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Subject[PATCH v2 11/31] digitv: 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/digitv.c | 20 +++++++++++---------
drivers/media/usb/dvb-usb/digitv.h | 3 +++
2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/drivers/media/usb/dvb-usb/digitv.c b/drivers/media/usb/dvb-usb/digitv.c
index 63134335c994..09f8c28bd4db 100644
--- a/drivers/media/usb/dvb-usb/digitv.c
+++ b/drivers/media/usb/dvb-usb/digitv.c
@@ -28,20 +28,22 @@ DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nr);
static int digitv_ctrl_msg(struct dvb_usb_device *d,
u8 cmd, u8 vv, u8 *wbuf, int wlen, u8 *rbuf, int rlen)
{
+ struct digitv_state *st = d->priv;
int wo = (rbuf == NULL || rlen == 0); /* write-only */
- u8 sndbuf[7],rcvbuf[7];
- memset(sndbuf,0,7); memset(rcvbuf,0,7);

- sndbuf[0] = cmd;
- sndbuf[1] = vv;
- sndbuf[2] = wo ? wlen : rlen;
+ memset(st->sndbuf, 0, 7);
+ memset(st->rcvbuf, 0, 7);
+
+ st->sndbuf[0] = cmd;
+ st->sndbuf[1] = vv;
+ st->sndbuf[2] = wo ? wlen : rlen;

if (wo) {
- memcpy(&sndbuf[3],wbuf,wlen);
- dvb_usb_generic_write(d,sndbuf,7);
+ memcpy(&st->sndbuf[3], wbuf, wlen);
+ dvb_usb_generic_write(d, st->sndbuf, 7);
} else {
- dvb_usb_generic_rw(d,sndbuf,7,rcvbuf,7,10);
- memcpy(rbuf,&rcvbuf[3],rlen);
+ dvb_usb_generic_rw(d, st->sndbuf, 7, st->rcvbuf, 7, 10);
+ memcpy(rbuf, &st->rcvbuf[3], rlen);
}
return 0;
}
diff --git a/drivers/media/usb/dvb-usb/digitv.h b/drivers/media/usb/dvb-usb/digitv.h
index 908c09f4966b..cf104689bdff 100644
--- a/drivers/media/usb/dvb-usb/digitv.h
+++ b/drivers/media/usb/dvb-usb/digitv.h
@@ -6,6 +6,9 @@

struct digitv_state {
int is_nxt6000;
+
+ unsigned char sndbuf[7];
+ unsigned char rcvbuf[7];
};

/* protocol (from usblogging and the SDK:
--
2.7.4

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