[v14,26/56] media: i2c: video-i2c: Stop direct calls to queue num_buffers field

Message ID 20231031163104.112469-27-benjamin.gaignard@collabora.com
State New
Headers
Series Add DELETE_BUF ioctl |

Commit Message

Benjamin Gaignard Oct. 31, 2023, 4:30 p.m. UTC
  Use vb2_get_num_buffers() to avoid using queue num_buffers field directly.
This allows us to change how the number of buffers is computed in the
future.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
CC: Matt Ranostay <matt.ranostay@konsulko.com>
---
 drivers/media/i2c/video-i2c.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
  

Comments

Andrzej Pietrasiewicz Nov. 9, 2023, 10:18 a.m. UTC | #1
Hi Benjamin,

W dniu 31.10.2023 o 17:30, Benjamin Gaignard pisze:
> Use vb2_get_num_buffers() to avoid using queue num_buffers field directly.
> This allows us to change how the number of buffers is computed in the
> future.
> 
> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
> CC: Matt Ranostay <matt.ranostay@konsulko.com>
> ---
>   drivers/media/i2c/video-i2c.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/i2c/video-i2c.c b/drivers/media/i2c/video-i2c.c
> index 178bd06cc2ed..ebf2ac98a068 100644
> --- a/drivers/media/i2c/video-i2c.c
> +++ b/drivers/media/i2c/video-i2c.c
> @@ -405,9 +405,10 @@ static int queue_setup(struct vb2_queue *vq,
>   {
>   	struct video_i2c_data *data = vb2_get_drv_priv(vq);
>   	unsigned int size = data->chip->buffer_size;
> +	unsigned int q_num_bufs = vb2_get_num_buffers(vq);
>   
> -	if (vq->num_buffers + *nbuffers < 2)
> -		*nbuffers = 2;
> +	if (q_num_bufs + *nbuffers < 2)
> +		*nbuffers = 2 - q_num_bufs;

This actually changes the logic. Maybe it has already been discussed and
the result of that discussion is this change in logic? Looking at other
drivers *nbuffers = 2 - q_num_bufs; seems the right thing to do.
But then at least the commit message body IMO should mention this change.
Or, preferably, the change in logic should be a separate patch to be applied
before this one.

Regards,

Andrzej

>   
>   	if (*nplanes)
>   		return sizes[0] < size ? -EINVAL : 0;
  
Benjamin Gaignard Nov. 9, 2023, 10:26 a.m. UTC | #2
Le 09/11/2023 à 11:18, Andrzej Pietrasiewicz a écrit :
> Hi Benjamin,
>
> W dniu 31.10.2023 o 17:30, Benjamin Gaignard pisze:
>> Use vb2_get_num_buffers() to avoid using queue num_buffers field 
>> directly.
>> This allows us to change how the number of buffers is computed in the
>> future.
>>
>> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
>> CC: Matt Ranostay <matt.ranostay@konsulko.com>
>> ---
>>   drivers/media/i2c/video-i2c.c | 5 +++--
>>   1 file changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/media/i2c/video-i2c.c 
>> b/drivers/media/i2c/video-i2c.c
>> index 178bd06cc2ed..ebf2ac98a068 100644
>> --- a/drivers/media/i2c/video-i2c.c
>> +++ b/drivers/media/i2c/video-i2c.c
>> @@ -405,9 +405,10 @@ static int queue_setup(struct vb2_queue *vq,
>>   {
>>       struct video_i2c_data *data = vb2_get_drv_priv(vq);
>>       unsigned int size = data->chip->buffer_size;
>> +    unsigned int q_num_bufs = vb2_get_num_buffers(vq);
>>   -    if (vq->num_buffers + *nbuffers < 2)
>> -        *nbuffers = 2;
>> +    if (q_num_bufs + *nbuffers < 2)
>> +        *nbuffers = 2 - q_num_bufs;
>
> This actually changes the logic. Maybe it has already been discussed and
> the result of that discussion is this change in logic? Looking at other
> drivers *nbuffers = 2 - q_num_bufs; seems the right thing to do.
> But then at least the commit message body IMO should mention this change.
> Or, preferably, the change in logic should be a separate patch to be 
> applied
> before this one.

I will add word about that in the commit message.
Thanks.
Benjamin

>
> Regards,
>
> Andrzej
>
>>         if (*nplanes)
>>           return sizes[0] < size ? -EINVAL : 0;
>
> _______________________________________________
> Kernel mailing list -- kernel@mailman.collabora.com
> To unsubscribe send an email to kernel-leave@mailman.collabora.com
  

Patch

diff --git a/drivers/media/i2c/video-i2c.c b/drivers/media/i2c/video-i2c.c
index 178bd06cc2ed..ebf2ac98a068 100644
--- a/drivers/media/i2c/video-i2c.c
+++ b/drivers/media/i2c/video-i2c.c
@@ -405,9 +405,10 @@  static int queue_setup(struct vb2_queue *vq,
 {
 	struct video_i2c_data *data = vb2_get_drv_priv(vq);
 	unsigned int size = data->chip->buffer_size;
+	unsigned int q_num_bufs = vb2_get_num_buffers(vq);
 
-	if (vq->num_buffers + *nbuffers < 2)
-		*nbuffers = 2;
+	if (q_num_bufs + *nbuffers < 2)
+		*nbuffers = 2 - q_num_bufs;
 
 	if (*nplanes)
 		return sizes[0] < size ? -EINVAL : 0;