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Subject[PATCH v2 20/31] nova-t-usb2: don't do DMA on stack
Date
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.

Reviewed-By: Patrick Boettcher <patrick.boettcher@posteo.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
---
drivers/media/usb/dvb-usb/nova-t-usb2.c | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/media/usb/dvb-usb/nova-t-usb2.c b/drivers/media/usb/dvb-usb/nova-t-usb2.c
index fc7569e2728d..26d7188a1163 100644
--- a/drivers/media/usb/dvb-usb/nova-t-usb2.c
+++ b/drivers/media/usb/dvb-usb/nova-t-usb2.c
@@ -74,22 +74,29 @@ static struct rc_map_table rc_map_haupp_table[] = {
*/
static int nova_t_rc_query(struct dvb_usb_device *d, u32 *event, int *state)
{
- u8 key[5],cmd[2] = { DIBUSB_REQ_POLL_REMOTE, 0x35 }, data,toggle,custom;
+ u8 *buf, data, toggle, custom;
u16 raw;
int i;
struct dibusb_device_state *st = d->priv;

- dvb_usb_generic_rw(d,cmd,2,key,5,0);
+ buf = kmalloc(5, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ buf[0] = DIBUSB_REQ_POLL_REMOTE;
+ buf[1] = 0x35;
+ dvb_usb_generic_rw(d, buf, 2, buf, 5, 0);

*state = REMOTE_NO_KEY_PRESSED;
- switch (key[0]) {
+ switch (buf[0]) {
case DIBUSB_RC_HAUPPAUGE_KEY_PRESSED:
- raw = ((key[1] << 8) | key[2]) >> 3;
+ raw = ((buf[1] << 8) | buf[2]) >> 3;
toggle = !!(raw & 0x800);
data = raw & 0x3f;
custom = (raw >> 6) & 0x1f;

- deb_rc("raw key code 0x%02x, 0x%02x, 0x%02x to c: %02x d: %02x toggle: %d\n",key[1],key[2],key[3],custom,data,toggle);
+ deb_rc("raw key code 0x%02x, 0x%02x, 0x%02x to c: %02x d: %02x toggle: %d\n",
+ buf[1], buf[2], buf[3], custom, data, toggle);

for (i = 0; i < ARRAY_SIZE(rc_map_haupp_table); i++) {
if (rc5_data(&rc_map_haupp_table[i]) == data &&
@@ -117,6 +124,7 @@ static int nova_t_rc_query(struct dvb_usb_device *d, u32 *event, int *state)
break;
}

+ kfree(buf);
return 0;
}

--
2.7.4

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