Re: [PATCH 5/5] ARM: tegra: enable wireless in defconfig

[Stephen Warren <swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>]

On 07/05/2012 02:35 PM, Marc Dietrich wrote:
> On Thursday 05 July 2012 13:59:11 Stephen Warren wrote:
>> On 07/04/2012 03:34 AM, Wei Ni wrote:
>>> New options enabled:
>>> * WIRELESS: (dependency)
>>> * CFG80211: (dependency)
>>> * WLAN: (dependency)
>>> * BRCMFMAC: wlan driver, enable as module.
>>>
>>> diff --git a/arch/arm/configs/tegra_defconfig
>>> b/arch/arm/configs/tegra_defconfig
>>>
>>> +CONFIG_BRCMFMAC=m
>>
>> Why 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.

> 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.