Re: [PATCH 5/5] ARM: tegra: enable wireless in defconfig
From: Wei Ni <hidden>
Date: 2012-07-06 03:20:54
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linux-arm-kernel, lkml
On Fri, 2012-07-06 at 04:42 +0800, Stephen Warren wrote:
On 07/05/2012 02:35 PM, Marc Dietrich wrote:quoted
On Thursday 05 July 2012 13:59:11 Stephen Warren wrote:quoted
On 07/04/2012 03:34 AM, Wei Ni wrote:quoted
New options enabled: * WIRELESS: (dependency) * CFG80211: (dependency) * WLAN: (dependency) * BRCMFMAC: wlan driver, enable as module.diff --git a/arch/arm/configs/tegra_defconfigb/arch/arm/configs/tegra_defconfig +CONFIG_BRCMFMAC=mWhy does this need to be a module? Everything else in tegra_defconfig is built-in, and it'd be nice to be consistent here. Built-in makes net-booting new kernels from U-Boot much easier, since there aren't any modules to copy.network drivers (especially wifi) are often modules because they need firmwares.So I certainly see that WiFi modules may need firmware. But I don't see why that should imply they must be modules; they should be able to defer their firmware loading until the firmware is available.
The wifi driver will try to load the firmware form the filesystem in its initialization. In some board, the filesystem is on the SD/MMC card, and if the wifi card is initialized before that SD/MMC card, it can't read the filesystem and can't get the firmware, since the SD/MMC card doesn't be initialized yet. then the wifi driver's initialization will be failed. So the wifi driver are often built as modules.
quoted
I'm not sure if the kernel can compile them in every case. Our RT2x00 is an example (which also needs a defconfig entry btw) but brcmfmac also needs it as modinfo shows. Beside that, I don't think you want to netboot using wifi and u- boot because this needs a huge wireless framework which u-boot doesn't have.I net-boot using a USB wired Ethernet adapter. The issue isn't that I want to use wireless from U-Boot, but rather than it's easy to download the zImage and .dtb using U-Boot since they're just copied to RAM, but getting a bunch of modules into a filesystem on the target before booting the kernel is more painful. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html