Hi Sakari, Yong,
> Subject: Re: [PATCH v7 3/3] intel-ipu3: cio2: Add new MIPI-CSI2 driver
>
> Hi Yong,
>
> Thanks for the update!
>
> I took a final glance, there are a few matters that still need to be
> addressed but
> then I think we're done. Please see below.
>
> Then we'll need an entry in the MAINTAINERS file in the kernel root directory.
> Could you add an entry for this driver in v8?
>
> On Thu, Nov 02, 2017 at 03:00:01PM -0500, Yong Zhi wrote:
> ...
> > +static int cio2_fbpt_rearrange(struct cio2_device *cio2, struct
> > +cio2_queue *q) {
> > + unsigned int i, j;
> > +
> > + for (i = 0, j = q->bufs_first; i < CIO2_MAX_BUFFERS;
> > + i++, j = (j + 1) % CIO2_MAX_BUFFERS)
> > + if (q->bufs[j])
> > + break;
> > +
> > + if (i == CIO2_MAX_BUFFERS)
> > + return 0;
>
> You always return 0. The return type could be void.
>
> You could also move this function just above the function using it (it's a
> single
> location).
>
> > +
> > + if (j) {
> > + arrange(q->fbpt, sizeof(struct cio2_fbpt_entry) *
> CIO2_MAX_LOPS,
> > + CIO2_MAX_BUFFERS, j);
> > + arrange(q->bufs, sizeof(struct cio2_buffer *),
> > + CIO2_MAX_BUFFERS, j);
> > + }
> > +
> > + /*
> > + * DMA clears the valid bit when accessing the buffer.
> > + * When stopping stream in suspend callback, some of the buffers
> > + * may be in invalid state. After resume, when DMA meets the invalid
> > + * buffer, it will halt and stop receiving new data.
> > + * To avoid DMA halting, set the valid bit for all buffers in FBPT.
> > + */
> > + for (i = 0; i < CIO2_MAX_BUFFERS; i++)
> > + cio2_fbpt_entry_enable(cio2, q->fbpt + i * CIO2_MAX_LOPS);
> > +
> > + return 0;
> > +}
>
> ...
>
> > +static int cio2_vb2_start_streaming(struct vb2_queue *vq, unsigned
> > +int count) {
> > + struct cio2_queue *q = vb2q_to_cio2_queue(vq);
> > + struct cio2_device *cio2 = vb2_get_drv_priv(vq);
> > + int r;
> > +
> > + cio2->cur_queue = q;
> > + atomic_set(&q->frame_sequence, 0);
> > +
> > + r = pm_runtime_get_sync(&cio2->pci_dev->dev);
> > + if (r < 0) {
> > + dev_info(&cio2->pci_dev->dev, "failed to set power %d\n", r);
> > + pm_runtime_put(&cio2->pci_dev->dev);
Shouldn't we use pm_runtime_put_noidle() here, so the usage_count gets
decremented?
> > + return r;
> > + }
> > +
> > + r = media_pipeline_start(&q->vdev.entity, &q->pipe);
> > + if (r)
> > + goto fail_pipeline;
> > +
> > + r = cio2_hw_init(cio2, q);
> > + if (r)
> > + goto fail_hw;
> > +
> > + /* Start streaming on sensor */
> > + r = v4l2_subdev_call(q->sensor, video, s_stream, 1);
> > + if (r)
> > + goto fail_csi2_subdev;
> > +
> > + cio2->streaming = true;
> > +
> > + return 0;
> > +
> > +fail_csi2_subdev:
> > + cio2_hw_exit(cio2, q);
> > +fail_hw:
> > + media_pipeline_stop(&q->vdev.entity);
> > +fail_pipeline:
> > + dev_dbg(&cio2->pci_dev->dev, "failed to start streaming (%d)\n", r);
> > + cio2_vb2_return_all_buffers(q);
>
> I believe there should be
>
> pm_runtime_put(&cio2->pci_dev->dev);
>
> here. You should also add a label and use goto from where you do
> pm_runtime_put() in error handling in this function in order to make this
> cleaner.
>
> > +
> > + return r;
> > +}
>
> --
> Kind regards,
>
> Sakari Ailus
> sakari.ai...@linux.intel.com
