[PATCH 3.16 080/328] media: gl861: fix probe of dvb_usb_gl861

Ben Hutchings
2018-12-09T22:10:17Z

From: Mika Båtsman <mika.batsman@gmail.com>

commit 48db0089bff6f9154f6bd98ce7a6ae3786fa8ebe upstream.

Probe of dvb_usb_gl861 was working at least with v4.4. Noticed the issue
with v4.13 but according to similar issues the problem started with v4.9.

[ 15.288065] transfer buffer not dma capable
[ 15.288090] WARNING: CPU: 2 PID: 493 at drivers/usb/core/hcd.c:1595 usb_hcd_map_urb_for_dma+0x4e2/0x640
...CUT...
[ 15.288791] dvb_usb_gl861: probe of 3-7:1.0 failed with error -5

Tested with MSI Mega Sky 580 DVB-T Tuner [GL861]

[mchehab+samsung@kernel.org: rebased on the top of upstream]
Signed-off-by: Mika Båtsman <mika.batsman@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/media/usb/dvb-usb-v2/gl861.c | 21 ++++++++++-----------
1 file changed, 10 insertions(+), 11 deletions(-)

--- a/drivers/media/usb/dvb-usb-v2/gl861.c
+++ b/drivers/media/usb/dvb-usb-v2/gl861.c
@@ -26,10 +26,14 @@ static int gl861_i2c_msg(struct dvb_usb_
if (wo) {
req = GL861_REQ_I2C_WRITE;
type = GL861_WRITE;
+ buf = kmemdup(wbuf, wlen, GFP_KERNEL);
} else { /* rw */
req = GL861_REQ_I2C_READ;
type = GL861_READ;
+ buf = kmalloc(rlen, GFP_KERNEL);
}
+ if (!buf)
+ return -ENOMEM;

switch (wlen) {
case 1:
@@ -42,24 +46,19 @@ static int gl861_i2c_msg(struct dvb_usb_
default:
dev_err(&d->udev->dev, "%s: wlen=%d, aborting\n",
KBUILD_MODNAME, wlen);
+ kfree(buf);
return -EINVAL;
}
- buf = NULL;
- if (rlen > 0) {
- buf = kmalloc(rlen, GFP_KERNEL);
- if (!buf)
- return -ENOMEM;
- }
+
msleep(1); /* avoid I2C errors */

ret = usb_control_msg(d->udev, usb_rcvctrlpipe(d->udev, 0), req, type,
value, index, buf, rlen, 2000);
- if (rlen > 0) {
- if (ret > 0)
- memcpy(rbuf, buf, rlen);
- kfree(buf);
- }

+ if (!wo && ret > 0)
+ memcpy(rbuf, buf, rlen);
+
+ kfree(buf);
return ret;
}