diff mbox series

[v2,4/4] media: aspeed: Fix timing polarity incorrect

Message ID 20211222082139.26933-5-jammy_huang@aspeedtech.com (mailing list archive)
State New, archived
Headers show
Series Correct timing report | expand

Commit Message

Jammy Huang Dec. 22, 2021, 8:21 a.m. UTC
This is a workaround for sync 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>
---
 v2:
  - Use 'total/2' rather than 'total<<1'
  - Update comment
---
 drivers/media/platform/aspeed-video.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

Comments

Hans Verkuil Jan. 21, 2022, 7:30 a.m. UTC | #1
On 12/22/21 09:21, Jammy Huang wrote:
> This is a workaround for sync 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.

Do you have an example of such a format, or is this mostly theoretical?

Either provide the example or make a note that it is theoretical.

Regards,

	Hans

> 
> Signed-off-by: Jammy Huang <jammy_huang@aspeedtech.com>
> ---
>  v2:
>   - Use 'total/2' rather than 'total<<1'
>   - Update comment
> ---
>  drivers/media/platform/aspeed-video.c | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
> 
> diff --git a/drivers/media/platform/aspeed-video.c b/drivers/media/platform/aspeed-video.c
> index 7c50567f5ab0..c3e3343d91e1 100644
> --- a/drivers/media/platform/aspeed-video.c
> +++ b/drivers/media/platform/aspeed-video.c
> @@ -989,6 +989,16 @@ static void aspeed_video_get_resolution(struct aspeed_video *video)
>  
>  		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);
> +
> +		/*
> +		 * This is a workaround for polarity detection when the sync
> +		 * value is larger than half.
> +		 */
> +		if (vsync > (vtotal / 2))
> +			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 - vsync;
>  			det->vfrontporch = vtotal - video->frame_bottom;
> @@ -1003,6 +1013,16 @@ static void aspeed_video_get_resolution(struct aspeed_video *video)
>  
>  		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);
> +
> +		/*
> +		 * This is a workaround for polarity detection when the sync
> +		 * value is larger than half.
> +		 */
> +		if (hsync > (htotal / 2))
> +			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 - hsync;
>  			det->hfrontporch = htotal - video->frame_right;
Jammy Huang Jan. 24, 2022, 2:29 a.m. UTC | #2
On 2022/1/21 下午 03:30, Hans Verkuil wrote:
> On 12/22/21 09:21, Jammy Huang wrote:
>> This is a workaround for sync 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.
> Do you have an example of such a format, or is this mostly theoretical?
>
> Either provide the example or make a note that it is theoretical.

OK, I will update an example in next patch. Let me explain first.

This is a must-be result. Please refer to the graph below as I sent in 
3/4 of this
series. For negative sync, sync width equals to back porch + data enable 
+ front porch.
Thus, sync would be bigger than 90% of total in most cases.

                   +-------------------+
                   |    v i d e o      |
       +--+  +-----+                   +-----+  +---+
          |  |                               |  |
          +--+                               +--+
        vsync+-------------------------------+
    frame_top+-----+
frame_bottom+-------------------------+


Following registers are what I got for 1920x1200@60.

1e700090: 07ee206f 04c9001a c4d3efff 04cc001f

1e7000a0: 0000081f 00000000 00000000 00000000

vertical total = 0x4D3 (VR098[27:16]) = 1235
vertical sync = 0x4CC (VR09C[27:16]) = 1228

