On Sat, 4 Jun 2022, Vincent MAILHOL wrote: > > For me, the natural fix would be: > > > > diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c > > index 33d62d7e3929..1460fdac0b18 100644 > > --- a/drivers/usb/core/urb.c > > +++ b/drivers/usb/core/urb.c > > @@ -22,6 +22,9 @@ static void urb_destroy(struct kref *kref) > > > > if (urb->transfer_flags & URB_FREE_BUFFER) > > kfree(urb->transfer_buffer); > > + else if (urb->transfer_flags & URB_FREE_COHERENT) > > + usb_free_coherent(urb->dev, urb->transfer_buffer_length, > > + urb->transfer_buffer, urb->transfer_dma); > > > > kfree(urb); > > } > > diff --git a/include/linux/usb.h b/include/linux/usb.h > > index 200b7b79acb5..dfc348d56fed 100644 > > --- a/include/linux/usb.h > > +++ b/include/linux/usb.h > > @@ -1328,6 +1328,7 @@ extern int usb_disabled(void); > > #define URB_NO_INTERRUPT 0x0080 /* HINT: no non-error interrupt > > * needed */ > > #define URB_FREE_BUFFER 0x0100 /* Free transfer buffer with the URB */ > > +#define URB_FREE_COHERENT 0x0200 /* Free DMA memory of transfer buffer */ > > #define URB_FREE_COHERENT 0x0400 /* Free DMA memory of transfer buffer */ > > Obviously, the value 0x0200 is already taken by URB_DIR_IN just below. > So 0x0400 seems more adequate. > Sorry for the noise. Now that you've pointed this out, I agree this appears to be the more natural way to handle things. I will take a point of making a rewrite here. Additionally, I'll do my best to bring all the other USB CAN drivers in line with this. My only concern in doing that is that I have gs_usb devices to confirm the fix with but not devices for the other drivers. > > Maybe I missed something obvious, but if so, I would like to > > understand what is wrong in above approach. I don't think anything is wrong with the above approach. I just happened to see an issue in the gs_usb driver that was already fixed in the other USB CAN drivers, and adapted the fix used in the other drivers to the gs_usb one. Doing so got your attention and you pointed out a more general fix, so I agree with going this route. I'll post a new patch this week. Best, Rhett
