Fix commit 7b81cb6b ("usb: add a HCD_DMA flag instead of
guestimating DMA capabilities") where local memory USB drivers
erroneously allocate DMA memory instead of pool memory, causing

	OHCI Unrecoverable Error, disabled
	HC died; cleaning up

The order between hcd_uses_dma() and hcd->localmem_pool is now
arranged as in hcd_buffer_alloc() and hcd_buffer_free(), with the
test for hcd->localmem_pool placed first.

As an alternative, one might consider adjusting hcd_uses_dma() with

 static inline bool hcd_uses_dma(struct usb_hcd *hcd)
 {
-	return IS_ENABLED(CONFIG_HAS_DMA) && (hcd->driver->flags & HCD_DMA);
+	return IS_ENABLED(CONFIG_HAS_DMA) &&
+		(hcd->driver->flags & HCD_DMA) &&
+		(hcd->localmem_pool == NULL);
 }

One can also consider unsetting HCD_DMA for local memory pool drivers.

Fixes: 7b81cb6b

 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Fredrik Noring <noring@nocrew.org>
Link: https://lore.kernel.org/r/20191210172905.GA52526@sx9


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>