Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752299AbcJJGjy (ORCPT ); Mon, 10 Oct 2016 02:39:54 -0400 Received: from mout02.posteo.de ([185.67.36.66]:34583 "EHLO mout02.posteo.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752107AbcJJGjx (ORCPT ); Mon, 10 Oct 2016 02:39:53 -0400 Date: Mon, 10 Oct 2016 08:39:34 +0200 From: Patrick Boettcher To: Mauro Carvalho Chehab Cc: Linux Media Mailing List , Mauro Carvalho Chehab , Andy Lutomirski , Johannes Stezenbach , Jiri Kosina , Linux Kernel Mailing List , Andy Lutomirski , Michael Krufky , Mauro Carvalho Chehab , =?UTF-8?B?SsO2cmc=?= Otte Subject: Re: [PATCH 02/26] cinergyT2-core: don't do DMA on stack Message-ID: <20161010083934.34bacb3b@posteo.de> In-Reply-To: <9589abc05caa366003d399d6f3fe5a5ca2ab8c97.1475860773.git.mchehab@s-opensource.com> References: <9589abc05caa366003d399d6f3fe5a5ca2ab8c97.1475860773.git.mchehab@s-opensource.com> X-Mailer: Claws Mail 3.14.0 (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3855 Lines: 115 On Fri, 7 Oct 2016 14:24:12 -0300 Mauro Carvalho Chehab 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 > --- > drivers/media/usb/dvb-usb/cinergyT2-core.c | 45 > ++++++++++++++++++------------ 1 file changed, 27 insertions(+), 18 > deletions(-) > > diff --git a/drivers/media/usb/dvb-usb/cinergyT2-core.c > b/drivers/media/usb/dvb-usb/cinergyT2-core.c index > 9fd1527494eb..91640c927776 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 +51,36 @@ 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 ? 0 : 1; > + > + 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); > + st->data[0] = CINERGYT2_EP1_GET_FIRMWARE_VERSION; > + > + 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 +149,14 @@ 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_GET_RC_EVENTS; > + > + 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 +175,13 @@ 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; > } Reviewed-By: Patrick Boettcher