Re: brcmsmac in kernel driver on a Samsung NC110

["Arend van Spriel" <arend@broadcom.com>]

On 03/27/2013 01:21 PM, John Talbut wrote:
> 
> 
> On 27/03/13 12:06, Arend van Spriel wrote:
>> On 03/27/2013 12:22 PM, Arend van Spriel wrote:
>>> On 03/27/2013 11:45 AM, John Talbut wrote:
>>>>
>>>>
>>>> On 27/03/13 10:33, Rafał Miłecki wrote:
>>>>> 2013/3/27 John Talbut <jt@dpets.co.uk>:
>>>>>> On 27/03/13 07:46, Rafał Miłecki wrote:
>>>>>>> 2013/3/26 Arend van Spriel <arend@broadcom.com>:
>>>>>>>> On 03/26/2013 08:48 PM, John Talbut wrote:
>>>>>>>>> echo "14e4 4357" > /sys/bus/pci/drivers/bcma-pci-bridge/new_id
>>>>>>>>> bash: /sys/bus/pci/drivers/bcma-pci-bridge/new_id: No such file or directory
>>>>>>>>
>>>>>>>> This could mean you do not have CONFIG_BCMA_HOST_PCI=y in your .config
>>>>>>>
>>>>>>> Exactly. Make sure you have CONFIG_BCMA_HOST_PCI=y and that your
>>>>>>> host_pci.c is not modified/hacked/whatever.
>>>>>>>
>>>>>>> You can compare it with
>>>>>>> http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/bcma/host_pci.c
>>>>>>> bcma_pci_bridge_tbl.
>>>>>>>
>>>>>> OK, thanks, I have recompiled the kernel with CONFIG_BCMA_HOST_PCI=y and
>>>>>> we have some progress.
>>>>>>
>>>>>> ls /sys/bus/bcma/devices
>>>>>> bcma0:0
>>>>>>
>>>>>> lspci -d 14e4: -v
>>>>>> now has a line:
>>>>>> Kernel driver in use: bcma-pci-bridge
>>>>>>
>>>>>> host_pci.c is the same as torvalds.
>>>>>>
>>>>>> However, kernel log includes:
>>>>>> brcmsmac bcma0:0: firmware: agent aborted loading brcm/bcm43xx-0.fw (not
>>>>>> found?)
>>>>>> ieee80211 phy0: brcmsmac: Failed to find firmware usually in
>>>>>> /lib/firmware/brcm
>>>>>> brcmsmac: brcms_bcma_probe: brcms_attach failed!
>>>>>
>>>>> "Failed to find firmware". You didn't tell us if you have firmware installed.
>>>>> ls /lib/firmware/brcm/
>>>>> http://wireless.kernel.org/en/users/Drivers/brcm80211#Firmware_installation
>>>>>
>>>> Sorry, meant to do that:
>>>> ls /lib/firmware/brcm/
>>>> bcm43xx-0.fw bcm43xx_hdr-0.fw
>>>>
>>
>> To confirm my suspicion could you try following (as root):
>>
>> /sys/bus/bcma/drivers/brcmsmac # echo bcma0:0 > bind
>>
>> This should retrigger brcmsmac to get firmware and use the device.
>>
>> Regards,
>> Arend
> 
> Yes.
> cd /sys/bus/bcma/drivers/brcmsmac
> echo bcma0:0 > bind
> 
> And I now have wlan0.
> 
> So, how to get the firmware loaded after the root filesystem is mounted?

You just did. I admit this is a bit tricky way to do it. The driver
would need to be reworked to defer firmware loading, but there is not
clear API. I believe the general recommendation is to attempt firmware
loading upon IFFUP, because you can assume the actual root filesystem is
mounted upon receiving that notification. Let me try to come up with a
patch.

Regards,
Arend