Re: [PATCH] zd1211rw: Use DMA-aware buffer for usb transfer
From: Atsushi Nemoto
Date: Fri May 16 2008 - 04:27:30 EST
On Thu, 15 May 2008 15:16:47 -0400, "John W. Linville" <linville@xxxxxxxxxxxxx> wrote:
> This looks like a reasonable fix to me. I would prefer to see a
> comment in the code indicating why you are reusing the "p" buffer
> instead of simply using "ret" directly. Also, I think the style
> suggestion by Michael Buesch would make the code appear more idiomatic
> as well.
OK, revised. Thank you for review.
------------------------------------------------------
Subject: [PATCH] zd1211rw: Use DMA-aware buffer for usb transfer
From: Atsushi Nemoto <anemo@xxxxxxxxxxxxx>
The zd1211rw driver uses unaligned stack buffer for USB control
message. But it might cause stack corruption on non-coherent
platform, such as MIPS. Use DMA-aware buffers for USB transfer.
Signed-off-by: Atsushi Nemoto <anemo@xxxxxxxxxxxxx>
---
drivers/net/wireless/zd1211rw/zd_usb.c | 23 +++++++++++++++++------
1 files changed, 17 insertions(+), 6 deletions(-)
diff --git a/drivers/net/wireless/zd1211rw/zd_usb.c b/drivers/net/wireless/zd1211rw/zd_usb.c
index 12e24f0..f9a9a5d 100644
--- a/drivers/net/wireless/zd1211rw/zd_usb.c
+++ b/drivers/net/wireless/zd1211rw/zd_usb.c
@@ -169,10 +169,11 @@ static int upload_code(struct usb_device *udev,
if (flags & REBOOT) {
u8 ret;
+ /* Use "DMA-aware" buffer. */
r = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
USB_REQ_FIRMWARE_CONFIRM,
USB_DIR_IN | USB_TYPE_VENDOR,
- 0, 0, &ret, sizeof(ret), 5000 /* ms */);
+ 0, 0, p, sizeof(ret), 5000 /* ms */);
if (r != sizeof(ret)) {
dev_err(&udev->dev,
"control request firmeware confirmation failed."
@@ -181,6 +182,7 @@ static int upload_code(struct usb_device *udev,
r = -ENODEV;
goto error;
}
+ ret = p[0];
if (ret & 0x80) {
dev_err(&udev->dev,
"Internal error while downloading."
@@ -312,22 +314,31 @@ int zd_usb_read_fw(struct zd_usb *usb, zd_addr_t addr, u8 *data, u16 len)
{
int r;
struct usb_device *udev = zd_usb_to_usbdev(usb);
+ u8 *buf;
+ /* Use "DMA-aware" buffer. */
+ buf = kmalloc(len, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
r = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
USB_REQ_FIRMWARE_READ_DATA, USB_DIR_IN | 0x40, addr, 0,
- data, len, 5000);
+ buf, len, 5000);
if (r < 0) {
dev_err(&udev->dev,
"read over firmware interface failed: %d\n", r);
- return r;
+ goto exit;
} else if (r != len) {
dev_err(&udev->dev,
"incomplete read over firmware interface: %d/%d\n",
r, len);
- return -EIO;
+ r = -EIO;
+ goto exit;
}
-
- return 0;
+ r = 0;
+ memcpy(data, buf, len);
+exit:
+ kfree(buf);
+ return r;
}
#define urb_dev(urb) (&(urb)->dev->dev)
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/