->dsc;
> + u32 reg, intf_width, slice_per_intf;
> + u32 total_bytes_per_intf;
> +
> + /* first calculate dsc parameters and then program
> + * compress mode registers
> + */
> + intf_width = hdisplay;
> + slice_per_intf = DIV_ROUND_UP(intf_width, dsc->drm->slice_width);
> +
> + dsc->drm->slice_count = 1;
> + dsc->bytes_in_slice = DIV_ROUND_UP(dsc->drm->slice_width * 8, 8);
> + total_bytes_per_intf = dsc->bytes_in_slice * slice_per_intf;
> +
> + dsc->eol_byte_num = total_bytes_per_intf % 3;
> + dsc->pclk_per_line = DIV_ROUND_UP(total_bytes_per_intf, 3);
> + dsc->bytes_per_pkt = dsc->bytes_in_slice * dsc->drm->slice_count;
> + dsc->pkt_per_line = slice_per_intf / dsc->drm->slice_count;
> +
> + reg = dsc->bytes_per_pkt << 16;
> + reg |= (0x0b << 8); /* dtype of compressed image */
> +
> + /* pkt_per_line:
> + * 0 == 1 pkt
> + * 1 == 2 pkt
> + * 2 == 4 pkt
> + * 3 pkt is not supported
> + * above translates to ffs() - 1
> + */
> + reg |= (ffs(dsc->pkt_per_line) - 1) << 6;
> +
> + dsc->eol_byte_num = total_bytes_per_intf % 3;
> + reg |= dsc->eol_byte_num << 4;
> + reg |= 1;
> +
> + dsi_write(msm_host,
> + REG_DSI_VIDEO_COMPRESSION_MODE_CTRL, reg);
> + }
> +
> dsi_write(msm_host, REG_DSI_ACTIVE_H,
> DSI_ACTIVE_H_START(ha_start) |
> DSI_ACTIVE_H_END(ha_end));
> @@ -959,8 +1034,40 @@ static void dsi_timing_setup(struct msm_dsi_host *msm_host, bool is_bonded_dsi)
> DSI_ACTIVE_VSYNC_VPOS_START(vs_start) |
> DSI_ACTIVE_VSYNC_VPOS_END(vs_end));
> } else { /* command mode */
> + if (msm_host->dsc) {
> + struct msm_display_dsc_config *dsc = msm_host->dsc;
> + u32 reg, reg_ctrl, reg_ctrl2;
> + u32 slice_per_intf, bytes_in_slice, total_bytes_per_intf;
> +
> + reg_ctrl = dsi_read(msm_host, REG_DSI_COMMAND_COMPRESSION_MODE_CTRL);
> + reg_ctrl2 = dsi_read(msm_host, REG_DSI_COMMAND_COMPRESSION_MODE_CTRL2);
> +
> + slice_per_intf = DIV_ROUND_UP(hdisplay, dsc->drm->slice_width);
> + bytes_in_slice = DIV_ROUND_UP(dsc->drm->slice_width *
> + dsc->drm->bits_per_pixel, 8);
> + dsc->drm->slice_chunk_size = bytes_in_slice;
> + total_bytes_per_intf = dsc->bytes_in_slice * slice_per_intf;
> + dsc->pkt_per_line = slice_per_intf / dsc->drm->slice_count;
> +
> + reg = 0x39 << 8;
> + reg |= ffs(dsc->pkt_per_line) << 6;
> +
> + dsc->eol_byte_num = total_bytes_per_intf % 3;
> + reg |= dsc->eol_byte_num << 4;
> + reg |= 1;
> +
> + reg_ctrl |= reg;
> + reg_ctrl2 |= bytes_in_slice;
> +
> + dsi_write(msm_host, REG_DSI_COMMAND_COMPRESSION_MODE_CTRL, reg);
> + dsi_write(msm_host, REG_DSI_COMMAND_COMPRESSION_MODE_CTRL2, reg_ctrl2);
> + }
> +
> /* image data and 1 byte write_memory_start cmd */
> - wc = hdisplay * dsi_get_bpp(msm_host->format) / 8 + 1;
> + if (!msm_host->dsc)
> + wc = hdisplay * dsi_get_bpp(msm_host->format) / 8 + 1;
> + else
> + wc = mode->hdisplay / 2 + 1;
>
> dsi_write(msm_host, REG_DSI_CMD_MDP_STREAM0_CTRL,
> DSI_CMD_MDP_STREAM0_CTRL_WORD_COUNT(wc) |
> --
> 2.31.1
>