Recursion in ACPI EC causes GPE lockup

[Hans Petter Selasky]

Hi,

I've managed to debug a problem in acpi_ec.c with a recent skylake laptop:

In EcSpaceHandler() there is a call to EcGpeQueryHandler(). This causes 
EcSpaceHandler() to recurse during cold boot.

When EcGpeQueryHandler() is recursing it appears that because the 
completion of a GPE interrupt also invokes EcSpaceHandler() again, we go 
into an infinite loop, and the ACPI just generate more and more commands 
that EcGpeQueryHandler() never completes, because it is reading the 
command queue first all the way.

Solution: Don't allow EcGpeQueryHandler() to recurse this way. The 
attached patch entirely fixes my problem.

Can someone here review the attached patch?

--HPS
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