Re: [PATCH v6 14/14] drm/msm/dsi: Add support for DSC configuration

[Vinod Koul <vkoul@kernel.org>]

On 06-04-22, 02:42, Dmitry Baryshkov wrote:
> On 04/04/2022 19:34, 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>
> > ---
> >   drivers/gpu/drm/msm/dsi/dsi_host.c | 98 +++++++++++++++++++++++++++++-
> >   1 file changed, 97 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
> > index eb0be34add45..f3ed6c40b9e1 100644
> > --- a/drivers/gpu/drm/msm/dsi/dsi_host.c
> > +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
> > @@ -912,6 +912,65 @@ 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 void dsi_update_dsc_timing(struct msm_dsi_host *msm_host, bool is_cmd_mode, u32 hdisplay)
> > +{
> > +	struct msm_display_dsc_config *dsc = msm_host->dsc;
> > +	u32 reg, intf_width, reg_ctrl, reg_ctrl2;
> > +	u32 slice_per_intf, total_bytes_per_intf;
> > +	u32 pkt_per_line;
> > +	u32 bytes_in_slice;
> > +	u32 eol_byte_num;
> > +
> > +	/* 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);
> > +
> > +	/* If slice_per_pkt is greater than slice_per_intf
> > +	 * then default to 1. This can happen during partial
> > +	 * update.
> > +	 */
> > +	if (slice_per_intf > dsc->drm->slice_count)
> > +		dsc->drm->slice_count = 1;
> > +
> > +	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 = bytes_in_slice * slice_per_intf;
> > +
> > +	eol_byte_num = total_bytes_per_intf % 3;
> > +	pkt_per_line = slice_per_intf / dsc->drm->slice_count;
> > +
> > +	if (is_cmd_mode) /* packet data type */
> > +		reg = DSI_COMMAND_COMPRESSION_MODE_CTRL_STREAM0_DATATYPE(MIPI_DSI_DCS_LONG_WRITE);
> > +	else
> > +		reg = DSI_VIDEO_COMPRESSION_MODE_CTRL_DATATYPE(MIPI_DSI_COMPRESSED_PIXEL_STREAM);
> > +
> > +	/* DSI_VIDEO_COMPRESSION_MODE & DSI_COMMAND_COMPRESSION_MODE
> > +	 * registers have similar offsets, so for below common code use
> > +	 * DSI_VIDEO_COMPRESSION_MODE_XXXX for setting bits
> > +	 */
> > +	reg |= DSI_VIDEO_COMPRESSION_MODE_CTRL_PKT_PER_LINE(pkt_per_line >> 1);
> > +	reg |= DSI_VIDEO_COMPRESSION_MODE_CTRL_EOL_BYTE_NUM(eol_byte_num);
> > +	reg |= DSI_VIDEO_COMPRESSION_MODE_CTRL_EN;
> > +
> > +	if (is_cmd_mode) {
> > +		reg_ctrl = dsi_read(msm_host, REG_DSI_COMMAND_COMPRESSION_MODE_CTRL);
> > +		reg_ctrl2 = dsi_read(msm_host, REG_DSI_COMMAND_COMPRESSION_MODE_CTRL2);
> > +
> > +		reg_ctrl |= reg;
> > +		reg_ctrl2 |= DSI_COMMAND_COMPRESSION_MODE_CTRL2_STREAM0_SLICE_WIDTH(bytes_in_slice);
> > +
> > +		dsi_write(msm_host, REG_DSI_COMMAND_COMPRESSION_MODE_CTRL, reg);
> 
> reg_ctrl, as reported by testing robot

Yes, I did run W=1 check for the patches, with gcc I do not see this
warning :(

I have fixed and will send updated revision shortly

-- 
~Vinod