Linux-ARM-Kernel Archive on lore.kernel.org

* Re: [RFC PATCH V2 4/4] platform: mtk-isp: Add Mediatek FD driver
From: Tomasz Figa @ 2019-09-04 13:12 UTC (permalink / raw)
  To: Jerry-ch Chen
  Cc: devicetree@vger.kernel.org, Sean Cheng (鄭昇弘),
	laurent.pinchart+renesas@ideasonboard.com,
	Rynn Wu (吳育恩), srv_heupstream,
	Po-Yang Huang (黃柏陽), mchehab@kernel.org,
	suleiman@chromium.org, shik@chromium.org,
	Jungo Lin (林明俊),
	Sj Huang (黃信璋), yuzhao@chromium.org,
	linux-mediatek@lists.infradead.org, zwisler@chromium.org,
	matthias.bgg@gmail.com, Christie Yu (游雅惠),
	Frederic Chen (陳俊元), hans.verkuil@cisco.com,
	linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org
In-Reply-To: <1567589188.22453.24.camel@mtksdccf07>

On Wed, Sep 4, 2019 at 6:26 PM Jerry-ch Chen <Jerry-ch.Chen@mediatek.com> wrote:
>
> Hi Tomasz,
>
> On Wed, 2019-09-04 at 17:03 +0800, Tomasz Figa wrote:
> > On Wed, Sep 4, 2019 at 6:02 PM Jerry-ch Chen <Jerry-ch.Chen@mediatek.com> wrote:
> > >
> > > Hi Tomasz,
> > >
> > > On Wed, 2019-09-04 at 16:25 +0800, Tomasz Figa wrote:
> > > > On Wed, Sep 4, 2019 at 5:09 PM Jerry-ch Chen <Jerry-ch.Chen@mediatek.com> wrote:
> > > > >
> > > > > Hi Tomasz,
> > > > >
> > > > > On Wed, 2019-09-04 at 14:34 +0800, Tomasz Figa wrote:
> > > > > > On Wed, Sep 4, 2019 at 3:09 PM Jerry-ch Chen <Jerry-ch.Chen@mediatek.com> wrote:
> > > > > > >
> > > > > > > Hi Tomasz,
> > > > > > >
> > > > > > > On Wed, 2019-09-04 at 12:15 +0800, Tomasz Figa wrote:
> > > > > > > > On Wed, Sep 4, 2019 at 12:38 PM Jerry-ch Chen
> > > > > > > > <Jerry-ch.Chen@mediatek.com> wrote:
> > > > > > > > >
> > > > > > > > > Hi Tomasz,
> > > > > > > > >
> > > > > > > > > On Tue, 2019-09-03 at 20:05 +0800, Tomasz Figa wrote:
> > > > > > > > > > On Tue, Sep 3, 2019 at 8:46 PM Jerry-ch Chen <Jerry-ch.Chen@mediatek.com> wrote:
> > > > > > > > > > >
> > > > > > > > > > > Hi Tomasz,
> > > > > > > > > > >
> > > > > > > > > > > On Tue, 2019-09-03 at 15:04 +0800, Tomasz Figa wrote:
> > > > > > > > > > > > On Tue, Sep 3, 2019 at 3:44 PM Jerry-ch Chen <Jerry-ch.Chen@mediatek.com> wrote:
> > > > > > > > > > > > >
> > > > > > > > > > > > > On Tue, 2019-09-03 at 13:19 +0800, Tomasz Figa wrote:
> > > > > > > > > > > > > > On Mon, Sep 2, 2019 at 8:47 PM Jerry-ch Chen <Jerry-ch.Chen@mediatek.com> wrote:
> > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > Hi Tomasz,
> > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > On Fri, 2019-08-30 at 16:33 +0800, Tomasz Figa wrote:
> > > > > > > > > > > > > > > > On Wed, Aug 28, 2019 at 11:00 AM Jerry-ch Chen
> > > > > > > > > > > > > > > > <Jerry-ch.Chen@mediatek.com> wrote:
> > > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > > > Hi Tomasz,
> > > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > > > On Mon, 2019-08-26 at 14:36 +0800, Tomasz Figa wrote:
> > > > > > > > > > > > > > > > > > Hi Jerry,
> > > > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > > > > On Sun, Aug 25, 2019 at 6:18 PM Jerry-ch Chen
> > > > > > > > > > > > > > > > > > <Jerry-ch.Chen@mediatek.com> wrote:
> > > > > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > > > > > Hi Tomasz,
> > > > > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > > > > > On Fri, 2019-08-02 at 16:28 +0800, Tomasz Figa wrote:
> > > > > > > > > > > > > > > > > > > > Hi Jerry,
> > > > > > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > > > > > > On Tue, Jul 09, 2019 at 04:41:12PM +0800, Jerry-ch Chen wrote:
> [snip]
