[PATCH 20/37] Input: usbtouchscreen - don't use DMA on stack

From: Oliver Neukum
Date: Mon Apr 21 2008 - 09:30:33 EST


DMA on the stack is not allowed. The buffer must be kmalloced.

Signed-off-by: Oliver Neukum <oneukum@xxxxxxx>
Signed-off-by: Dmitry Torokhov <dtor@xxxxxxx>
---
drivers/input/touchscreen/usbtouchscreen.c | 31 +++++++++++++++++----------
1 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/drivers/input/touchscreen/usbtouchscreen.c b/drivers/input/touchscreen/usbtouchscreen.c
index 63f9664..3a0a8ca 100644
--- a/drivers/input/touchscreen/usbtouchscreen.c
+++ b/drivers/input/touchscreen/usbtouchscreen.c
@@ -396,9 +396,12 @@ static int gunze_read_data(struct usbtouch_usb *dev, unsigned char *pkt)
static int dmc_tsc10_init(struct usbtouch_usb *usbtouch)
{
struct usb_device *dev = usbtouch->udev;
- int ret;
- unsigned char buf[2];
+ int ret = -ENOMEM;
+ unsigned char *buf;

+ buf = kmalloc(2, GFP_KERNEL);
+ if (!buf)
+ goto err_nobuf;
/* reset */
buf[0] = buf[1] = 0xFF;
ret = usb_control_msg(dev, usb_rcvctrlpipe (dev, 0),
@@ -406,9 +409,11 @@ static int dmc_tsc10_init(struct usbtouch_usb *usbtouch)
USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
0, 0, buf, 2, USB_CTRL_SET_TIMEOUT);
if (ret < 0)
- return ret;
- if (buf[0] != 0x06 || buf[1] != 0x00)
- return -ENODEV;
+ goto err_out;
+ if (buf[0] != 0x06 || buf[1] != 0x00) {
+ ret = -ENODEV;
+ goto err_out;
+ }

/* set coordinate output rate */
buf[0] = buf[1] = 0xFF;
@@ -417,20 +422,22 @@ static int dmc_tsc10_init(struct usbtouch_usb *usbtouch)
USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
TSC10_RATE_150, 0, buf, 2, USB_CTRL_SET_TIMEOUT);
if (ret < 0)
- return ret;
+ goto err_out;
if ((buf[0] != 0x06 || buf[1] != 0x00) &&
- (buf[0] != 0x15 || buf[1] != 0x01))
- return -ENODEV;
+ (buf[0] != 0x15 || buf[1] != 0x01)) {
+ ret = -ENODEV;
+ goto err_out;
+ }

/* start sending data */
ret = usb_control_msg(dev, usb_rcvctrlpipe (dev, 0),
TSC10_CMD_DATA1,
USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
0, 0, NULL, 0, USB_CTRL_SET_TIMEOUT);
- if (ret < 0)
- return ret;
-
- return 0;
+err_out:
+ kfree(buf);
+err_nobuf:
+ return ret;
}


--
1.5.5.rc2.6.gf58d


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