On Wed, Jul 26, 2023 at 05:28:37PM +0300, Laurent Pinchart wrote:
> Hi Wang,
>
> Thank you for the patch.
>
> On Wed, Jul 26, 2023 at 07:51:58PM +0800, Wang Ming wrote:
> > It is possible that dma_request_chan will return EPROBE_DEFER,
> > which means that dma->xdev->dev is not ready yet. In this case,
> > dev_err(dma->xdev->dev), there will be no output. This patch
> > fixes the bug.
>
> It's not a bug. The existing code works as expected. dev_err_probe() is
> nicer though, as it records the reason for the probe deferral. Here's a
> proposal for a better commit message:
>
> It is possible that dma_request_chan() returns EPROBE_DEFER, in which
> case the driver defers probing without printing any message. Use
> dev_err_probe() to record the probe deferral cause and ease debugging.
>
> If you're fine with this, there's no need to resubmit, I'll update the
> commit message locally and merge the patch.
>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
>
> > Signed-off-by: Wang Ming <machel@xxxxxxxx>
> > ---
> > drivers/media/platform/xilinx/xilinx-dma.c | 5 ++---
> > 1 file changed, 2 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/media/platform/xilinx/xilinx-dma.c b/drivers/media/platform/xilinx/xilinx-dma.c
> > index 80d6f5b072ea..16ad39bef6c6 100644
> > --- a/drivers/media/platform/xilinx/xilinx-dma.c
> > +++ b/drivers/media/platform/xilinx/xilinx-dma.c
> > @@ -708,9 +708,8 @@ int xvip_dma_init(struct xvip_composite_device *xdev, struct xvip_dma *dma,
> > snprintf(name, sizeof(name), "port%u", port);
> > dma->dma = dma_request_chan(dma->xdev->dev, name);
> > if (IS_ERR(dma->dma)) {
> > - ret = PTR_ERR(dma->dma);
> > - if (ret != -EPROBE_DEFER)
> > - dev_err(dma->xdev->dev, "no VDMA channel found\n");
> > + ret = dev_err_probe(dma->xdev->dev, PTR_ERR(dma->dma),
> > + "no VDMA channel found\n");
I forgot to mention that the message should be aligned:
ret = dev_err_probe(dma->xdev->dev, PTR_ERR(dma->dma),
"no VDMA channel found\n");
I can fix this locally too.
> > goto error;
> > }
> >
--
Regards,
Laurent Pinchart
