2023-10-26 12:28:55

by Ricardo Ribalda

Subject: [PATCH] usb: dwc3: set the dma max_seg_size

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]

Reported-by: Zubin Mithra <[email protected]>
Signed-off-by: Ricardo Ribalda <[email protected]>
---
Found while running
yavta -f YUYV -s 1280x720 -c /dev/video0

with:

CONFIG_DMA_API_DEBUG=y
---
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 <[email protected]>

2023-10-27 10:51:54

by Greg Kroah-Hartman

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

On Thu, Oct 26, 2023 at 12:28:36PM +0000, 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]
>
> Reported-by: Zubin Mithra <[email protected]>
> Signed-off-by: Ricardo Ribalda <[email protected]>
> ---
> Found while running
> yavta -f YUYV -s 1280x720 -c /dev/video0
>
> with:
>
> CONFIG_DMA_API_DEBUG=y
> ---
> drivers/usb/dwc3/core.c | 2 ++
> 1 file changed, 2 insertions(+)

What commit id does this fix?

thanks,

greg k-h

2023-10-27 11:26:26

by Greg Kroah-Hartman

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

On Fri, Oct 27, 2023 at 12:56:49PM +0200, Ricardo Ribalda wrote:
> Hi Greg
>
> On Fri, 27 Oct 2023 at 12:51, Greg Kroah-Hartman
> <[email protected]> wrote:
> > What commit id does this fix?
> Fixes: 72246da40f37 ("usb: Introduce DesignWare USB3 DRD Driver")
>
> Shall I send v2? or you can pick the tag?

Please send a v2 as you now obviously will also have to add a proper
"cc: stable..." tag as well, right?

thanks,

greg k-h