From: Dan Williams <dan.j.williams@xxxxxxxxx>
Save someone else the debug cycles of figuring out why a driver's
transfer request is failing or causing undefined system behavior.
Buffers submitted for dma must come from GFP allocated / DMA-able
memory.
Return -EAGAIN matching the return value for dma_mapping_error() cases.
Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Cc: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx>
Cc: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
---
drivers/usb/core/hcd.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 9c4e292..adddc66 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -1502,6 +1502,9 @@ int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
ret = -EAGAIN;
else
urb->transfer_flags |= URB_DMA_MAP_PAGE;
+ } else if (is_vmalloc_addr(urb->transfer_buffer)) {
+ WARN_ONCE(1, "transfer buffer not dma capable\n");
+ ret = -EAGAIN;
} else {
urb->transfer_dma = dma_map_single(
hcd->self.controller,
--
1.8.3.2
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