On 12/20/2012 08:24 AM, Jussi Kivilinna wrote:
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: stable@xxxxxxxxxxxxxxx Signed-off-by: Jussi Kivilinna <jussi.kivilinna@xxxxxxxx> --- drivers/net/wireless/rtlwifi/usb.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)
Acked-by: Larry Finger <Larry.Finger@xxxxxxxxxxxx> Thanks. My only test platforms are X86 and PPC-32. Neither showed this problem. Larry
diff --git a/drivers/net/wireless/rtlwifi/usb.c b/drivers/net/wireless/rtlwifi/usb.c index 29f0969..a3312b7 100644 --- 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, -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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