Re: [PATCH] ARM: BCM5301X: Add back handler ignoring external imprecise aborts

[Florian Fainelli <f.fainelli@gmail.com>]

On 10/31/2016 01:59 PM, Hauke Mehrtens wrote:
> 
> 
> On 10/31/2016 07:08 PM, Scott Branden wrote:
>> Hi Rafal,
>>
>>
>> On 16-10-29 04:12 AM, Rafał Miłecki wrote:
>>> From: Rafał Miłecki <rafal@milecki.pl>
>>>
>>> Since early BCM5301X days we got abort handler that was removed by
>>> commit 937b12306ea79 ("ARM: BCM5301X: remove workaround imprecise abort
>>> fault handler"). It assumed we need to deal only with pending aborts
>>> left by the bootloader. Unfortunately this isn't true for BCM5301X.
>>>
>>> When probing PCI config space (device enumeration) it is expected to
>>> have master aborts on the PCI bus. Most bridges don't forward (or they
>>> allow disabling it) these errors onto the AXI/AMBA bus but not the
>>> Northstar (BCM5301X) one.
>> Should we only add this workaround code if CONFIG_PCI is on then?
> 
> I think all the supported northstar devices have a PCIe controller. We
> could add such a CONFIG_PCI check, but I do not see a big advantage.

Actually, I do see a couple disadvantages if we gate this with
CONFIG_PCI: if this problem shows up irrespective of your kernel
configuration, you want the error handler to clear it, not rely on
CONFIG_PCI to be enabled for the error to go away and also, without an
additional ifdef, additional compiler coverage.
-- 
Florian