Subject: Re: [RFC PATCH V2 4/4] platform: mtk-isp: Add Mediatek FD driver

From: Jerry-ch Chen <[email-masked]>
Date: Thu, 5 Sep 2019 16:16:58 +0800

Hi Tomasz,

On Thu, 2019-09-05 at 15:13 +0800, Tomasz Figa wrote:
> On Thu, Sep 5, 2019 at 4:02 PM Jerry-ch Chen <[email-masked]> wrote:
> >
> > Hi Tomasz,
> >
> > On Wed, 2019-09-04 at 21:19 +0800, Jerry-ch Chen wrote:
> > > On Wed, 2019-09-04 at 21:12 +0800, Tomasz Figa wrote:
> > > > On Wed, Sep 4, 2019 at 6:26 PM Jerry-ch Chen <[email-masked]> 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 <[email-masked]> 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 <[email-masked]> 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 <[email-masked]> 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
> > > > > > > > > > > > <[email-masked]> 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 <[email-masked]> 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 <[email-masked]> 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 <[email-masked]> 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
> > > > > > > > > > > > > > > > > > > > <[email-masked]> 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
> > > > > > > > > > > > > > > > > > > > > > <[email-masked]> 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.
> > > >
> > >
> > > Ok, I will send the ipi command to reset the HW.
> > >
> > > Thanks and best regards,
> > > Jerry
> > I've tested and will refine as following:
> >
> > 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;
> >
> >         ret = wait_for_completion_timeout(&fd->fd_irq_done,
> >                                           msecs_to_jiffies(MTK_FD_HW_TIMEOUT));
> >         /* Disable FD HW */
> >         if(!ret) {
> >                 struct ipi_message fd_ipi_msg;
> >
> >                 fd_ipi_msg.cmd_id = MTK_FD_IPI_CMD_RESET;
> >                 ret = scp_ipi_send(fd->scp_pdev, SCP_IPI_FD_CMD, &fd_ipi_msg,
> >                                    sizeof(fd_ipi_msg), MTK_FD_IPI_SEND_TIMEOUT);
> >                 if (ret)
> >                         dev_err(fd->dev, "FD Reset HW error\n");
> >         }
> 
> Would you also put the same code in suspend handler? If so, perhaps
> it's better to keep this in a helper function (mtk_fd_job_abort()) as
> we had before?
> 

Ok, done, It will reset the HW and return ETIMEOUT if the last job is
timeout, the return value will be used in suspend for further action.

static int mtk_fd_job_abort(struct mtk_fd_dev *fd)
{
	u32 ret;

	ret = wait_for_completion_timeout(&fd->fd_irq_done,
					  msecs_to_jiffies(MTK_FD_HW_TIMEOUT));
	/* Reset FD HW */
	if (!ret) {
		struct ipi_message fd_ipi_msg;

		fd_ipi_msg.cmd_id = MTK_FD_IPI_CMD_RESET;
		if (scp_ipi_send(fd->scp_pdev, SCP_IPI_FD_CMD, &fd_ipi_msg,
				 sizeof(fd_ipi_msg), MTK_FD_IPI_SEND_TIMEOUT))
			dev_err(fd->dev, "FD Reset HW error\n");
		return -ETIMEDOUT;
	}
	return 0;
}

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;

	mtk_fd_job_abort(fd);
	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);
}

static int mtk_fd_suspend(struct device *dev)
{
	struct mtk_fd_dev *fd = dev_get_drvdata(dev);

	if (pm_runtime_suspended(dev))
		return 0;

	if (fd->fd_stream_count)
		if (mtk_fd_job_abort(fd))
			mtk_fd_hw_job_finish(fd, VB2_BUF_STATE_ERROR);

	/* suspend FD HW */
	writel(0x0, fd->fd_base + MTK_FD_REG_OFFSET_INT_EN);
	writel(0x0, fd->fd_base + MTK_FD_REG_OFFSET_HW_ENABLE);
	clk_disable_unprepare(fd->fd_clk);
	dev_dbg(dev, "%s:disable clock\n", __func__);

	return 0;
}

> >         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);
> > }
> >
> > If there is no other concern, may I send the RFC v3 patch for review?
> 
> Thanks, technically it looks good now. Just one comment about avoiding
> code duplication above.
> 

Thanks, 

I will send the v3 if the above fix-up is accepted,

Best regards,
Jerry

> Best regards,
> Tomasz

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