Re: [PATCH v2] usb: dwc3: set the dma max_seg_size

From: Thinh Nguyen
Date: Tue Oct 31 2023 - 19:22:50 EST


On Fri, Oct 27, 2023, Ricardo Ribalda wrote:
> Allow devices to have dma operations beyond 4K, and avoid warnings such
> as:
>
> DMA-API: dwc3 a600000.usb: mapping sg segment longer than device claims to support [len=86016] [max=65536]
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 72246da40f37 ("usb: Introduce DesignWare USB3 DRD Driver")
> Reported-by: Zubin Mithra <zsm@xxxxxxxxxxxx>
> Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
> ---
> Found while running
> yavta -f YUYV -s 1280x720 -c /dev/video0
>
> with:
>
> CONFIG_DMA_API_DEBUG=y
> ---
> Changes in v2:
> - Add stable tag
> - Link to v1: https://urldefense.com/v3/__https://lore.kernel.org/r/20231026-dwc3-v1-1-643c74771599@chromium.org__;!!A4F2R9G_pg!b22b7Wx1QOpnFtMi7rJ0TS-rhOnMmy_sOCX3kdfln7ezNjslyMhBwHvWaXbK8D5BkKPjjn3HdID-7Ls5R3eR_4o$
> ---
> drivers/usb/dwc3/core.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 343d2570189f..65f73dd8ef47 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -1918,6 +1918,8 @@ static int dwc3_probe(struct platform_device *pdev)
>
> pm_runtime_put(dev);
>
> + dma_set_max_seg_size(dev, UINT_MAX);
> +
> return 0;
>
> err_exit_debugfs:
>
> ---
> base-commit: 611da07b89fdd53f140d7b33013f255bf0ed8f34
> change-id: 20231026-dwc3-fac74fcb3b2a
>
> Best regards,
> --
> Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
>

Probably better to have the Closes: tag with the link to the reported
issue. Regardless,

Acked-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>

Thanks,
Thinh