From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754570AbcJEQpI (ORCPT ); Wed, 5 Oct 2016 12:45:08 -0400 Received: from mail-ua0-f177.google.com ([209.85.217.177]:35517 "EHLO mail-ua0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751288AbcJEQpG (ORCPT ); Wed, 5 Oct 2016 12:45:06 -0400 MIME-Version: 1.0 In-Reply-To: References: <20161005093417.6e82bd97@vdr> <20161005060450.1b0f2152@vento.lan> From: =?UTF-8?Q?J=C3=B6rg_Otte?= Date: Wed, 5 Oct 2016 18:45:05 +0200 Message-ID: Subject: Re: Problem with VMAP_STACK=y To: Andy Lutomirski Cc: Mauro Carvalho Chehab , Jiri Kosina , Patrick Boettcher , Linux Kernel Mailing List , Andy Lutomirski , Michael Krufky , Mauro Carvalho Chehab , Linux Media Mailing List Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by mail.home.local id u95GjHEJ013699 2016-10-05 17:53 GMT+02:00 Andy Lutomirski : > On Wed, Oct 5, 2016 at 8:21 AM, Jörg Otte wrote: >> 2016-10-05 11:04 GMT+02:00 Mauro Carvalho Chehab : >>> Em Wed, 5 Oct 2016 09:50:42 +0200 (CEST) >>> Jiri Kosina escreveu: >>> >>>> On Wed, 5 Oct 2016, Patrick Boettcher wrote: >>>> >>>> > > > Thanks for the quick response. >>>> > > > Drivers are: >>>> > > > dvb_core, dvb_usb, dbv_usb_cynergyT2 >>>> > > >>>> > > This dbv_usb_cynergyT2 is not from Linus' tree, is it? I don't seem >>>> > > to be able to find it, and the only google hit I am getting is your >>>> > > very mail to LKML :) >>>> > >>>> > It's a typo, it should say dvb_usb_cinergyT2. >>>> >>>> Ah, thanks. Same issues there in >>>> >>>> cinergyt2_frontend_attach() >>>> cinergyt2_rc_query() >>>> >>>> I think this would require more in-depth review of all the media drivers >>>> and having all this fixed for 4.9. It should be pretty straightforward; >>>> all the instances I've seen so far should be just straightforward >>>> conversion to kmalloc() + kfree(), as the buffer is not being embedded in >>>> any structure etc. >>> >>> What we're doing on most cases is to put a buffer (usually with 80 >>> chars for USB drivers) inside the "state" struct (on DVB drivers), >>> in order to avoid doing kmalloc/kfree all the times. One such patch is >>> changeset c4a98793a63c4. >>> >>> I'm enclosing a non-tested patch fixing it for the cinergyT2-core.c >>> driver. >>> >>> Thanks, >>> Mauro >>> >>> [PATCH] cinergyT2-core: don't do DMA on stack >>> >> >> Tried the cinergyT2 patch. No success. When I select a TV channel >> just nothing happens. There are no error messages. > > Could you try compiling with CONFIG_DEBUG_VIRTUAL=y and seeing if you > get a nice error message? > > --Andy Done. Still no error messages in dmesg and syslog. DVB adapter signals it is tuned to the channel. For me it looks like there`s no data reaching the application (similar to if I forget to connect an antenna). Jörg