Hi Jammy, I just want to double check this: I assume you have tested this with the various polarity combinations? I ask because I've never seen this before in any other hardware. The sync and porch values reported by hardware are always independent from the polarity, so that's why I am surprised to see this. Same for the next patch (4/4). Regards, Hans On 12/22/21 09:21, Jammy Huang wrote: > Correct timing's fp/sync/bp value based on the information below. > It should be noticed that the calculation formula should be changed > per sync polarity. > > The sequence of signal: sync - backporch - video data - frontporch > > The following registers start counting from sync's rising edge: > 1. VR090: frame edge's left and right > 2. VR094: frame edge's top and bottom > 3. VR09C: counting from sync's rising edge to falling edge > > [Vertical timing] > +--+ +-------------------+ +--+ > | | | v i d e o | | | > +--+ +-----+ +-----+ +---+ > > vsync+--+ > frame_top+--------+ > frame_bottom+----------------------------+ > > +-------------------+ > | v i d e o | > +--+ +-----+ +-----+ +---+ > | | | | > +--+ +--+ > vsync+-------------------------------+ > frame_top+-----+ > frame_bottom+-------------------------+ > > [Horizontal timing] > +--+ +-------------------+ +--+ > | | | v i d e o | | | > +--+ +-----+ +-----+ +---+ > > hsync+--+ > frame_left+--------+ > frame_right+----------------------------+ > > +-------------------+ > | v i d e o | > +--+ +-----+ +-----+ +---+ > | | | | > +--+ +--+ > hsync+-------------------------------+ > frame_left+-----+ > frame_right+-------------------------+ > > Signed-off-by: Jammy Huang <jammy_huang@xxxxxxxxxxxxxx> > --- > v2: > - Code refined per Joel's suggestion > - Update commit message to have name matching variable > --- > drivers/media/platform/aspeed-video.c | 30 ++++++++++++++++++++------- > 1 file changed, 22 insertions(+), 8 deletions(-) > > diff --git a/drivers/media/platform/aspeed-video.c b/drivers/media/platform/aspeed-video.c > index c241038ee27c..7c50567f5ab0 100644 > --- a/drivers/media/platform/aspeed-video.c > +++ b/drivers/media/platform/aspeed-video.c > @@ -936,7 +936,7 @@ static void aspeed_video_get_resolution(struct aspeed_video *video) > u32 src_lr_edge; > u32 src_tb_edge; > u32 sync; > - u32 htotal; > + u32 htotal, vtotal, vsync, hsync; > struct v4l2_bt_timings *det = &video->detected_timings; > > det->width = MIN_WIDTH; > @@ -983,21 +983,35 @@ static void aspeed_video_get_resolution(struct aspeed_video *video) > mds = aspeed_video_read(video, VE_MODE_DETECT_STATUS); > sync = aspeed_video_read(video, VE_SYNC_STATUS); > htotal = aspeed_video_read(video, VE_H_TOTAL_PIXELS); > + vtotal = FIELD_GET(VE_MODE_DETECT_V_LINES, mds); > + vsync = FIELD_GET(VE_SYNC_STATUS_VSYNC, sync); > + hsync = FIELD_GET(VE_SYNC_STATUS_HSYNC, sync); > > video->frame_bottom = FIELD_GET(VE_SRC_TB_EDGE_DET_BOT, src_tb_edge); > video->frame_top = FIELD_GET(VE_SRC_TB_EDGE_DET_TOP, src_tb_edge); > - det->vfrontporch = video->frame_top; > - det->vbackporch = FIELD_GET(VE_MODE_DETECT_V_LINES, mds) - > - video->frame_bottom; > - det->vsync = FIELD_GET(VE_SYNC_STATUS_VSYNC, sync); > + if (det->polarities & V4L2_DV_VSYNC_POS_POL) { > + det->vbackporch = video->frame_top - vsync; > + det->vfrontporch = vtotal - video->frame_bottom; > + det->vsync = vsync; > + } else { > + det->vbackporch = video->frame_top; > + det->vfrontporch = vsync - video->frame_bottom; > + det->vsync = vtotal - vsync; > + } > if (video->frame_top > video->frame_bottom) > continue; > > video->frame_right = FIELD_GET(VE_SRC_LR_EDGE_DET_RT, src_lr_edge); > video->frame_left = FIELD_GET(VE_SRC_LR_EDGE_DET_LEFT, src_lr_edge); > - det->hfrontporch = video->frame_left; > - det->hbackporch = htotal - video->frame_right; > - det->hsync = FIELD_GET(VE_SYNC_STATUS_HSYNC, sync); > + if (det->polarities & V4L2_DV_HSYNC_POS_POL) { > + det->hbackporch = video->frame_left - hsync; > + det->hfrontporch = htotal - video->frame_right; > + det->hsync = hsync; > + } else { > + det->hbackporch = video->frame_left; > + det->hfrontporch = hsync - video->frame_right; > + det->hsync = htotal - hsync; > + } > if (video->frame_left > video->frame_right) > continue; >