lkml.org 
[lkml]   [2024]   [Apr]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH v2 3/3] media: amphion: Remove lock in s_ctrl callback
From
Hi Ming Qian,

W dniu 25.04.2024 o 08:50, Ming Qian pisze:
> There is no need to add lock in s_ctrl callback, it has been
> synchronized by the ctrl_handler's lock, otherwise it may led to
> deadlock if driver call v4l2_ctrl_s_ctrl().
>
> Signed-off-by: Ming Qian <ming.qian@nxp.com>
> ---
> drivers/media/platform/amphion/vdec.c | 2 --
> drivers/media/platform/amphion/venc.c | 2 --
> 2 files changed, 4 deletions(-)
>
> diff --git a/drivers/media/platform/amphion/vdec.c b/drivers/media/platform/amphion/vdec.c
> index a57f9f4f3b87..6a38a0fa0e2d 100644
> --- a/drivers/media/platform/amphion/vdec.c
> +++ b/drivers/media/platform/amphion/vdec.c
> @@ -195,7 +195,6 @@ static int vdec_op_s_ctrl(struct v4l2_ctrl *ctrl)
> struct vdec_t *vdec = inst->priv;
> int ret = 0;
>
> - vpu_inst_lock(inst);

I assume that PATCH v2 2/3 might cause the said deadlock to happen?
If so, maybe it would make more sense to make the current patch preceed
PATCH v2 2/3? Otherwise the kernel at PATCH v2 2/3 introduces a potential
deadlock.

Regards,

Andrzej

> switch (ctrl->id) {
> case V4L2_CID_MPEG_VIDEO_DEC_DISPLAY_DELAY_ENABLE:
> vdec->params.display_delay_enable = ctrl->val;
> @@ -207,7 +206,6 @@ static int vdec_op_s_ctrl(struct v4l2_ctrl *ctrl)
> ret = -EINVAL;
> break;
> }
> - vpu_inst_unlock(inst);
>
> return ret;
> }
> diff --git a/drivers/media/platform/amphion/venc.c b/drivers/media/platform/amphion/venc.c
> index cdfaba9d107b..351b4edc8742 100644
> --- a/drivers/media/platform/amphion/venc.c
> +++ b/drivers/media/platform/amphion/venc.c
> @@ -518,7 +518,6 @@ static int venc_op_s_ctrl(struct v4l2_ctrl *ctrl)
> struct venc_t *venc = inst->priv;
> int ret = 0;
>
> - vpu_inst_lock(inst);
> switch (ctrl->id) {
> case V4L2_CID_MPEG_VIDEO_H264_PROFILE:
> venc->params.profile = ctrl->val;
> @@ -579,7 +578,6 @@ static int venc_op_s_ctrl(struct v4l2_ctrl *ctrl)
> ret = -EINVAL;
> break;
> }
> - vpu_inst_unlock(inst);
>
> return ret;
> }


\
 
 \ /
  Last update: 2024-04-29 19:45    [W:0.070 / U:0.812 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site