[PATCH 1/1] Fix 'bad dma' problem on WDM device disconnect

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



In the WDM class driver a disconnect event leads to calls to
usb_free_coherent to put back two USB DMA buffers allocated earlier.
The call to usb_free_coherent uses a different size parameter 
(desc->wMaxCommand) than the corresponding call to usb_alloc_coherent
(desc->bMaxPacketSize0).

When a disconnect event occurs, this leads to 'bad dma' complaints 
from usb core because the USB DMA buffer is being pushed back to the
'buffer-2048' pool from which it has not been allocated. 

This patch against the most recent linux-2.6 kernel ensures that the 
parameters used by usb_alloc_coherent & usb_free_coherent calls in 
cdc-wdm.c match.

Signed-off-by: Robert Lukassen <robert.lukassen@xxxxxxxxxx>
---
 drivers/usb/class/cdc-wdm.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index 47085e5..a97c018 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -281,7 +281,7 @@ static void cleanup(struct wdm_device *desc)
                          desc->sbuf,
                          desc->validity->transfer_dma);
        usb_free_coherent(interface_to_usbdev(desc->intf),
-                         desc->wMaxCommand,
+                         desc->bMaxPacketSize0,
                          desc->inbuf,
                          desc->response->transfer_dma);
        kfree(desc->orq);
-- 
1.7.0.4
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux Media]     [Linux Input]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Old Linux USB Devel Archive]

  Powered by Linux