Commit ac47870f authored by Pengyu Luo's avatar Pengyu Luo Committed by Dmitry Baryshkov
Browse files

drm/msm/dsi: fix hdisplay calculation when programming dsi registers 



Recently, the hdisplay calculation is working for 3:1 compressed ratio
only. If we have a video panel with DSC BPP = 8, and BPC = 10, we still
use the default bits_per_pclk = 24, then we get the wrong hdisplay. We
can draw the conclusion by cross-comparing the calculation with the
calculation in dsi_adjust_pclk_for_compression().

Since CMD mode does not use this, we can remove
!(msm_host->mode_flags & MIPI_DSI_MODE_VIDEO) safely.

Fixes: efcbd6f9 ("drm/msm/dsi: Enable widebus for DSI")
Signed-off-by: default avatarPengyu Luo <mitltlatltl@gmail.com>
Reviewed-by: default avatarDmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/704822/
Link: https://lore.kernel.org/r/20260214105145.105308-1-mitltlatltl@gmail.com


Signed-off-by: default avatarDmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
parent 5886cc8f

drivers/gpu/drm/msm/dsi/dsi_host.c

+8 −6
Original line number Diff line number Diff line
@@ -993,7 +993,7 @@ static void dsi_timing_setup(struct msm_dsi_host *msm_host, bool is_bonded_dsi) 


	if (msm_host->dsc) {

		struct drm_dsc_config *dsc = msm_host->dsc;

		u32 bytes_per_pclk;

		u32 bits_per_pclk;



		/* update dsc params with timing params */

		if (!dsc || !mode->hdisplay || !mode->vdisplay) {
@@ -1015,7 +1015,9 @@ static void dsi_timing_setup(struct msm_dsi_host *msm_host, bool is_bonded_dsi) 


		/*

		 * DPU sends 3 bytes per pclk cycle to DSI. If widebus is

		 * enabled, bus width is extended to 6 bytes.

		 * enabled, MDP always sends out 48-bit compressed data per

		 * pclk and on average, DSI consumes an amount of compressed

		 * data equivalent to the uncompressed pixel depth per pclk.

		 *

		 * Calculate the number of pclks needed to transmit one line of

		 * the compressed data.
@@ -1027,12 +1029,12 @@ static void dsi_timing_setup(struct msm_dsi_host *msm_host, bool is_bonded_dsi) 
		 * unused anyway.

		 */

		h_total -= hdisplay;

		if (wide_bus_enabled && !(msm_host->mode_flags & MIPI_DSI_MODE_VIDEO))

			bytes_per_pclk = 6;

		if (wide_bus_enabled)

			bits_per_pclk = mipi_dsi_pixel_format_to_bpp(msm_host->format);

		else

			bytes_per_pclk = 3;

			bits_per_pclk = 24;



		hdisplay = DIV_ROUND_UP(msm_dsc_get_bytes_per_line(msm_host->dsc), bytes_per_pclk);

		hdisplay = DIV_ROUND_UP(msm_dsc_get_bytes_per_line(msm_host->dsc) * 8, bits_per_pclk);



		h_total += hdisplay;

		ha_end = ha_start + hdisplay;