Re: [PATCH 1/2] media: s5p-mfc: convert drivers to use the new vb2_queue dev field

[Javier Martinez Canillas]

Hello Pankaj,

On 12/16/2016 08:48 AM, Pankaj Dubey wrote:
> From: Smitha T Murthy <smitha.t@xxxxxxxxxxx>
> 
> commit 2548fee63d9e ("[media] media/platform: convert drivers to use the new
> vb2_queue dev field") has missed to set dev pointer of vb2_queue which will be
> used in reqbufs of mfc driver. Without this change following error is observed:
> 
> ---------------------------------------------------------------
> V4L2 Codec decoding example application
> Kamil Debski <k.debski@xxxxxxxxxxx>
> Copyright 2012 Samsung Electronics Co., Ltd.
> 
> Opening MFC.
> (mfc.c:mfc_open:58): MFC Info (/dev/video0): driver="s5p-mfc" \
> bus_info="platform:12c30000.mfc0" card="s5p-mfc-dec" fd=0x4[
> 42.339165] Remapping memory failed, error: -6
> 
> MFC Open Success.
> (main.c:main:711): Successfully opened all necessary files and devices
> (mfc.c:mfc_dec_setup_output:103): Setup MFC decoding OUTPUT buffer \
> size=4194304 (requested=4194304)
> (mfc.c:mfc_dec_setup_output:120): Number of MFC OUTPUT buffers is 2 \
> (requested 2)
> 
> [App] Out buf phy : 0x00000000, virt : 0xffffffff
> Output Length is = 0x300000
> Error (mfc.c:mfc_dec_setup_output:145): Failed to MMAP MFC OUTPUT buffer
> -------------------------------------------------------
> 

On which kernel version did you face this issue?

> Signed-off-by: Smitha T Murthy <smitha.t@xxxxxxxxxxx>
> [pankaj.dubey: debugging issue and formatting commit message]
> Signed-off-by: Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx>
> ---
>  drivers/media/platform/s5p-mfc/s5p_mfc.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc.c b/drivers/media/platform/s5p-mfc/s5p_mfc.c
> index 0a5b8f5..6ea8246 100644
> --- a/drivers/media/platform/s5p-mfc/s5p_mfc.c
> +++ b/drivers/media/platform/s5p-mfc/s5p_mfc.c
> @@ -838,6 +838,7 @@ static int s5p_mfc_open(struct file *file)
>  	q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
>  	q->drv_priv = &ctx->fh;
>  	q->lock = &dev->mfc_mutex;
> +	q->dev = &dev->plat_dev->dev;
>  	if (vdev == dev->vfd_dec) {
>  		q->io_modes = VB2_MMAP;
>  		q->ops = get_dec_queue_ops();
> @@ -861,6 +862,7 @@ static int s5p_mfc_open(struct file *file)
>  	q->io_modes = VB2_MMAP;
>  	q->drv_priv = &ctx->fh;
>  	q->lock = &dev->mfc_mutex;
> +	q->dev = &dev->plat_dev->dev;
>  	if (vdev == dev->vfd_dec) {
>  		q->io_modes = VB2_MMAP;
>  		q->ops = get_dec_queue_ops();
>

Please correct me if I'm wrong, but AFAIU this shouldn't be needed in
the s5p-mfc driver since the videobuf2 core either uses the vb2_queue
.dev field or the vb2_queue .alloc_devs. And the latter is set in the
s5p_mfc_queue_setup() function, so the .dev field shouldn't be used.

Best regards,
-- 
Javier Martinez Canillas
Open Source Group
Samsung Research America