rtlwifi: fix incorrect use of usb_alloc_coherent with usb_control_msg

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. Cc: [email protected] Signed-off-by: Jussi Kivilinna <[email protected]> Acked-by: Larry Finger <[email protected]> Signed-off-by: John W. Linville <[email protected]>
zehome · Jan 2, 2013 · 4c3de59 · 4c3de59
1 parent 12e9432
commit 4c3de59
Showing 1 changed file with 3 additions and 4 deletions.
diff --git 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_priv *rtlpriv, u32 addr, void *data,
 	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,