On Fri, 7 Oct 2016 14:24:16 -0300 Mauro Carvalho Chehab <[email protected]> wrote:
> 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 <[email protected]> > --- > drivers/media/usb/dvb-usb/cxusb.c | 20 +++++++------------- > drivers/media/usb/dvb-usb/cxusb.h | 5 +++++ > 2 files changed, 12 insertions(+), 13 deletions(-) > > diff --git a/drivers/media/usb/dvb-usb/cxusb.c > b/drivers/media/usb/dvb-usb/cxusb.c index 907ac01ae297..f3615349de52 > 100644 --- a/drivers/media/usb/dvb-usb/cxusb.c > +++ b/drivers/media/usb/dvb-usb/cxusb.c > @@ -45,9 +45,6 @@ > #include "si2168.h" > #include "si2157.h" > > -/* Max transfer size done by I2C transfer functions */ > -#define MAX_XFER_SIZE 80 > - > /* debug */ > static int dvb_usb_cxusb_debug; > module_param_named(debug, dvb_usb_cxusb_debug, int, 0644); > @@ -61,23 +58,20 @@ DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nr); > 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 wo = (rbuf == NULL || rlen == 0); /* write-only */ > - u8 sndbuf[MAX_XFER_SIZE]; > > - if (1 + wlen > sizeof(sndbuf)) { > - warn("i2c wr: len=%d is too big!\n", > - wlen); > + if (1 + wlen > MAX_XFER_SIZE) { > + warn("i2c wr: len=%d is too big!\n", wlen); > return -EOPNOTSUPP; > } > > - memset(sndbuf, 0, 1+wlen); > - > - sndbuf[0] = cmd; > - memcpy(&sndbuf[1], wbuf, wlen); > + st->data[0] = cmd; > + memcpy(&st->data[1], wbuf, wlen); > if (wo) > - return dvb_usb_generic_write(d, sndbuf, 1+wlen); > + return dvb_usb_generic_write(d, st->data, 1 + wlen); > else > - return dvb_usb_generic_rw(d, sndbuf, 1+wlen, rbuf, > rlen, 0); > + return dvb_usb_generic_rw(d, st->data, 1 + wlen, > rbuf, rlen, 0); } > > /* GPIO */ > diff --git a/drivers/media/usb/dvb-usb/cxusb.h > b/drivers/media/usb/dvb-usb/cxusb.h index 527ff7905e15..18acda19527a > 100644 --- a/drivers/media/usb/dvb-usb/cxusb.h > +++ b/drivers/media/usb/dvb-usb/cxusb.h > @@ -28,10 +28,15 @@ > #define CMD_ANALOG 0x50 > #define CMD_DIGITAL 0x51 > > +/* Max transfer size done by I2C transfer functions */ > +#define MAX_XFER_SIZE 80 > + > struct cxusb_state { > u8 gpio_write_state[3]; > struct i2c_client *i2c_client_demod; > struct i2c_client *i2c_client_tuner; > + > + unsigned char data[MAX_XFER_SIZE]; > }; > > #endif Reviewed-By: Patrick Boettcher <[email protected]>
