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Subject[PATCH v2 18/31] gp8psk: 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.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
---
drivers/media/usb/dvb-usb/gp8psk.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/media/usb/dvb-usb/gp8psk.c b/drivers/media/usb/dvb-usb/gp8psk.c
index 5d0384dd45b5..fa215ad37f7b 100644
--- a/drivers/media/usb/dvb-usb/gp8psk.c
+++ b/drivers/media/usb/dvb-usb/gp8psk.c
@@ -24,6 +24,10 @@ MODULE_PARM_DESC(debug, "set debugging level (1=info,xfer=2,rc=4 (or-able))." DV

DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nr);

+struct gp8psk_state {
+ unsigned char data[80];
+};
+
static int gp8psk_get_fw_version(struct dvb_usb_device *d, u8 *fw_vers)
{
return (gp8psk_usb_in_op(d, GET_FW_VERS, 0, 0, fw_vers, 6));
@@ -53,17 +57,19 @@ static void gp8psk_info(struct dvb_usb_device *d)

int gp8psk_usb_in_op(struct dvb_usb_device *d, u8 req, u16 value, u16 index, u8 *b, int blen)
{
+ struct gp8psk_state *st = d->priv;
int ret = 0,try = 0;

if ((ret = mutex_lock_interruptible(&d->usb_mutex)))
return ret;

while (ret >= 0 && ret != blen && try < 3) {
+ memcpy(st->data, b, blen);
ret = usb_control_msg(d->udev,
usb_rcvctrlpipe(d->udev,0),
req,
USB_TYPE_VENDOR | USB_DIR_IN,
- value,index,b,blen,
+ value, index, st->data, blen,
2000);
deb_info("reading number %d (ret: %d)\n",try,ret);
try++;
@@ -86,6 +92,7 @@ int gp8psk_usb_in_op(struct dvb_usb_device *d, u8 req, u16 value, u16 index, u8
int gp8psk_usb_out_op(struct dvb_usb_device *d, u8 req, u16 value,
u16 index, u8 *b, int blen)
{
+ struct gp8psk_state *st = d->priv;
int ret;

deb_xfer("out: req. %x, val: %x, ind: %x, buffer: ",req,value,index);
@@ -94,11 +101,12 @@ int gp8psk_usb_out_op(struct dvb_usb_device *d, u8 req, u16 value,
if ((ret = mutex_lock_interruptible(&d->usb_mutex)))
return ret;

+ memcpy(st->data, b, blen);
if (usb_control_msg(d->udev,
usb_sndctrlpipe(d->udev,0),
req,
USB_TYPE_VENDOR | USB_DIR_OUT,
- value,index,b,blen,
+ value,index, st->data, blen,
2000) != blen) {
warn("usb out operation failed.");
ret = -EIO;
@@ -265,6 +273,8 @@ static struct dvb_usb_device_properties gp8psk_properties = {
.usb_ctrl = CYPRESS_FX2,
.firmware = "dvb-usb-gp8psk-01.fw",

+ .size_of_priv = sizeof(struct gp8psk_state),
+
.num_adapters = 1,
.adapter = {
{
--
2.7.4

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