[PATCH v1 2/2] drm/stm: ltdc: Solve issue on pixel clock & data enable polarity

Yannick Fertré yannick.fertre at st.com
Mon Sep 24 11:36:21 UTC 2018


Wrong flags used for set the pixel clock & data enable polarities.
Add trace for polarities of hsync, vsync, data enabled & pixel clock.

Signed-off-by: Yannick Fertré <yannick.fertre at st.com>
---
 drivers/gpu/drm/stm/ltdc.c | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
index 808d9fb..f671abc 100644
--- a/drivers/gpu/drm/stm/ltdc.c
+++ b/drivers/gpu/drm/stm/ltdc.c
@@ -517,7 +517,7 @@ static void ltdc_crtc_mode_set_nofb(struct drm_crtc *crtc)
 	struct videomode vm;
 	u32 hsync, vsync, accum_hbp, accum_vbp, accum_act_w, accum_act_h;
 	u32 total_width, total_height;
-	u32 val;
+	u32 val = 0;
 
 	drm_display_mode_to_videomode(mode, &vm);
 
@@ -538,7 +538,22 @@ static void ltdc_crtc_mode_set_nofb(struct drm_crtc *crtc)
 	total_height = accum_act_h + vm.vfront_porch;
 
 	/* Configures the HS, VS, DE and PC polarities. Default Active Low */
-	val = 0;
+	if (vm.flags & DISPLAY_FLAGS_HSYNC_LOW)
+		DRM_DEBUG_DRIVER("Horizontal Synchronization polarity is active low");
+	if (vm.flags & DISPLAY_FLAGS_HSYNC_HIGH)
+		DRM_DEBUG_DRIVER("Horizontal Synchronization polarity is active high");
+	if (vm.flags & DISPLAY_FLAGS_VSYNC_LOW)
+		DRM_DEBUG_DRIVER("Vertical Synchronization polarity is active low");
+	if (vm.flags & DISPLAY_FLAGS_VSYNC_HIGH)
+		DRM_DEBUG_DRIVER("Vertical Synchronization polarity is active high");
+	if (vm.flags & DISPLAY_FLAGS_DE_LOW)
+		DRM_DEBUG_DRIVER("Data Enable polarity is active low");
+	if (vm.flags & DISPLAY_FLAGS_DE_HIGH)
+		DRM_DEBUG_DRIVER("Data Enable polarity is active high");
+	if (vm.flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE)
+		DRM_DEBUG_DRIVER("Pixel clock polarity is active low");
+	if (vm.flags & DISPLAY_FLAGS_PIXDATA_POSEDGE)
+		DRM_DEBUG_DRIVER("Pixel clock polarity is active high");
 
 	if (vm.flags & DISPLAY_FLAGS_HSYNC_HIGH)
 		val |= GCR_HSPOL;
@@ -546,10 +561,10 @@ static void ltdc_crtc_mode_set_nofb(struct drm_crtc *crtc)
 	if (vm.flags & DISPLAY_FLAGS_VSYNC_HIGH)
 		val |= GCR_VSPOL;
 
-	if (vm.flags & DISPLAY_FLAGS_DE_HIGH)
+	if (vm.flags & DISPLAY_FLAGS_DE_LOW)
 		val |= GCR_DEPOL;
 
-	if (vm.flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE)
+	if (vm.flags & DISPLAY_FLAGS_PIXDATA_POSEDGE)
 		val |= GCR_PCPOL;
 
 	reg_update_bits(ldev->regs, LTDC_GCR,
-- 
2.7.4



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