Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752327AbcJJGfw (ORCPT ); Mon, 10 Oct 2016 02:35:52 -0400 Received: from mout02.posteo.de ([185.67.36.66]:48606 "EHLO mout02.posteo.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751865AbcJJGfv (ORCPT ); Mon, 10 Oct 2016 02:35:51 -0400 Date: Mon, 10 Oct 2016 08:35:47 +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 19/26] nova-t-usb2: don't do DMA on stack Message-ID: <20161010083547.78996d0f@posteo.de> In-Reply-To: References: 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: 2170 Lines: 65 On Fri, 7 Oct 2016 14:24:29 -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/nova-t-usb2.c | 18 +++++++++++++----- > 1 file changed, 13 insertions(+), 5 deletions(-) > > diff --git a/drivers/media/usb/dvb-usb/nova-t-usb2.c > b/drivers/media/usb/dvb-usb/nova-t-usb2.c index > fc7569e2728d..26d7188a1163 100644 --- > a/drivers/media/usb/dvb-usb/nova-t-usb2.c +++ > b/drivers/media/usb/dvb-usb/nova-t-usb2.c @@ -74,22 +74,29 @@ static > struct rc_map_table rc_map_haupp_table[] = { */ > static int nova_t_rc_query(struct dvb_usb_device *d, u32 *event, int > *state) { > - u8 key[5],cmd[2] = { DIBUSB_REQ_POLL_REMOTE, 0x35 }, > data,toggle,custom; > + u8 *buf, data, toggle, custom; > u16 raw; > int i; > struct dibusb_device_state *st = d->priv; > > - dvb_usb_generic_rw(d,cmd,2,key,5,0); > + buf = kmalloc(5, GFP_KERNEL); > + if (!buf) > + return -ENOMEM; > + > + buf[0] = DIBUSB_REQ_POLL_REMOTE; > + buf[1] = 0x35; > + dvb_usb_generic_rw(d, buf, 2, buf, 5, 0); > > *state = REMOTE_NO_KEY_PRESSED; > - switch (key[0]) { > + switch (buf[0]) { > case DIBUSB_RC_HAUPPAUGE_KEY_PRESSED: > - raw = ((key[1] << 8) | key[2]) >> 3; > + raw = ((buf[1] << 8) | buf[2]) >> 3; > toggle = !!(raw & 0x800); > data = raw & 0x3f; > custom = (raw >> 6) & 0x1f; > > - deb_rc("raw key code 0x%02x, 0x%02x, 0x%02x > to c: %02x d: %02x toggle: > %d\n",key[1],key[2],key[3],custom,data,toggle); > + deb_rc("raw key code 0x%02x, 0x%02x, 0x%02x > to c: %02x d: %02x toggle: %d\n", > + buf[1], buf[2], buf[3], custom, data, > toggle); > for (i = 0; i < > ARRAY_SIZE(rc_map_haupp_table); i++) { if > (rc5_data(&rc_map_haupp_table[i]) == data && @@ -117,6 +124,7 @@ > static int nova_t_rc_query(struct dvb_usb_device *d, u32 *event, int > *state) break; } > > + kfree(buf); > return 0; > } > Reviewed-By: Patrick Boettcher