From mboxrd@z Thu Jan 1 00:00:00 1970 From: k.kozlowski@samsung.com (Krzysztof Kozlowski) Date: Wed, 30 Sep 2015 16:37:41 +0900 Subject: [PATCH] ARM: exynos_defconfig: Enable WiFi-Ex as a module instead built-in In-Reply-To: <560B8DA3.6060507@osg.samsung.com> References: <1443530546-3066-1-git-send-email-javier@osg.samsung.com> <560B2EA4.8050406@samsung.com> <560B8DA3.6060507@osg.samsung.com> Message-ID: <560B9145.6070606@samsung.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.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