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 15:02:20 +0800

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");
	}
	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 and best regards,
Jerry
> > >
> > > 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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