Messages in this thread | | | Date | Thu, 29 Jun 2023 12:40:03 +0100 | Subject | Re: [PATCH] usb: xhci-mtk: set the dma max_seg_size | From | Robin Murphy <> |
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On 2023-06-29 09:40, Greg Kroah-Hartman wrote: > On Thu, Jun 29, 2023 at 09:13:23AM +0200, Ricardo Ribalda wrote: >> Hi Zubin >> >> On Wed, 28 Jun 2023 at 23:57, Zubin Mithra <zsm@chromium.org> wrote: >>> >>> On Wed, Jun 28, 2023 at 11:04:20PM +0200, Ricardo Ribalda wrote: >>>> On Wed, 28 Jun 2023 at 23:00, Ricardo Ribalda <ribalda@chromium.org> wrote: >>>>> >>>>> Allow devices to have dma operations beyond 64K, and avoid warnings such >>>>> as: >>>>> >>>>> DMA-API: xhci-mtk 11200000.usb: mapping sg segment longer than device claims to support [len=98304] [max=65536] >>>>> >>>>> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> >>>> Reported-by: Zubin Mithra <zsm@chromium.org> >>> >>> Should this be cc'd to stable@ as well? >> >> Not sure, in most of the cases this is "just" a warning fix. Let the >> maintainer decide: > > Warnings can cause reboots as the majority of the linux systems in the > world run panic-on-warn, so yes, it should be backported.
Although in this particular case, running DMA_API_DEBUG=y on production systems is a pretty inadvisable thing to do anyway ;)
However I'm glad I looked, since I think this also points to a bug in dma_alloc_noncontiguous() - it's one thing to blame a driver for trying to map a malformed scatterlist of its own, but if the DMA API is generating one internally without respecting the device's (claimed) parameters, then that's on us. I'll have a look into it...
Thanks, Robin.
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