On Wed, Jul 24, 2019 at 05:43:47PM +0200, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
>
> The patch below does not apply to the 5.2-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@xxxxxxxxxxxxxxx>.
>
> thanks,
>
> greg k-h
>
> ------------------ original commit in Linus's tree ------------------
>
> >From 13b82b746310b51b064bc855993a1c84bf862726 Mon Sep 17 00:00:00 2001
> From: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
> Date: Wed, 22 May 2019 14:34:00 +0300
> Subject: [PATCH] xhci: Fix immediate data transfer if buffer is already DMA
> mapped
>
> xhci immediate data transfer (IDT) support in 5.2-rc1 caused regression
> on various Samsung Exynos boards with ASIX USB 2.0 ethernet dongle.
>
> If the transfer buffer in the URB is already DMA mapped then IDT should
> not be used. urb->transfer_dma will already contain a valid dma address,
> and there is no guarantee the data in urb->transfer_buffer is valid.
>
> The IDT support patch used urb->transfer_dma as a temporary storage,
> copying data from urb->transfer_buffer into it.
>
> Issue was solved by preventing IDT if transfer buffer is already dma
> mapped, and by not using urb->transfer_dma as temporary storage.
>
> Fixes: 33e39350ebd2 ("usb: xhci: add Immediate Data Transfer support")
> Reported-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> CC: Nicolas Saenz Julienne <nsaenzjulienne@xxxxxxx>
> Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Oh nevermind, this should be a 5.2-only thing.
it shouldn't affect anyone, sorry for the noise.
greg k-h
