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Commit 88ca3619 authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
Browse files

[media] technisat-usb2: use DMA buffers for I2C transfers 



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.

Reviewed-by: default avatarPatrick Boettcher <patrick.boettcher@posteo.de>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
parent 5dfd2c8f

drivers/media/usb/dvb-usb/technisat-usb2.c

+11 −5
Original line number Diff line number Diff line
@@ -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,