[ 27/80] rtlwifi: fix incorrect use of usb_alloc_coherent with usb_control_msg

Greg Kroah-Hartman
2013-01-09T20:38:43Z

From: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>

commit 4c3de5920c486b8eefa6187ee6a181864c161100 upstream.

Incorrect use of usb_alloc_coherent memory as input buffer to usb_control_msg
can cause problems in arch DMA code, for example kernel BUG at
'arch/arm/include/asm/dma-mapping.h:321' on ARM (linux-3.4).

Change _usb_writeN_sync use kmalloc'd buffer instead.

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/net/wireless/rtlwifi/usb.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

--- a/drivers/net/wireless/rtlwifi/usb.c
+++ b/drivers/net/wireless/rtlwifi/usb.c
@@ -210,17 +210,16 @@ static void _usb_writeN_sync(struct rtl_
u16 index = REALTEK_USB_VENQT_CMD_IDX;
int pipe = usb_sndctrlpipe(udev, 0); /* write_out */
u8 *buffer;
- dma_addr_t dma_addr;

- wvalue = (u16)(addr&0x0000ffff);
- buffer = usb_alloc_coherent(udev, (size_t)len, GFP_ATOMIC, &dma_addr);
+ wvalue = (u16)(addr & 0x0000ffff);
+ buffer = kmalloc(len, GFP_ATOMIC);
if (!buffer)
return;
memcpy(buffer, data, len);
usb_control_msg(udev, pipe, request, reqtype, wvalue,
index, buffer, len, 50);

- usb_free_coherent(udev, (size_t)len, buffer, dma_addr);
+ kfree(buffer);
}

static void _rtl_usb_io_handler_init(struct device *dev,