Re: [PATCH] USB: OHCI: ohci-sm501: complete URBs in BH context

[Christoph Hellwig]

On Mon, Aug 06, 2018 at 09:03:35AM -0700, Guenter Roeck wrote:
> Yes, I can confirm that the warning is gone in -next. Problem solved,
> except of course there are still the warnings about the missing
> coherent_dma_mask.
> 
> sm501-usb sm501-usb: SM501 OHCI
> sm501-usb sm501-usb: new USB bus registered, assigned bus number 1
> WARNING: CPU: 0 PID: 1 at ./include/linux/dma-mapping.h:516 ohci_init+0x194/0x2d8
> 
> Is that warning also not warranted for the given use case, or is
> the missing mask indeed necessary ? It is easy to add - see
> https://lore.kernel.org/patchwork/patch/971411/ - but I do wonder
> if that change is appropriate.

Yes, every driver using dma coherent functions should set a coherent
mask.