diff options
| author | Alan Stern <stern@rowland.harvard.edu> | 2010-04-02 13:27:28 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-05-20 13:21:37 -0700 |
| commit | ff9c895f07d36193c75533bda8193bde8ca99d02 (patch) | |
| tree | 386ca8e37734c4810e59a55eaba92e4e88275d14 /drivers/usb/host | |
| parent | 0ff8d1b3c858ea7c8daa54f7577971a76d04d283 (diff) | |
USB: fix usbmon and DMA mapping for scatter-gather URBs
This patch (as1368) fixes a rather obscure bug in usbmon: When tracing
URBs sent by the scatter-gather library, it accesses the data buffers
while they are still mapped for DMA.
The solution is to move the mapping and unmapping out of the s-g
library and into the usual place in hcd.c. This requires the addition
of new URB flag bits to describe the kind of mapping needed, since we
have to call dma_map_sg() if the HCD supports native scatter-gather
operation and dma_map_page() if it doesn't. The nice thing about
having the new flags is that they simplify the testing for unmapping.
The patch removes the only caller of usb_buffer_[un]map_sg(), so those
functions are #if'ed out. A later patch will remove them entirely.
As a result of this change, urb->sg will be set in situations where
it wasn't set previously. Hence the xhci and whci drivers are
adjusted to test urb->num_sgs instead, which retains its original
meaning and is nonzero only when the HCD has to handle a scatterlist.
Finally, even when a submission error occurs we don't want to hand
URBs to usbmon before they are unmapped. The submission path is
rearranged so that map_urb_for_dma() is called only for non-root-hub
URBs and unmap_urb_for_dma() is called immediately after a submission
error. This simplifies the error handling.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/host')
| -rw-r--r-- | drivers/usb/host/whci/qset.c | 2 | ||||
| -rw-r--r-- | drivers/usb/host/xhci-ring.c | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/drivers/usb/host/whci/qset.c b/drivers/usb/host/whci/qset.c index 141d049beb3e..b388dd1fb4c4 100644 --- a/drivers/usb/host/whci/qset.c +++ b/drivers/usb/host/whci/qset.c @@ -646,7 +646,7 @@ int qset_add_urb(struct whc *whc, struct whc_qset *qset, struct urb *urb, wurb->urb = urb; INIT_WORK(&wurb->dequeue_work, urb_dequeue_work); - if (urb->sg) { + if (urb->num_sgs) { ret = qset_add_urb_sg(whc, qset, urb, mem_flags); if (ret == -EINVAL) { qset_free_stds(qset, urb); diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 407d33fb5e84..c1359ed310b5 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -1962,7 +1962,7 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags, int running_total, trb_buff_len, ret; u64 addr; - if (urb->sg) + if (urb->num_sgs) return queue_bulk_sg_tx(xhci, mem_flags, urb, slot_id, ep_index); ep_ring = xhci->devs[slot_id]->eps[ep_index].ring; |