[PATCH] b43: ensure ext PA lines are enabled for BCM4331

[Hauke Mehrtens]

On 06/01/2012 12:06 AM, Seth Forshee wrote:
> On Thu, May 31, 2012 at 06:23:25PM +0200, Hauke Mehrtens wrote:
>> On 05/31/2012 04:26 PM, Seth Forshee wrote:
>>> On Thu, May 31, 2012 at 04:16:05PM +0200, Hauke Mehrtens wrote:
>>>> Hi Seth,
>>>>
>>>> why don't you call this from bcma_pmu_workarounds() in
>>>> drivers/bcma/driver_chipcommon_pmu.c instead of calling this from b43? I
>>>> think it looks better to call some workarounds on chip common from bcma
>>>> and not from b43.
>>>
>>> Arend recommended calling it from within b43's start op, but I'm not
>>> sure of the reason. Arend?
>>>
>>> Agreed though that if there's no need to run it every time the interface
>>> is started then bcma_pmu_workarounds() would be a nicer place for it.
>>
>> brcmsmac calls the chip specific the workarounds in ai_doattach(), but
>> the ones for BCM4313 and BCM43224 are also in bcma_pmu_workarounds(),
>> this should be cleaned up to have them just at one place. In some old
>> version of brcmsmac the workaround for the BCM4331 was also called from
>> ai_doattach() function, but later removed likely because this devices is
>> not supported by brcmsmac.
>> So if there is not better reason as, the proprietary Broadcom driver
>> does so, I would like to see this call in bcma_pmu_workarounds().
> 
> I found the SDK code from a router source package, and oddly that code
> is clearing those bits in si_doattach(). In fact si_chipcontrl_epa4331()
> is never called to enable the ext PA lines, only to disable them. The
> sprom code reads the value before disabling them and restores it after
> reading from the sprom. Enabling the ext PA pins is what fixes things
> for me. Predictably, duplicating this in bcma makes wireless broken all
> the time.

The open source SDK just contains some of the code, the wireless part is
closed source and I haven't seen any call which enables this in the open
part too. The initial commit of brcm80211 to the kernel staging area
contains a call to this function with true given.
It is commit a9533e7ea3c410fed2f4cd8b3e1e213e48529b75 if you are interested.

> At any rate, it sounds like we're agreed to add the workaround in
> bcma_pmu_workarounds(), so I'll redo the patch.
> 
>>>> According to some Broadcom code this should also be called for chip_id
>>>> 43431 when turning it on and in the sprom code.
>>>
>>> I'm having trouble parsing this, specifically the "and in the sprom
>>> code" part. Can you clarify?
>>
>> In the Broadcom SDK code si_chipcontrl_epa4331(), the same function as
>> bcma_chipco_bcm4331_ext_pa_lines_ctl() in bcma, gets called for devices
>> with a chip id of 0x4331 and 43431, both seam to be BCM4331 devices. We
>> should also call our workarounds for both chip ids.
> 
> I'll fix this too.
> 
> Thanks,
> Seth
>