On Wed, 26 Aug 2020 09:36:39 +0300
Alexandru Ardelean <ardeleanalex@xxxxxxxxx> wrote:
> On Wed, Aug 26, 2020 at 8:22 AM Lars-Peter Clausen <lars@xxxxxxxxxx> wrote:
> >
> > From: Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx>
> >
> > A transfer may fall shorter than the bytes in the block.
> > This information is available in the residue from the DMA engine, so we can
> > compute actual `bytes_used` with that by subtracting the residue.
> >
>
> This was in my pipeline as well [obviously].
> Thanks :)
>
> > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx>
> > Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
"smells" like a fix. Is it? Or are we looking at something that
only matters for some future hardware, or an optmization?
If it's a fix, where is the fixes tag?
Thanks,
Jonathan
> > ---
> > drivers/iio/buffer/industrialio-buffer-dmaengine.c | 6 ++++--
> > 1 file changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/iio/buffer/industrialio-buffer-dmaengine.c b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
> > index 6dedf12b69a4..5789bda0745b 100644
> > --- a/drivers/iio/buffer/industrialio-buffer-dmaengine.c
> > +++ b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
> > @@ -45,7 +45,8 @@ static struct dmaengine_buffer *iio_buffer_to_dmaengine_buffer(
> > return container_of(buffer, struct dmaengine_buffer, queue.buffer);
> > }
> >
> > -static void iio_dmaengine_buffer_block_done(void *data)
> > +static void iio_dmaengine_buffer_block_done(void *data,
> > + const struct dmaengine_result *result)
> > {
> > struct iio_dma_buffer_block *block = data;
> > unsigned long flags;
> > @@ -53,6 +54,7 @@ static void iio_dmaengine_buffer_block_done(void *data)
> > spin_lock_irqsave(&block->queue->list_lock, flags);
> > list_del(&block->head);
> > spin_unlock_irqrestore(&block->queue->list_lock, flags);
> > + block->bytes_used -= result->residue;
> > iio_dma_buffer_block_done(block);
> > }
> >
> > @@ -74,7 +76,7 @@ static int iio_dmaengine_buffer_submit_block(struct iio_dma_buffer_queue *queue,
> > if (!desc)
> > return -ENOMEM;
> >
> > - desc->callback = iio_dmaengine_buffer_block_done;
> > + desc->callback_result = iio_dmaengine_buffer_block_done;
> > desc->callback_param = block;
> >
> > cookie = dmaengine_submit(desc);
> > --
> > 2.20.1
> >
