[PATCH v2 15/20] drm/msm/dp: Flush VSC updates when leaving YUV420

[Xilin Wu]

Peripheral flush is currently requested only for the new YUV420 mode.
Returning to RGB also changes SDP state and must remove the old VSC
packet rather than leaving its enable bits set.

Track whether either stream needs VSC and request peripheral flush for
both enabling and removing it. Explicitly disable VSC for RGB, and write
the packet payload before enabling transmission. Retain the existing
hardware-specific SDP update mechanism.

Assisted-by: LLM
Signed-off-by: Xilin Wu <sophon@xxxxxxxxx>
---
 drivers/gpu/drm/msm/dp/dp_display.c | 7 ++++++-
 drivers/gpu/drm/msm/dp/dp_panel.c   | 6 ++++--
 drivers/gpu/drm/msm/dp/dp_panel.h   | 1 +
 3 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index 1f9595ff5fd9..486348113b8a 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -691,6 +691,8 @@ static int msm_dp_display_set_mode(struct msm_dp *msm_dp_display,
 	else
 		bpp = state->bpp;
 
+	msm_dp_panel->sdp_needs_flush = msm_dp_panel->msm_dp_mode.out_fmt_is_yuv_420 ||
+		drm_mode_is_420_only(&msm_dp_panel->connector->display_info, adjusted_mode);
 	msm_dp_panel_init_panel_info(msm_dp_panel, adjusted_mode, bpp ? bpp : 24);
 
 	/* populate wide_bus_support to different layers */
@@ -1557,7 +1559,10 @@ void __exit msm_dp_unregister(void)
 bool msm_dp_needs_periph_flush(const struct msm_dp *msm_dp_display,
 			       const struct drm_display_mode *mode)
 {
-	return drm_mode_is_420_only(&msm_dp_display->connector->display_info, mode);
+	struct msm_dp_display_private *dp = container_of(msm_dp_display,
+					struct msm_dp_display_private, msm_dp_display);
+
+	return dp->panel->sdp_needs_flush;
 }
 
 bool msm_dp_wide_bus_available(const struct msm_dp *msm_dp_display)
diff --git a/drivers/gpu/drm/msm/dp/dp_panel.c b/drivers/gpu/drm/msm/dp/dp_panel.c
index af05441bc32a..026074cafc88 100644
--- a/drivers/gpu/drm/msm/dp/dp_panel.c
+++ b/drivers/gpu/drm/msm/dp/dp_panel.c
@@ -526,14 +526,14 @@ void msm_dp_panel_enable_vsc_sdp(struct msm_dp_panel *msm_dp_panel, struct dp_sd
 	cfg2 = msm_dp_read_link(panel, MMSS_DP_SDP_CFG2);
 	misc = msm_dp_read_link(panel, REG_DP_MISC1_MISC0);
 
+	msm_dp_panel_send_sdp(panel, vsc_sdp, MMSS_DP_GENERIC0_0);
+
 	cfg |= GEN0_SDP_EN;
 	msm_dp_write_link(panel, MMSS_DP_SDP_CFG, cfg);
 
 	cfg2 |= GENERIC0_SDPSIZE_VALID;
 	msm_dp_write_link(panel, MMSS_DP_SDP_CFG2, cfg2);
 
-	msm_dp_panel_send_sdp(panel, vsc_sdp, MMSS_DP_GENERIC0_0);
-
 	/* indicates presence of VSC (BIT(6) of MISC1) */
 	misc |= DP_MISC1_VSC_SDP;
 
@@ -686,6 +686,8 @@ int msm_dp_panel_timing_cfg(struct msm_dp_panel *msm_dp_panel, bool wide_bus_en)
 
 	if (msm_dp_panel->msm_dp_mode.out_fmt_is_yuv_420)
 		msm_dp_panel_setup_vsc_sdp_yuv_420(msm_dp_panel);
+	else
+		msm_dp_panel_disable_vsc_sdp(msm_dp_panel);
 
 	panel->panel_on = true;
 
diff --git a/drivers/gpu/drm/msm/dp/dp_panel.h b/drivers/gpu/drm/msm/dp/dp_panel.h
index a5cb8a4a9498..31752895f124 100644
--- a/drivers/gpu/drm/msm/dp/dp_panel.h
+++ b/drivers/gpu/drm/msm/dp/dp_panel.h
@@ -42,6 +42,7 @@ struct msm_dp_panel {
 	bool link_caps_valid;
 	/* All capability reads completed; eDP can reuse the full cache. */
 	bool caps_cached;
+	bool sdp_needs_flush;
 	u32 hw_revision;
 
 	u32 max_bw_code;

-- 
2.56.0