From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754681AbbI3Hhw (ORCPT ); Wed, 30 Sep 2015 03:37:52 -0400 Received: from mailout1.w1.samsung.com ([210.118.77.11]:9209 "EHLO mailout1.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753907AbbI3Hhu (ORCPT ); Wed, 30 Sep 2015 03:37:50 -0400 X-AuditID: cbfec7f4-f79c56d0000012ee-13-560b914beca3 Subject: Re: [PATCH] ARM: exynos_defconfig: Enable WiFi-Ex as a module instead built-in To: Javier Martinez Canillas , linux-kernel@vger.kernel.org References: <1443530546-3066-1-git-send-email-javier@osg.samsung.com> <560B2EA4.8050406@samsung.com> <560B8DA3.6060507@osg.samsung.com> Cc: Mauro Carvalho Chehab , Kukjin Kim , Thierry Reding , Anand Moon , Russell King , linux-samsung-soc@vger.kernel.org, Andreas Faerber , Lukasz Majewski , linux-arm-kernel@lists.infradead.org From: Krzysztof Kozlowski Message-id: <560B9145.6070606@samsung.com> Date: Wed, 30 Sep 2015 16:37:41 +0900 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-version: 1.0 In-reply-to: <560B8DA3.6060507@osg.samsung.com> Content-type: text/plain; charset=windows-1252 Content-transfer-encoding: 7bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFmpkkeLIzCtJLcpLzFFi42I5/e/4NV3vidxhBkcWGlk0byq2ePN2DZPF 6xeGFv2PXzNbvHm4mdFi0+NrrBaXd81hs5hxfh+TxbqNt9gtbl/mtVj9rMLi9m8+Bx6PluYe No+ds+6ye2xa1cnmsXlJvUdv8zs2jy39QKG+LasYPTafrvb4vEkugDOKyyYlNSezLLVI3y6B K2PWlTWsBY8FKuZuXMzawLiJt4uRg0NCwERi/e+SLkZOIFNM4sK99WxdjFwcQgJLGSU+z1nH BOF8YZRo2TqbHaRKWCBSYvuj42wgtohAqMS/i7cZIYo6GSW2HJ4O5jALPGSSeHjuDxNIFZuA scTm5UvAOngFtCSaes6DxVkEVCXOLmhjBLFFBSIkTp19C1UjKPFj8j0WEJtTQF/izbsmNpBT mQX0JO5f1AIJMwvIS2xe85Z5AqPALCQdsxCqZiGpWsDIvIpRNLU0uaA4KT3XUK84Mbe4NC9d Lzk/dxMjJGK+7GBcfMzqEKMAB6MSD+8LAe4wIdbEsuLK3EOMEhzMSiK8L/uBQrwpiZVVqUX5 8UWlOanFhxilOViUxHnn7nofIiSQnliSmp2aWpBaBJNl4uCUamC0PFa0VEPYkCOUw443WkXk VTrr/4rsM3x1KaZrIj5XpRXs6WTMLLBikS7avlRjT+YyVd0TIvuvb98kPqdJNqx5icDD4uwH 5vochzyaHs5Z/dj/iOizC8nx30S/RhdcvDbvaNTUyONPV58z3tGX897z8L+/CtXzuBf4Lpum 6mMbN/0GC6PwFmslluKMREMt5qLiRABJxWLxlAIAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 30.09.2015 16:22, Javier Martinez Canillas wrote: > Hello Krzysztof, > > On 09/30/2015 02:36 AM, Krzysztof Kozlowski wrote: >> On 29.09.2015 21:42, Javier Martinez Canillas wrote: >>> The Marvell WiFi-Ex driver tries to load a firmware on probe. So if the >>> driver is built-in and probed before a firmware is available, this is >>> not loaded and the chip does not work. >>> >>> This happens for example if an initramfs isn't used since the driver is >>> probed before the root filesystem is mounted. >>> >>> Change the default config since the driver isn't needed for machines to >>> boot and is more convenient to have it enabled as a module to avoid >>> requiring an initramfs or to have the firmware built into the kernel. >>> >>> Signed-off-by: Javier Martinez Canillas >>> >>> --- >>> >>> arch/arm/configs/exynos_defconfig | 4 ++-- >>> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> The user-space can always initiate re-probing of device - just re-bind > > It is true that you can force a re-probing from user-space by doing: > > $ echo "mmc2:0001:1" > /sys/bus/sdio/drivers/mwifiex_sdio/unbind > $ echo "mmc2:0001:1" > /sys/bus/sdio/drivers/mwifiex_sdio/bind I suppose the unbind won't be needed, because device aborted the probe... so only one another bind. > > but: > > a) This is not obvious. In fact, I didn't think that possibility > before you mentioned and I've been using Linux for many years :) Eh, questionable. Obvious for me :) > > b) This is not something that isn't done automatically by init systems. Right. > > So what users will see is that the driver was probed successfully but > the firmware fails to load later (since the driver users the async > request_firmware_nowait function to request the firmware). Okay. > >> it. However I assume that driver cannot work without firmware? >> > > Yes, it doesn't. I explained this in the commit message. Do you > think it should be made more clear? No, its OK, I agree. Reviewed-by: Krzysztof Kozlowski Best regards, Krzysztof