diff options
| author | Clemens Ladisch <clemens@ladisch.de> | 2011-12-03 23:41:31 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2012-01-12 11:35:25 -0800 |
| commit | 766b8a7f7ee006dfd73dbc676addd80f7dbe86ef (patch) | |
| tree | 818c4c1709838ac321940e68624ec6d0228b9db1 /include/linux | |
| parent | 0d5b25f934978301b2a1385c72f3b6abe04db484 (diff) | |
usb: fix number of mapped SG DMA entries
commit bc677d5b64644c399cd3db6a905453e611f402ab upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/usb.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/usb.h b/include/linux/usb.h index 73c7df489607..b08e04cf202b 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -1202,6 +1202,7 @@ struct urb { void *transfer_buffer; /* (in) associated data buffer */ dma_addr_t transfer_dma; /* (in) dma addr for transfer_buffer */ struct scatterlist *sg; /* (in) scatter gather buffer list */ + int num_mapped_sgs; /* (internal) mapped sg entries */ int num_sgs; /* (in) number of entries in the sg list */ u32 transfer_buffer_length; /* (in) data buffer length */ u32 actual_length; /* (return) actual transfer length */ |