> > > > > static void mtk_fd_vb2_stop_streaming(struct vb2_queue *vq)
> > > > > {
> > > > >         struct mtk_fd_ctx *ctx = vb2_get_drv_priv(vq);
> > > > >         struct mtk_fd_dev *fd = ctx->fd_dev;
> > > > >         struct vb2_v4l2_buffer *vb;
> > > > >         struct v4l2_m2m_ctx *m2m_ctx = ctx->fh.m2m_ctx;
> > > > >         struct v4l2_m2m_queue_ctx *queue_ctx;
> > > > >         u32 ret;
> > > > >
> > > > >         if (!fd->fd_irq_done.done)
> > > >
> > > > We shouldn't access internal fields of completion.
> > > >
> > > > >                 ret = wait_for_completion_timeout(&fd->fd_irq_done,
> > > > >                                                   msecs_to_jiffies(
> > > > >                                                         MTK_FD_HW_TIMEOUT));
> > > > >         queue_ctx = V4L2_TYPE_IS_OUTPUT(vq->type) ?
> > > > >                                         &m2m_ctx->out_q_ctx :
> > > > >                                         &m2m_ctx->cap_q_ctx;
> > > > >         while ((vb = v4l2_m2m_buf_remove(queue_ctx)))
> > > > >                 v4l2_m2m_buf_done(vb, VB2_BUF_STATE_ERROR);
> > > > >
> > > > >         if (vq->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
> > > > >                 mtk_fd_hw_disconnect(fd);
> > > > > }
> > > > >
> > > > > I've also tried to wait completion unconditionally for both queues and
> > > > > the second time will wait until timeout, as a result, it takes longer to
> > > > > swap the camera every time and close the camera app.
> > > >
> > > > I think it should work better if we call complete_all() instead of complete().
> > > >
> > > Thanks,
> > >
> > > I use complete_all(), and it works fine now.
> > >
> > > static void mtk_fd_vb2_stop_streaming(struct vb2_queue *vq)
> > > {
> > >         struct mtk_fd_ctx *ctx = vb2_get_drv_priv(vq);
> > >         struct mtk_fd_dev *fd = ctx->fd_dev;
> > >         struct vb2_v4l2_buffer *vb;
> > >         struct v4l2_m2m_ctx *m2m_ctx = ctx->fh.m2m_ctx;
> > >         struct v4l2_m2m_queue_ctx *queue_ctx;
> > >
> > >         wait_for_completion_timeout(&fd->fd_irq_done,
> > >                                           msecs_to_jiffies(MTK_FD_HW_TIMEOUT));
> >
> > Shouldn't we still send some command to the hardware to stop? Like a
> > reset. Otherwise we don't know if it isn't still accessing the memory.
> >
> I thought no more jobs will be enqueued here when stop_streaming so we
> don't need it.

That's true for the case when the wait completed successfully, but we
also need to ensure the hardware is stopped even if a timeout happens.

> We still could send an ipi command to reset the HW, and wait for it's
> callback or we could set the register MTK_FD_REG_OFFSET_HW_ENABLE to
> zero to disable the HW.

Since it's for handling a timeout, a reset should be more likely to
bring the hardware back to a reasonable state.

>
> Best regards,
> Jerry
>
> > >         queue_ctx = V4L2_TYPE_IS_OUTPUT(vq->type) ?
> > >                                         &m2m_ctx->out_q_ctx :
> > >                                         &m2m_ctx->cap_q_ctx;
> > >         while ((vb = v4l2_m2m_buf_remove(queue_ctx)))
> > >                 v4l2_m2m_buf_done(vb, VB2_BUF_STATE_ERROR);
> > >
> > >         if (vq->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
> > >                 mtk_fd_hw_disconnect(fd);
> > > }
> > >
> > > Best regards,
> > > Jerry
> > >
> > > > Best regards,
> > > > Tomasz
> > >
> > >
>
>

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