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authorMauro Carvalho Chehab <mchehab@s-opensource.com>2016-10-07 12:04:38 -0300
committerMauro Carvalho Chehab <mchehab@s-opensource.com>2016-10-14 12:47:35 -0300
commit88ca3619001380a3147246a22cb356f6065ad713 (patch)
tree1b405c686d021f505b22f0675dd57f60e517fc87
parent5dfd2c8f263dfcaf614d24734f0af8c1c18a9ca8 (diff)
[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: Patrick Boettcher <patrick.boettcher@posteo.de> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
-rw-r--r--drivers/media/usb/dvb-usb/technisat-usb2.c16
1 files 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,

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