Messages in this thread | | | Date | Mon, 29 Apr 2024 19:44:59 +0200 | Subject | Re: [PATCH v2 3/3] media: amphion: Remove lock in s_ctrl callback | From | Andrzej Pietrasiewicz <> |
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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; > }
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