Re: [PATCH] staging: emxx_udc: Fix passing of NULL to dma_alloc_coherent()

[Alex Dewar]

On Mon, Aug 24, 2020 at 04:19:17PM +0100, Alex Dewar wrote:
> In nbu2ss_eq_queue() memory is allocated with dma_alloc_coherent(),
> though, strangely, NULL is passed as the struct device* argument. Pass
> the UDC's device instead.
> 
> Build-tested on x86 only.
> 
> Fixes: 33aa8d45a4fe ("staging: emxx_udc: Add Emma Mobile USB Gadget driver")
> Signed-off-by: Alex Dewar <alex.dewar90@xxxxxxxxx>
> ---
> 
> So I *think* this is the right fix, but I don't have the hardware so
> I've only been able to build-test it. My worry is that I could be
> passing in the wrong struct device* here, which would squelch the
> warning without fixing the breakage.
> 
> Can someone cleverer than me tell me if this makes sense?
> 
> - Alex

PS -- I meant to put an RFC in the subject line and an extra tag:
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

> ---
>  drivers/staging/emxx_udc/emxx_udc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/emxx_udc/emxx_udc.c b/drivers/staging/emxx_udc/emxx_udc.c
> index 03929b9d3a8b..09e91449c08c 100644
> --- a/drivers/staging/emxx_udc/emxx_udc.c
> +++ b/drivers/staging/emxx_udc/emxx_udc.c
> @@ -2593,7 +2593,7 @@ static int nbu2ss_ep_queue(struct usb_ep *_ep,
>  
>  	if (req->unaligned) {
>  		if (!ep->virt_buf)
> -			ep->virt_buf = dma_alloc_coherent(NULL, PAGE_SIZE,
> +			ep->virt_buf = dma_alloc_coherent(udc->dev, PAGE_SIZE,
>  							  &ep->phys_buf,
>  							  GFP_ATOMIC | GFP_DMA);
>  		if (ep->epnum > 0)  {
> -- 
> 2.28.0
>