From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mout02.posteo.de ([185.67.36.66]:46442 "EHLO mout02.posteo.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751591AbcJEHkj (ORCPT ); Wed, 5 Oct 2016 03:40:39 -0400 Received: from submission (posteo.de [89.146.220.130]) by mout02.posteo.de (Postfix) with ESMTPS id A06AC209DD for ; Wed, 5 Oct 2016 09:40:37 +0200 (CEST) Date: Wed, 5 Oct 2016 09:40:36 +0200 From: Patrick Boettcher To: Jiri Kosina Cc: =?UTF-8?B?SsO2cmc=?= Otte , Linux Kernel Mailing List , Andy Lutomirski , Michael Krufky , Mauro Carvalho Chehab , linux-media@vger.kernel.org Subject: dvb-usb stack-memory used for URB-buffers (was: Re: Problem with VMAP_STACK=y) Message-ID: <20161005094036.3ffa11b5@vdr> In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-media-owner@vger.kernel.org List-ID: Hi, On Tue, 4 Oct 2016 15:26:28 +0200 (CEST) Jiri Kosina wrote: > On Tue, 4 Oct 2016, Jörg Otte wrote: > > > With kernel 4.8.0-01558-g21f54dd I get thousands of > > "dvb-usb: bulk message failed: -11 (1/0)" > > messages in the logs and the DVB adapter is not working. > > > > It tourned out the new config option VMAP_STACK=y (which is the > > default) is the culprit. > > No problems for me with VMAP_STACK=n. > > I'd guess that this is EAGAIN coming from usb_hcd_map_urb_for_dma() > as the DVB driver is trying to perform on-stack DMA. I really thought that this youngster-mistake of mien (these drivers+framework date from 2004-2006 and there it worked just fine) had been fixed some years ago. Seems not the be the case :-(. However, I'm happy to see people using these devices now. Even though I don't have them anymore (or never had them in the first place). Mauro, could you please bring me up to speed or remind when and where you did changes in this regard? I got a little bit rusty regarding linux-media, but I'd be happy to help. regards, -- Patrick.