Re: [PATCH v5 6/6] drm/msm/dsi: add a comment to explain pkt_per_line encoding

[Jessica Zhang <quic_jesszhan@quicinc.com>]

On 5/27/2024 7:21 AM, Jun Nie wrote:
> From: Jonathan Marek <jonathan@marek.ca>
> 
> Make it clear why the pkt_per_line value is being "divided by 2".
> 
> Signed-off-by: Jonathan Marek <jonathan@marek.ca>
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Signed-off-by: Jun Nie <jun.nie@linaro.org>

Hi Jun,

Reviewed-by: Jessica Zhang <quic_jesszhan@quicinc.com>

Thanks,

Jessica Zhang

> ---
>   drivers/gpu/drm/msm/dsi/dsi_host.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
> index 7252d36687e6..4768cff08381 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi_host.c
> +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
> @@ -885,7 +885,11 @@ static void dsi_update_dsc_timing(struct msm_dsi_host *msm_host, bool is_cmd_mod
>   	/* 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
> +	 *
> +	 * pkt_per_line is log2 encoded, >>1 works for supported values (1,2,4)
>   	 */
> +	if (pkt_per_line > 4)
> +		drm_warn_once(msm_host->dev, "pkt_per_line too big");
>   	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;
> 
> -- 
> 2.34.1
>