Re: v4.14 fix for Hikey 960 unbalanced IRQ enablement

Rafael David Tinoco
2018-12-03T18:24:48Z

>> Greg,
>>
>> Patch 5 in this series seems to explain the best what is happening here:
>>
>>> With the following changes, we fix all in one:
>>>
>>> - Do the setup, one time, at probe time
>>>
>>> - Add the IRQF_ONESHOT, ack the interrupt in the threaded handler
>>>
>>> - Remove the interrupt handler
>>>
>>> - Set the correct value for the LAG register
>>>
>>> - Remove all the irq_enabled stuff in the code as the interruption
>>> handling is fixed
>>>
>>> - Remove the 3ms delay
>>>
>>> - Reorder the initialization routine to be in the right order
>>
>> We can't revert anything because the breakage was there since the driver
>> was introduced.
>
> So the driver was broken in 4.14, why not just use 4.19 instead? This
> isn't a 4.14 regression, it's something that obviously no one has
> noticed for a year now, so why backport these big patches to 4.14 now?
>
> thanks,
>
> greg k-h
>

This was caught during our functional tests. No direct complains, but,
since it included a trace, and there was a fix for it, I thought it
could be accepted for upstream v4.14 (it is included in other v4.14
kernels, like Android's).

thanks!
--
Rafael D. Tinoco
Linaro - Kernel Validation