2021-12-17 09:54:04

by Jammy Huang

Subject: [PATCH 4/4] media: aspeed: Fix timing polarity incorrect

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 <[email protected]>
---
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

2021-12-22 01:22:53

by Joel Stanley

Subject: Re: [PATCH 4/4] media: aspeed: Fix timing polarity incorrect

On Fri, 17 Dec 2021 at 09:54, Jammy Huang <[email protected]> wrote:
>
> 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 <[email protected]>
> ---
> 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))

Are you right shifting as this is the value / 2? I think it's clearer
to write / 2 instead of >> 1.

Mention in the comment that this is a workaround for when the sync
value is larger than half.

> + 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
>

2021-12-22 06:10:42

by Jammy Huang

Subject: Re: [PATCH 4/4] media: aspeed: Fix timing polarity incorrect

Hi Joel,

OK, I will update in next patch as you advised.
Thanks for your review.

On 2021/12/22 上午 09:22, Joel Stanley wrote:
> On Fri, 17 Dec 2021 at 09:54, Jammy Huang <[email protected]> wrote:
>> 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 <[email protected]>
>> ---
>> 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))
> Are you right shifting as this is the value / 2? I think it's clearer
> to write / 2 instead of >> 1.
>
> Mention in the comment that this is a workaround for when the sync
> value is larger than half.
>
>> + 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
>>
--
Best Regards
Jammy