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authorClemens Ladisch <clemens@ladisch.de>2011-12-03 23:41:31 +0100
committerGreg Kroah-Hartman <gregkh@suse.de>2011-12-09 16:18:19 -0800
commitbc677d5b64644c399cd3db6a905453e611f402ab (patch)
treed973a02c33f0e0d407e9ec7c6054220e15d5c72f /drivers/usb/host/ehci-q.c
parent8ad028bd973ec1ead4982e21ab0400c956aff4b5 (diff)
downloadlinux-stericsson-bc677d5b64644c399cd3db6a905453e611f402ab.tar.gz
usb: fix number of mapped SG DMA entries
Add a new field num_mapped_sgs to struct urb so that we have a place to store the number of mapped entries and can also retain the original value of entries in num_sgs. Previously, usb_hcd_map_urb_for_dma() would overwrite this with the number of mapped entries, which would break dma_unmap_sg() because it requires the original number of entries. This fixes warnings like the following when using USB storage devices: ------------[ cut here ]------------ WARNING: at lib/dma-debug.c:902 check_unmap+0x4e4/0x695() ehci_hcd 0000:00:12.2: DMA-API: device driver frees DMA sg list with different entry count [map count=4] [unmap count=1] Modules linked in: ohci_hcd ehci_hcd Pid: 0, comm: kworker/0:1 Not tainted 3.2.0-rc2+ #319 Call Trace: <IRQ> [<ffffffff81036d3b>] warn_slowpath_common+0x80/0x98 [<ffffffff81036de7>] warn_slowpath_fmt+0x41/0x43 [<ffffffff811fa5ae>] check_unmap+0x4e4/0x695 [<ffffffff8105e92c>] ? trace_hardirqs_off+0xd/0xf [<ffffffff8147208b>] ? _raw_spin_unlock_irqrestore+0x33/0x50 [<ffffffff811fa84a>] debug_dma_unmap_sg+0xeb/0x117 [<ffffffff8137b02f>] usb_hcd_unmap_urb_for_dma+0x71/0x188 [<ffffffff8137b166>] unmap_urb_for_dma+0x20/0x22 [<ffffffff8137b1c5>] usb_hcd_giveback_urb+0x5d/0xc0 [<ffffffffa0000d02>] ehci_urb_done+0xf7/0x10c [ehci_hcd] [<ffffffffa0001140>] qh_completions+0x429/0x4bd [ehci_hcd] [<ffffffffa000340a>] ehci_work+0x95/0x9c0 [ehci_hcd] ... ---[ end trace f29ac88a5a48c580 ]--- Mapped at: [<ffffffff811faac4>] debug_dma_map_sg+0x45/0x139 [<ffffffff8137bc0b>] usb_hcd_map_urb_for_dma+0x22e/0x478 [<ffffffff8137c494>] usb_hcd_submit_urb+0x63f/0x6fa [<ffffffff8137d01c>] usb_submit_urb+0x2c7/0x2de [<ffffffff8137dcd4>] usb_sg_wait+0x55/0x161 Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/host/ehci-q.c')
-rw-r--r--drivers/usb/host/ehci-q.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c
index f136f7f1c4f4..36ca5077cdf7 100644
--- a/drivers/usb/host/ehci-q.c
+++ b/drivers/usb/host/ehci-q.c
@@ -658,7 +658,7 @@ qh_urb_transaction (
/*
* data transfer stage: buffer setup
*/
- i = urb->num_sgs;
+ i = urb->num_mapped_sgs;
if (len > 0 && i > 0) {
sg = urb->sg;
buf = sg_dma_address(sg);