Hi Wang,
Thank you for the patch.
On Wed, Jul 26, 2023 at 07:57:56PM +0800, Wang Ming wrote:
> It is possible that dma_request_chan will return EPROBE_DEFER,
> which means that disp->dev is not ready yet. In this case,
> dev_err(disp->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.
> Signed-off-by: Wang Ming <machel@xxxxxxxx>
> ---
> drivers/gpu/drm/xlnx/zynqmp_disp.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/xlnx/zynqmp_disp.c b/drivers/gpu/drm/xlnx/zynqmp_disp.c
> index 3b87eebddc97..676f09fe8594 100644
> --- a/drivers/gpu/drm/xlnx/zynqmp_disp.c
> +++ b/drivers/gpu/drm/xlnx/zynqmp_disp.c
> @@ -1094,8 +1094,8 @@ static int zynqmp_disp_layer_request_dma(struct zynqmp_disp *disp,
> "%s%u", dma_names[layer->id], i);
> dma->chan = dma_request_chan(disp->dev, dma_channel_name);
> if (IS_ERR(dma->chan)) {
> - dev_err(disp->dev, "failed to request dma channel\n");
> - ret = PTR_ERR(dma->chan);
> + ret = dev_err_probe(disp->dev, PTR_ERR(dma->chan),
> + "failed to request dma channel\n");
The alignment is wrong, this should be
ret = dev_err_probe(disp->dev, PTR_ERR(dma->chan),
"failed to request dma channel\n");
If you're fine with those changes, I can fix this locally, there's no
need to resubmit.
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> dma->chan = NULL;
> return ret;
> }
--
Regards,
Laurent Pinchart
