On Fri, 7 Oct 2016 14:24:32 -0300
Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx> wrote:
> The USB control messages require DMA to work. We cannot pass
> a stack-allocated buffer, as it is not warranted that the
> stack would be into a DMA enabled area.
>
> On this driver, most of the transfers are OK, but the I2C
> one was using stack.
>
> Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
> ---
> drivers/media/usb/dvb-usb/technisat-usb2.c | 16 +++++++++++-----
> 1 file changed, 11 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/media/usb/dvb-usb/technisat-usb2.c
> b/drivers/media/usb/dvb-usb/technisat-usb2.c index
> d9f3262bf071..4706628a3ed5 100644 ---
> a/drivers/media/usb/dvb-usb/technisat-usb2.c +++
> b/drivers/media/usb/dvb-usb/technisat-usb2.c @@ -89,9 +89,13 @@
> struct technisat_usb2_state { static int
> technisat_usb2_i2c_access(struct usb_device *udev, u8 device_addr, u8
> *tx, u8 txlen, u8 *rx, u8 rxlen) {
> - u8 b[64];
> + u8 *b;
> int ret, actual_length;
>
> + b = kmalloc(64, GFP_KERNEL);
> + if (!b)
> + return -ENOMEM;
> +
> deb_i2c("i2c-access: %02x, tx: ", device_addr);
> debug_dump(tx, txlen, deb_i2c);
> deb_i2c(" ");
> @@ -123,7 +127,7 @@ static int technisat_usb2_i2c_access(struct
> usb_device *udev,
> if (ret < 0) {
> err("i2c-error: out failed %02x = %d", device_addr,
> ret);
> - return -ENODEV;
> + goto err;
> }
>
> ret = usb_bulk_msg(udev,
> @@ -131,7 +135,7 @@ static int technisat_usb2_i2c_access(struct
> usb_device *udev, b, 64, &actual_length, 1000);
> if (ret < 0) {
> err("i2c-error: in failed %02x = %d", device_addr,
> ret);
> - return -ENODEV;
> + goto err;
> }
>
> if (b[0] != I2C_STATUS_OK) {
> @@ -140,7 +144,7 @@ static int technisat_usb2_i2c_access(struct
> usb_device *udev, if (!(b[0] == I2C_STATUS_NAK &&
> device_addr == 0x60
> /* && device_is_technisat_usb2 */))
> - return -ENODEV;
> + goto err;
> }
>
> deb_i2c("status: %d, ", b[0]);
> @@ -154,7 +158,9 @@ static int technisat_usb2_i2c_access(struct
> usb_device *udev,
> deb_i2c("\n");
>
> - return 0;
> +err:
> + kfree(b);
> + return ret;
> }
>
> static int technisat_usb2_i2c_xfer(struct i2c_adapter *adap, struct
> i2c_msg *msg,
Reviewed-By: Patrick Boettcher <patrick.boettcher@xxxxxxxxx>
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