[PATCH 4/4] media: aspeed: Fix timing polarity incorrect
From: Jammy Huang <hidden>
Date: 2021-12-17 09:54:04
Also in:
linux-aspeed, linux-media, lkml, openbmc
Subsystem:
media input infrastructure (v4l/dvb), the rest · Maintainers:
Mauro Carvalho Chehab, Linus Torvalds
This is a workaround for polarity unstable. Sync value get by VR09C counts from sync's rising edge, which means sync's polarity is negative if sync value is bigger than total/2. Signed-off-by: Jammy Huang <redacted> --- drivers/media/platform/aspeed-video.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)
diff --git a/drivers/media/platform/aspeed-video.c b/drivers/media/platform/aspeed-video.c
index 5ad3a20c5bac..f628f69bb7dd 100644
--- a/drivers/media/platform/aspeed-video.c
+++ b/drivers/media/platform/aspeed-video.c@@ -989,6 +989,15 @@ static void aspeed_video_get_resolution(struct aspeed_video *video) video->frame_top = FIELD_GET(VE_SRC_TB_EDGE_DET_TOP, src_tb_edge); det->vsync = FIELD_GET(VE_SYNC_STATUS_VSYNC, sync); + /* + * Workaround for polarity detection + * Use sync(VR098) counts from sync's rising edge till falling + * edge to tell sync polarity. + */ + if (det->vsync > (FIELD_GET(VE_MODE_DETECT_V_LINES, mds) >> 1)) + det->polarities &= ~V4L2_DV_VSYNC_POS_POL; + else + det->polarities |= V4L2_DV_VSYNC_POS_POL; if (det->polarities & V4L2_DV_VSYNC_POS_POL) { det->vbackporch = video->frame_top - det->vsync; det->vfrontporch =
@@ -1010,6 +1019,15 @@ static void aspeed_video_get_resolution(struct aspeed_video *video) video->frame_left = FIELD_GET(VE_SRC_LR_EDGE_DET_LEFT, src_lr_edge); det->hsync = FIELD_GET(VE_SYNC_STATUS_HSYNC, sync); + /* + * Workaround for polarity detection + * Use sync(VR098) counts from sync's rising edge till falling + * edge to tell sync polarity. + */ + if (det->hsync > (htotal >> 1)) + det->polarities &= ~V4L2_DV_HSYNC_POS_POL; + else + det->polarities |= V4L2_DV_HSYNC_POS_POL; if (det->polarities & V4L2_DV_HSYNC_POS_POL) { det->hbackporch = video->frame_left - det->hsync; det->hfrontporch = htotal - video->frame_right;
--
2.25.1
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