>
> Regards,
>
> 	Hans
>
>> Signed-off-by: Jammy Huang <jammy_huang@aspeedtech.com>
>> ---
>>   v2:
>>    - Use 'total/2' rather than 'total<<1'
>>    - Update comment
>> ---
>>   drivers/media/platform/aspeed-video.c | 20 ++++++++++++++++++++
>>   1 file changed, 20 insertions(+)
>>
>> diff --git a/drivers/media/platform/aspeed-video.c b/drivers/media/platform/aspeed-video.c
>> index 7c50567f5ab0..c3e3343d91e1 100644
>> --- a/drivers/media/platform/aspeed-video.c
>> +++ b/drivers/media/platform/aspeed-video.c
>> @@ -989,6 +989,16 @@ static void aspeed_video_get_resolution(struct aspeed_video *video)
>>   
>>   		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);
>> +
>> +		/*
>> +		 * This is a workaround for polarity detection when the sync
>> +		 * value is larger than half.
>> +		 */
>> +		if (vsync > (vtotal / 2))
>> +			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 - vsync;
>>   			det->vfrontporch = vtotal - video->frame_bottom;
>> @@ -1003,6 +1013,16 @@ static void aspeed_video_get_resolution(struct aspeed_video *video)
>>   
>>   		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);
>> +
>> +		/*
>> +		 * This is a workaround for polarity detection when the sync
>> +		 * value is larger than half.
>> +		 */
>> +		if (hsync > (htotal / 2))
>> +			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 - hsync;
>>   			det->hfrontporch = htotal - video->frame_right;
Hans Verkuil Jan. 24, 2022, 10:22 a.m. UTC | #3
On 24/01/2022 03:29, Jammy Huang wrote:
> 
> On 2022/1/21 下午 03:30, Hans Verkuil wrote:
>> On 12/22/21 09:21, Jammy Huang wrote:
>>> This is a workaround for sync 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.
>> Do you have an example of such a format, or is this mostly theoretical?
>>
>> Either provide the example or make a note that it is theoretical.
> 
> OK, I will update an example in next patch. Let me explain first.
> 
> This is a must-be result. Please refer to the graph below as I sent in 3/4 of this
> series. For negative sync, sync width equals to back porch + data enable + front porch.
> Thus, sync would be bigger than 90% of total in most cases.

Right, I suspected that might be the case.

I think it would be better to combine patches 3 and 4 into a single
patch, since they are closely related and it is actually easier to
understand if it's just a single patch.

Regards,

	Hans

> 
>                   +-------------------+
>                   |    v i d e o      |
>       +--+  +-----+                   +-----+  +---+
>          |  |                               |  |
>          +--+                               +--+
>        vsync+-------------------------------+
>    frame_top+-----+
> frame_bottom+-------------------------+
> 
> 
> Following registers are what I got for 1920x1200@60.
> 
> 1e700090: 07ee206f 04c9001a c4d3efff 04cc001f
> 
> 1e7000a0: 0000081f 00000000 00000000 00000000
> 
> vertical total = 0x4D3 (VR098[27:16]) = 1235
> vertical sync = 0x4CC (VR09C[27:16]) = 1228
> 
>>
>> Regards,
>>
>>     Hans
>>
>>> Signed-off-by: Jammy Huang <jammy_huang@aspeedtech.com>
>>> ---
>>>   v2:
>>>    - Use 'total/2' rather than 'total<<1'
>>>    - Update comment
>>> ---
>>>   drivers/media/platform/aspeed-video.c | 20 ++++++++++++++++++++
>>>   1 file changed, 20 insertions(+)
>>>
>>> diff --git a/drivers/media/platform/aspeed-video.c b/drivers/media/platform/aspeed-video.c
>>> index 7c50567f5ab0..c3e3343d91e1 100644
>>> --- a/drivers/media/platform/aspeed-video.c
>>> +++ b/drivers/media/platform/aspeed-video.c
>>> @@ -989,6 +989,16 @@ static void aspeed_video_get_resolution(struct aspeed_video *video)
>>>             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);
>>> +
>>> +        /*
>>> +         * This is a workaround for polarity detection when the sync
>>> +         * value is larger than half.
>>> +         */
>>> +        if (vsync > (vtotal / 2))
>>> +            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 - vsync;
>>>               det->vfrontporch = vtotal - video->frame_bottom;
>>> @@ -1003,6 +1013,16 @@ static void aspeed_video_get_resolution(struct aspeed_video *video)
>>>             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);
>>> +
>>> +        /*
>>> +         * This is a workaround for polarity detection when the sync
>>> +         * value is larger than half.
>>> +         */
>>> +        if (hsync > (htotal / 2))
>>> +            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 - hsync;
>>>               det->hfrontporch = htotal - video->frame_right;
>
Jammy Huang Jan. 25, 2022, 1:37 a.m. UTC | #4
On 2022/1/24 下午 06:22, Hans Verkuil wrote:
> On 24/01/2022 03:29, Jammy Huang wrote:
>> On 2022/1/21 下午 03:30, Hans Verkuil wrote:
>>> On 12/22/21 09:21, Jammy Huang wrote:
>>>> This is a workaround for sync 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.
>>> Do you have an example of such a format, or is this mostly theoretical?
>>>
>>> Either provide the example or make a note that it is theoretical.
>> OK, I will update an example in next patch. Let me explain first.
>>
>> This is a must-be result. Please refer to the graph below as I sent in 3/4 of this
>> series. For negative sync, sync width equals to back porch + data enable + front porch.
>> Thus, sync would be bigger than 90% of total in most cases.
> Right, I suspected that might be the case.
>
> I think it would be better to combine patches 3 and 4 into a single
> patch, since they are closely related and it is actually easier to
> understand if it's just a single patch.
OK, I will combine 3/4 into a single patch in next series.
Thanks.

