Em Wed, 5 Oct 2016 09:50:42 +0200 (CEST) Jiri Kosina <[email protected]> escreveu:
> On Wed, 5 Oct 2016, Patrick Boettcher wrote: > > > > > Thanks for the quick response. > > > > Drivers are: > > > > dvb_core, dvb_usb, dbv_usb_cynergyT2 > > > > > > This dbv_usb_cynergyT2 is not from Linus' tree, is it? I don't seem > > > to be able to find it, and the only google hit I am getting is your > > > very mail to LKML :) > > > > It's a typo, it should say dvb_usb_cinergyT2. > > Ah, thanks. Same issues there in > > cinergyt2_frontend_attach() > cinergyt2_rc_query() > > I think this would require more in-depth review of all the media drivers > and having all this fixed for 4.9. It should be pretty straightforward; > all the instances I've seen so far should be just straightforward > conversion to kmalloc() + kfree(), as the buffer is not being embedded in > any structure etc. What we're doing on most cases is to put a buffer (usually with 80 chars for USB drivers) inside the "state" struct (on DVB drivers), in order to avoid doing kmalloc/kfree all the times. One such patch is changeset c4a98793a63c4. I'm enclosing a non-tested patch fixing it for the cinergyT2-core.c driver. Thanks, Mauro [PATCH] cinergyT2-core: 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. Signed-off-by: Mauro Carvalho Chehab <[email protected]> diff --git a/drivers/media/usb/dvb-usb/cinergyT2-core.c b/drivers/media/usb/dvb-usb/cinergyT2-core.c index 9fd1527494eb..2787acc74fcc 100644 --- a/drivers/media/usb/dvb-usb/cinergyT2-core.c +++ b/drivers/media/usb/dvb-usb/cinergyT2-core.c @@ -41,6 +41,7 @@ DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nr); struct cinergyt2_state { u8 rc_counter; + unsigned char data[64]; }; /* We are missing a release hook with usb_device data */ @@ -50,29 +51,34 @@ static struct dvb_usb_device_properties cinergyt2_properties; static int cinergyt2_streaming_ctrl(struct dvb_usb_adapter *adap, int enable) { - char buf[] = { CINERGYT2_EP1_CONTROL_STREAM_TRANSFER, enable ? 1 : 0 }; - char result[64]; - return dvb_usb_generic_rw(adap->dev, buf, sizeof(buf), result, - sizeof(result), 0); + struct dvb_usb_device *d = adap->dev; + struct cinergyt2_state *st = d->priv; + + st->data[0] = CINERGYT2_EP1_CONTROL_STREAM_TRANSFER; + st->data[1] = enable ? 1 : 0; + + return dvb_usb_generic_rw(d, st->data, 2, st->data, 64, 0); } static int cinergyt2_power_ctrl(struct dvb_usb_device *d, int enable) { - char buf[] = { CINERGYT2_EP1_SLEEP_MODE, enable ? 0 : 1 }; - char state[3]; - return dvb_usb_generic_rw(d, buf, sizeof(buf), state, sizeof(state), 0); + struct cinergyt2_state *st = d->priv; + + st->data[0] = CINERGYT2_EP1_SLEEP_MODE; + st->data[1] = enable ? 1 : 0; + + return dvb_usb_generic_rw(d, st->data, 2, st->data, 3, 0); } static int cinergyt2_frontend_attach(struct dvb_usb_adapter *adap) { - char query[] = { CINERGYT2_EP1_GET_FIRMWARE_VERSION }; - char state[3]; + struct dvb_usb_device *d = adap->dev; + struct cinergyt2_state *st = d->priv; int ret; adap->fe_adap[0].fe = cinergyt2_fe_attach(adap->dev); - ret = dvb_usb_generic_rw(adap->dev, query, sizeof(query), state, - sizeof(state), 0); + ret = dvb_usb_generic_rw(d, st->data, 1, st->data, 3, 0); if (ret < 0) { deb_rc("cinergyt2_power_ctrl() Failed to retrieve sleep " "state info\n"); @@ -141,13 +147,14 @@ static int repeatable_keys[] = { static int cinergyt2_rc_query(struct dvb_usb_device *d, u32 *event, int *state) { struct cinergyt2_state *st = d->priv; - u8 key[5] = {0, 0, 0, 0, 0}, cmd = CINERGYT2_EP1_GET_RC_EVENTS; int i; *state = REMOTE_NO_KEY_PRESSED; - dvb_usb_generic_rw(d, &cmd, 1, key, sizeof(key), 0); - if (key[4] == 0xff) { + st->data[0] = CINERGYT2_EP1_SLEEP_MODE; + + dvb_usb_generic_rw(d, st->data, 1, st->data, 5, 0); + if (st->data[4] == 0xff) { /* key repeat */ st->rc_counter++; if (st->rc_counter > RC_REPEAT_DELAY) { @@ -166,13 +173,13 @@ static int cinergyt2_rc_query(struct dvb_usb_device *d, u32 *event, int *state) } /* hack to pass checksum on the custom field */ - key[2] = ~key[1]; - dvb_usb_nec_rc_key_to_event(d, key, event, state); - if (key[0] != 0) { + st->data[2] = ~st->data[1]; + dvb_usb_nec_rc_key_to_event(d, st->data, event, state); + if (st->data[0] != 0) { if (*event != d->last_event) st->rc_counter = 0; - deb_rc("key: %*ph\n", 5, key); + deb_rc("key: %*ph\n", 5, st->data); } return 0; }
