Re: [PATCH 3/4] media: aspeed: Correct values for detected timing
From: Joel Stanley <joel@jms.id.au>
Date: 2021-12-22 01:31:18
Also in:
linux-aspeed, linux-media, lkml, openbmc
On Fri, 17 Dec 2021 at 09:54, Jammy Huang [off-list ref] 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
+--+ +-------------------+ +--+
| | | v i d e o | | |
+--+ +-----+ +-----+ +---+
sync+--+
left/top+--------+
right/bottom+----------------------------+
+-------------------+
| v i d e o |
+--+ +-----+ +-----+ +---+
| | | |
+--+ +--+
sync+-------------------------------+
left/top+-----+
right/bottom+-------------------------+This is a good explanation. Can you add detail that relates the names you use here to to the variable names in your patch (or change them to match)?
quoted hunk ↗ jump to hunk
Signed-off-by: Jammy Huang <redacted> --- drivers/media/platform/aspeed-video.c | 27 ++++++++++++++++++++++----- 1 file changed, 22 insertions(+), 5 deletions(-)diff --git a/drivers/media/platform/aspeed-video.c b/drivers/media/platform/aspeed-video.c index 581a4261f9b7..5ad3a20c5bac 100644 --- a/drivers/media/platform/aspeed-video.c +++ b/drivers/media/platform/aspeed-video.c@@ -988,10 +988,20 @@ static void aspeed_video_get_resolution(struct aspeed_video *video) 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);
Would it be clearer if you structured the code like this?
vsync = FIELD_GET(VE_SYNC_STATUS_VSYNC, sync);
vlines = FIELD_GET(VE_MODE_DETECT_V_LINES, mds);
if (det->polarities & V4L2_DV_VSYNC_POS_POL)) {
det->vbackporch = video->frame_top - vsync;
det->vfrontporch = vlines - video->frame_bottom;
det->vsync = vsync;
} else {
det->vbackporch = video->frame_top;
det->vfrontporch = vlines - video->frame_bottom - vsync;
det->vsync = vlines - vsync;
}
quoted hunk ↗ jump to hunk
+ if (det->polarities & V4L2_DV_VSYNC_POS_POL) { + det->vbackporch = video->frame_top - det->vsync; + det->vfrontporch = + FIELD_GET(VE_MODE_DETECT_V_LINES, mds) - + video->frame_bottom; + } else { + det->vsync = FIELD_GET(VE_MODE_DETECT_V_LINES, mds) - + det->vsync; + det->vbackporch = video->frame_top; + det->vfrontporch = + FIELD_GET(VE_MODE_DETECT_V_LINES, mds) - + video->frame_bottom - det->vsync; + } if (video->frame_top > video->frame_bottom) continue;@@ -999,9 +1009,16 @@ static void aspeed_video_get_resolution(struct aspeed_video *video) 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 - det->hsync; + det->hfrontporch = htotal - video->frame_right; + } else { + det->hsync = htotal - det->hsync; + det->hbackporch = video->frame_left; + det->hfrontporch = htotal - video->frame_right - + det->hsync; + } if (video->frame_left > video->frame_right) continue; --2.25.1
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