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[media] digitv: don't do DMA on stack 

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>
This commit is contained in:
Mauro Carvalho Chehab 2016-10-07 07:55:38 -03:00
parent ff1c123545
commit f0b0ada718
2 changed files with 15 additions and 10 deletions
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20
drivers/media/usb/dvb-usb/digitv.c
View File

@ -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;
}

5
drivers/media/usb/dvb-usb/digitv.h
View File

@ -5,7 +5,10 @@
#include "dvb-usb.h"
struct digitv_state {
int is_nxt6000;
int is_nxt6000;
unsigned char sndbuf[7];
unsigned char rcvbuf[7];
};
/* protocol (from usblogging and the SDK: