From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from smtp2-g21.free.fr ([212.27.42.2]:45725 "EHLO smtp2-g21.free.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751294AbbL1KoI (ORCPT ); Mon, 28 Dec 2015 05:44:08 -0500 Subject: Re: Automatic device driver back-porting with media_build To: linux-media Cc: Mauro Carvalho Chehab , Hans Verkuil References: <5672A6F0.6070003@free.fr> <20151217105543.13599560@recife.lan> From: Mason Message-ID: <56811270.7070907@free.fr> Date: Mon, 28 Dec 2015 11:44:00 +0100 MIME-Version: 1.0 In-Reply-To: <20151217105543.13599560@recife.lan> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Hello Mauro, Haven't heard back from you in a while. Maybe someone else can point out what I'm doing wrong? On 17/12/2015 13:55, Mauro Carvalho Chehab wrote: > Mason wrote: > >> I have a TechnoTrend TT-TVStick CT2-4400v2 USB tuner, as described here: >> http://linuxtv.org/wiki/index.php/TechnoTrend_TT-TVStick_CT2-4400 >> >> According to the article, the device is supported since kernel 3.19 >> and indeed, if I use a 4.1 kernel, I can pick CONFIG_DVB_USB_DVBSKY >> and everything seems to work. >> >> Unfortunately (for me), I've been asked to make this driver work on >> an ancient 3.4 kernel. > > The goal is to allow compilation since 2.6.32, but please notice that > not all drivers will go that far. Basically, when the backport seems too > complex, we just remove the driver from the list of drivers that are > compiled for a given legacy version. > > See the file v4l/versions.txt to double-check if the drivers you need > have such restrictions. I suspect that, in the specific case of > DVB_USB_DVBSKY, it should compile. Whatever options I pick for my 3.4 config, CONFIG_DVB_USB_DVBSKY remains unset in v4l/.config $ grep -r DVB_USB_DVBSKY media_build/v4l/ media_build/v4l/Kconfig:config DVB_USB_DVBSKY media_build/v4l/Kconfig.kern: [snip config USB] media_build/v4l/Kconfig.kern: [snip config I2C] media_build/v4l/.myconfig:CONFIG_DVB_USB_DVBSKY := n media_build/v4l/Makefile.media:obj-$(CONFIG_DVB_USB_DVBSKY) += dvb-usb-dvbsky.o media_build/v4l/.config:# CONFIG_DVB_USB_DVBSKY is not set I suppose some prerequisite is missing? Does anything obvious come to mind? I've resorted to interrupting the build and changing v4l/.config to CONFIG_DVB_USB_DVBSKY=m (and the module is correctly built) but this feels like an unnecessary hack. Regards.