On 8/15/20 12:30 AM, Andy Shevchenko wrote:
> Refactor cio2_buffer_done() to get rid of infinite loop by replacing it by one
> with clear exit condition. This change also allows to check for an error ahead.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> ---
> drivers/media/pci/intel/ipu3/ipu3-cio2.c | 24 +++++++++++-------------
> 1 file changed, 11 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/media/pci/intel/ipu3/ipu3-cio2.c b/drivers/media/pci/intel/ipu3/ipu3-cio2.c
> index eee7f841050d..f4175dc1501a 100644
> --- a/drivers/media/pci/intel/ipu3/ipu3-cio2.c
> +++ b/drivers/media/pci/intel/ipu3/ipu3-cio2.c
> @@ -541,7 +541,7 @@ static void cio2_buffer_done(struct cio2_device *cio2, unsigned int dma_chan)
> {
> struct device *dev = &cio2->pci_dev->dev;
> struct cio2_queue *q = cio2->cur_queue;
> - int buffers_found = 0;
> + struct cio2_fbpt_entry *const entry;
No 'const' here.
> u64 ns = ktime_get_ns();
>
> if (dma_chan >= CIO2_QUEUES) {
> @@ -549,15 +549,18 @@ static void cio2_buffer_done(struct cio2_device *cio2, unsigned int dma_chan)
> return;
> }
>
> + entry = &q->fbpt[q->bufs_first * CIO2_MAX_LOPS];
> + if (entry->first_entry.ctrl & CIO2_FBPT_CTRL_VALID) {
> + dev_warn(&cio2->pci_dev->dev,
> + "no ready buffers found on DMA channel %u\n",
> + dma_chan);
> + return;
> + }
> +
> /* Find out which buffer(s) are ready */
> do {
> - struct cio2_fbpt_entry *const entry =
> - &q->fbpt[q->bufs_first * CIO2_MAX_LOPS];
> struct cio2_buffer *b;
>
> - if (entry->first_entry.ctrl & CIO2_FBPT_CTRL_VALID)
> - break;
> -
> b = q->bufs[q->bufs_first];
> if (b) {
> unsigned int bytes = entry[1].second_entry.num_of_bytes;
> @@ -579,13 +582,8 @@ static void cio2_buffer_done(struct cio2_device *cio2, unsigned int dma_chan)
> atomic_inc(&q->frame_sequence);
> cio2_fbpt_entry_init_dummy(cio2, entry);
> q->bufs_first = (q->bufs_first + 1) % CIO2_MAX_BUFFERS;
> - buffers_found++;
> - } while (1);
> -
> - if (buffers_found == 0)
> - dev_warn(&cio2->pci_dev->dev,
> - "no ready buffers found on DMA channel %u\n",
> - dma_chan);
> + entry = &q->fbpt[q->bufs_first * CIO2_MAX_LOPS];
> + } while (!(entry->first_entry.ctrl & CIO2_FBPT_CTRL_VALID));
> }
>
> static void cio2_queue_event_sof(struct cio2_device *cio2, struct cio2_queue *q)
>
--
Best regards,
Bingbu Cao