Best Regards,

         Jammy
>
> Regards,
>
> 	Hans
>
>>                    +-------------------+
>>                    |    v i d e o      |
>>        +--+  +-----+                   +-----+  +---+
>>           |  |                               |  |
>>           +--+                               +--+
>>         vsync+-------------------------------+
>>     frame_top+-----+
>> frame_bottom+-------------------------+
>>
>>
>> Following registers are what I got for 1920x1200@60.
>>
>> 1e700090: 07ee206f 04c9001a c4d3efff 04cc001f
>>
>> 1e7000a0: 0000081f 00000000 00000000 00000000
>>
>> vertical total = 0x4D3 (VR098[27:16]) = 1235
>> vertical sync = 0x4CC (VR09C[27:16]) = 1228
>>
>>> Regards,
>>>
>>>      Hans
>>>
>>>> Signed-off-by: Jammy Huang <jammy_huang@aspeedtech.com>
>>>> ---
>>>>    v2:
>>>>     - Use 'total/2' rather than 'total<<1'
>>>>     - Update comment
>>>> ---
>>>>    drivers/media/platform/aspeed-video.c | 20 ++++++++++++++++++++
>>>>    1 file changed, 20 insertions(+)
>>>>
>>>> diff --git a/drivers/media/platform/aspeed-video.c b/drivers/media/platform/aspeed-video.c
>>>> index 7c50567f5ab0..c3e3343d91e1 100644
>>>> --- a/drivers/media/platform/aspeed-video.c
>>>> +++ b/drivers/media/platform/aspeed-video.c
>>>> @@ -989,6 +989,16 @@ static void aspeed_video_get_resolution(struct aspeed_video *video)
>>>>              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);
>>>> +
>>>> +        /*
>>>> +         * This is a workaround for polarity detection when the sync
>>>> +         * value is larger than half.
>>>> +         */
>>>> +        if (vsync > (vtotal / 2))
>>>> +            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 - vsync;
>>>>                det->vfrontporch = vtotal - video->frame_bottom;
>>>> @@ -1003,6 +1013,16 @@ static void aspeed_video_get_resolution(struct aspeed_video *video)
>>>>              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);
>>>> +
>>>> +        /*
>>>> +         * This is a workaround for polarity detection when the sync
>>>> +         * value is larger than half.
>>>> +         */
>>>> +        if (hsync > (htotal / 2))
>>>> +            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 - hsync;
>>>>                det->hfrontporch = htotal - video->frame_right;
diff mbox series

Patch

diff --git a/drivers/media/platform/aspeed-video.c b/drivers/media/platform/aspeed-video.c
index 7c50567f5ab0..c3e3343d91e1 100644
--- a/drivers/media/platform/aspeed-video.c
+++ b/drivers/media/platform/aspeed-video.c
@@ -989,6 +989,16 @@  static void aspeed_video_get_resolution(struct aspeed_video *video)
 
 		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);
+
+		/*
+		 * This is a workaround for polarity detection when the sync
+		 * value is larger than half.
+		 */
+		if (vsync > (vtotal / 2))
+			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 - vsync;
 			det->vfrontporch = vtotal - video->frame_bottom;
@@ -1003,6 +1013,16 @@  static void aspeed_video_get_resolution(struct aspeed_video *video)
 
 		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);
+
+		/*
+		 * This is a workaround for polarity detection when the sync
+		 * value is larger than half.
+		 */
+		if (hsync > (htotal / 2))
+			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 - hsync;
 			det->hfrontporch = htotal - video->frame_right;