diff mbox series

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

Message ID 20211217095403.2618-5-jammy_huang@aspeedtech.com (mailing list archive)
State New, archived
Headers show
Series Correct timing report | expand

Commit Message

Jammy Huang Dec. 17, 2021, 9:54 a.m. UTC
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 <jammy_huang@aspeedtech.com>
---
 drivers/media/platform/aspeed-video.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

Comments

Joel Stanley Dec. 22, 2021, 1:22 a.m. UTC | #1
On Fri, 17 Dec 2021 at 09:54, Jammy Huang <jammy_huang@aspeedtech.com> 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 <jammy_huang@aspeedtech.com>
> ---
>  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
>
Jammy Huang Dec. 22, 2021, 6:10 a.m. UTC | #2
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 <jammy_huang@aspeedtech.com> 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 <jammy_huang@aspeedtech.com>
>> ---
>>   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
>>
diff mbox series

Patch

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;