From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from ec2-52-27-115-49.us-west-2.compute.amazonaws.com ([52.27.115.49]:41423 "EHLO osg.samsung.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753598AbdBNTqF (ORCPT ); Tue, 14 Feb 2017 14:46:05 -0500 Date: Tue, 14 Feb 2017 17:45:57 -0200 From: Mauro Carvalho Chehab To: Greg KH Cc: Linux Media Mailing List , Mauro Carvalho Chehab , Mauro Carvalho Chehab , stable@vger.kernel.org Subject: Re: [PATCH] siano: make it work again with CONFIG_VMAP_STACK Message-ID: <20170214174557.4d7b2100@vento.lan> In-Reply-To: <20170214194146.GA28566@kroah.com> References: <08f1b470a156163cc3394f73bcbaea3925b6f376.1487100723.git.mchehab@s-opensource.com> <20170214194146.GA28566@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Em Tue, 14 Feb 2017 11:41:46 -0800 Greg KH escreveu: > On Tue, Feb 14, 2017 at 05:32:11PM -0200, Mauro Carvalho Chehab wrote: > > Reported as a Kaffeine bug: > > https://bugs.kde.org/show_bug.cgi?id=375811 > > > > 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. > > > > On Kernel 4.9, the default is to not accept DMA on stack anymore. > > > > Tested with USB ID 2040:5510: Hauppauge Windham > > > > Cc: stable@vger.kernel.org # For 4.9+ > > Unless there is some major reason, this should go into _all_ stable > releases, as the driver would be broken on them all for platforms that > can't handle USB data that is not DMA-able. This has been a requirement > for USB drivers since the 2.2 days. Good point! No, there's no particular reason why not backporting it to older Kernel releases. I suspect that this particular part of the driver hasn't changed for a while. So, it can very likely be backported to all stable releases. I'll fix the C/C message when submitting it upstream. Thanks, Mauro