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authorJohan Hovold <jhovold@gmail.com>2013-05-27 14:44:40 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-05-29 10:50:42 +0900
commit15ee89c3347fbf58a4361011eda5ac2731e45126 (patch)
tree6b3c9f3e7165a27919b9e7f350695cdc2308b923 /drivers
parent72ea18a558ed7a63a50bb121ba60d73b5b38ae30 (diff)
USB: mos7840: fix DMA to stack
Fix regression introduced by commit 0eafe4de1a ("USB: serial: mos7840: add support for MCS7810 devices") which used stack-allocated buffers for control messages. Cc: stable@vger.kernel.org Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/usb/serial/mos7840.c35
1 files changed, 27 insertions, 8 deletions
diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c
index a0d5ea545982..7e998081e1cd 100644
--- a/drivers/usb/serial/mos7840.c
+++ b/drivers/usb/serial/mos7840.c
@@ -2142,13 +2142,21 @@ static int mos7840_ioctl(struct tty_struct *tty,
static int mos7810_check(struct usb_serial *serial)
{
int i, pass_count = 0;
+ u8 *buf;
__u16 data = 0, mcr_data = 0;
__u16 test_pattern = 0x55AA;
+ int res;
+
+ buf = kmalloc(VENDOR_READ_LENGTH, GFP_KERNEL);
+ if (!buf)
+ return 0; /* failed to identify 7810 */
/* Store MCR setting */
- usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
+ res = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
MCS_RDREQ, MCS_RD_RTYPE, 0x0300, MODEM_CONTROL_REGISTER,
- &mcr_data, VENDOR_READ_LENGTH, MOS_WDR_TIMEOUT);
+ buf, VENDOR_READ_LENGTH, MOS_WDR_TIMEOUT);
+ if (res == VENDOR_READ_LENGTH)
+ mcr_data = *buf;
for (i = 0; i < 16; i++) {
/* Send the 1-bit test pattern out to MCS7810 test pin */
@@ -2158,9 +2166,12 @@ static int mos7810_check(struct usb_serial *serial)
MODEM_CONTROL_REGISTER, NULL, 0, MOS_WDR_TIMEOUT);
/* Read the test pattern back */
- usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
- MCS_RDREQ, MCS_RD_RTYPE, 0, GPIO_REGISTER, &data,
- VENDOR_READ_LENGTH, MOS_WDR_TIMEOUT);
+ res = usb_control_msg(serial->dev,
+ usb_rcvctrlpipe(serial->dev, 0), MCS_RDREQ,
+ MCS_RD_RTYPE, 0, GPIO_REGISTER, buf,
+ VENDOR_READ_LENGTH, MOS_WDR_TIMEOUT);
+ if (res == VENDOR_READ_LENGTH)
+ data = *buf;
/* If this is a MCS7810 device, both test patterns must match */
if (((test_pattern >> i) ^ (~data >> 1)) & 0x0001)
@@ -2174,6 +2185,8 @@ static int mos7810_check(struct usb_serial *serial)
MCS_WR_RTYPE, 0x0300 | mcr_data, MODEM_CONTROL_REGISTER, NULL,
0, MOS_WDR_TIMEOUT);
+ kfree(buf);
+
if (pass_count == 16)
return 1;
@@ -2183,11 +2196,17 @@ static int mos7810_check(struct usb_serial *serial)
static int mos7840_calc_num_ports(struct usb_serial *serial)
{
__u16 data = 0x00;
+ u8 *buf;
int mos7840_num_ports;
- usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
- MCS_RDREQ, MCS_RD_RTYPE, 0, GPIO_REGISTER, &data,
- VENDOR_READ_LENGTH, MOS_WDR_TIMEOUT);
+ buf = kzalloc(VENDOR_READ_LENGTH, GFP_KERNEL);
+ if (buf) {
+ usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
+ MCS_RDREQ, MCS_RD_RTYPE, 0, GPIO_REGISTER, buf,
+ VENDOR_READ_LENGTH, MOS_WDR_TIMEOUT);
+ data = *buf;
+ kfree(buf);
+ }
if (serial->dev->descriptor.idProduct == MOSCHIP_DEVICE_ID_7810 ||
serial->dev->descriptor.idProduct == MOSCHIP_DEVICE_ID_7820) {