Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757263Ab1CRRUV (ORCPT ); Fri, 18 Mar 2011 13:20:21 -0400 Received: from mail.kapsi.fi ([217.30.184.167]:41234 "EHLO mail.kapsi.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757214Ab1CRRUQ (ORCPT ); Fri, 18 Mar 2011 13:20:16 -0400 Message-ID: <4D838A25.8010301@iki.fi> Date: Fri, 18 Mar 2011 18:36:53 +0200 From: Antti Palosaari User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.15) Gecko/20110307 Fedora/3.1.9-0.39.b3pre.fc14 Thunderbird/3.1.9 MIME-Version: 1.0 To: Florian Mickler CC: mchehab@infradead.org, oliver@neukum.org, jwjstone@fastmail.fm, linux-kernel@vger.kernel.org, Mauro Carvalho Chehab , linux-media@vger.kernel.org Subject: Re: [PATCH 05/16] [media] ec168: get rid of on stack dma buffers References: <20110315093632.5fc9fb77@schatten.dmk.lab> <1300178655-24832-1-git-send-email-florian@mickler.org> <1300178655-24832-5-git-send-email-florian@mickler.org> In-Reply-To: <1300178655-24832-5-git-send-email-florian@mickler.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 82.128.184.4 X-SA-Exim-Mail-From: crope@iki.fi X-SA-Exim-Scanned: No (on mail.kapsi.fi); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2669 Lines: 87 On 03/15/2011 10:43 AM, Florian Mickler wrote: > usb_control_msg initiates (and waits for completion of) a dma transfer using > the supplied buffer. That buffer thus has to be seperately allocated on > the heap. > > In lib/dma_debug.c the function check_for_stack even warns about it: > WARNING: at lib/dma-debug.c:866 check_for_stack > > Note: This change is tested to compile only, as I don't have the hardware. > > Signed-off-by: Florian Mickler Acked-by: Antti Palosaari Reviewed-by: Antti Palosaari Tested-by: Antti Palosaari t. Antti > --- > drivers/media/dvb/dvb-usb/ec168.c | 18 +++++++++++++++--- > 1 files changed, 15 insertions(+), 3 deletions(-) > > diff --git a/drivers/media/dvb/dvb-usb/ec168.c b/drivers/media/dvb/dvb-usb/ec168.c > index 52f5d4f..1ba3e5d 100644 > --- a/drivers/media/dvb/dvb-usb/ec168.c > +++ b/drivers/media/dvb/dvb-usb/ec168.c > @@ -36,7 +36,9 @@ static int ec168_rw_udev(struct usb_device *udev, struct ec168_req *req) > int ret; > unsigned int pipe; > u8 request, requesttype; > - u8 buf[req->size]; > + u8 *buf; > + > + > > switch (req->cmd) { > case DOWNLOAD_FIRMWARE: > @@ -72,6 +74,12 @@ static int ec168_rw_udev(struct usb_device *udev, struct ec168_req *req) > goto error; > } > > + buf = kmalloc(req->size, GFP_KERNEL); > + if (!buf) { > + ret = -ENOMEM; > + goto error; > + } > + > if (requesttype == (USB_TYPE_VENDOR | USB_DIR_OUT)) { > /* write */ > memcpy(buf, req->data, req->size); > @@ -84,13 +92,13 @@ static int ec168_rw_udev(struct usb_device *udev, struct ec168_req *req) > msleep(1); /* avoid I2C errors */ > > ret = usb_control_msg(udev, pipe, request, requesttype, req->value, > - req->index, buf, sizeof(buf), EC168_USB_TIMEOUT); > + req->index, buf, req->size, EC168_USB_TIMEOUT); > > ec168_debug_dump(request, requesttype, req->value, req->index, buf, > req->size, deb_xfer); > > if (ret< 0) > - goto error; > + goto err_dealloc; > else > ret = 0; > > @@ -98,7 +106,11 @@ static int ec168_rw_udev(struct usb_device *udev, struct ec168_req *req) > if (!ret&& requesttype == (USB_TYPE_VENDOR | USB_DIR_IN)) > memcpy(req->data, buf, req->size); > > + kfree(buf); > return ret; > + > +err_dealloc: > + kfree(buf); > error: > deb_info("%s: failed:%d\n", __func__, ret); > return ret; -- http://palosaari.fi/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/