diff options
| author | Stefan Brüns <stefan.bruens@rwth-aachen.de> | 2017-02-05 17:57:59 +0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2017-02-08 16:52:40 +0300 |
| commit | 3f190e3aec212fc8c61e202c51400afa7384d4bc (patch) | |
| tree | 56edab612463b64d0cb0428820c1074e6e0ce3d8 /drivers/media | |
| parent | 69d3973af1acd4c0989ec8218c05f12d303cd7cf (diff) | |
| download | linux-3f190e3aec212fc8c61e202c51400afa7384d4bc.tar.xz | |
[media] cxusb: Use a dma capable buffer also for reading
Commit 17ce039b4e54 ("[media] cxusb: don't do DMA on stack")
added a kmalloc'ed bounce buffer for writes, but missed to do the same
for reads. As the read only happens after the write is finished, we can
reuse the same buffer.
As dvb_usb_generic_rw handles a read length of 0 by itself, avoid calling
it using the dvb_usb_generic_read wrapper function.
Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Diffstat (limited to 'drivers/media')
| -rw-r--r-- | drivers/media/usb/dvb-usb/cxusb.c | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/drivers/media/usb/dvb-usb/cxusb.c b/drivers/media/usb/dvb-usb/cxusb.c index 5d7b4eaa6a3c..51620e02292f 100644 --- a/drivers/media/usb/dvb-usb/cxusb.c +++ b/drivers/media/usb/dvb-usb/cxusb.c @@ -59,23 +59,24 @@ static int cxusb_ctrl_msg(struct dvb_usb_device *d, u8 cmd, u8 *wbuf, int wlen, u8 *rbuf, int rlen) { struct cxusb_state *st = d->priv; - int ret, wo; + int ret; if (1 + wlen > MAX_XFER_SIZE) { warn("i2c wr: len=%d is too big!\n", wlen); return -EOPNOTSUPP; } - wo = (rbuf == NULL || rlen == 0); /* write-only */ + if (rlen > MAX_XFER_SIZE) { + warn("i2c rd: len=%d is too big!\n", rlen); + return -EOPNOTSUPP; + } mutex_lock(&d->data_mutex); st->data[0] = cmd; memcpy(&st->data[1], wbuf, wlen); - if (wo) - ret = dvb_usb_generic_write(d, st->data, 1 + wlen); - else - ret = dvb_usb_generic_rw(d, st->data, 1 + wlen, - rbuf, rlen, 0); + ret = dvb_usb_generic_rw(d, st->data, 1 + wlen, st->data, rlen, 0); + if (!ret && rbuf && rlen) + memcpy(rbuf, st->data, rlen); mutex_unlock(&d->data_mutex); return ret; |