[PATCH] powerpc/xive: discard ESB load value when interrupt is invalid

[Michael Ellerman]

Greg Kurz <groug at kaod.org> writes:
> On Tue, 14 Jan 2020 08:44:54 +0100
> Cédric Le Goater <clg at kaod.org> wrote:
>> On 1/14/20 2:14 AM, Michael Ellerman wrote:
>> > Cédric Le Goater <clg at kaod.org> writes:
>> >> On 1/13/20 2:01 PM, Cédric Le Goater wrote:
>> >>> From: Frederic Barrat <fbarrat at linux.ibm.com>
>> >>>
>> >>> A load on an ESB page returning all 1's means that the underlying
>> >>> device has invalidated the access to the PQ state of the interrupt
>> >>> through mmio. It may happen, for example when querying a PHB interrupt
>> >>> while the PHB is in an error state.
>> >>>
>> >>> In that case, we should consider the interrupt to be invalid when
>> >>> checking its state in the irq_get_irqchip_state() handler.
>> >>
>> >>
>> >> and we need also these tags :
>> >>
>> >> Fixes: da15c03b047d ("powerpc/xive: Implement get_irqchip_state method for XIVE to fix shutdown race")
>> >> Cc: stable at vger.kernel.org # v5.3+
>> > 
>> > I added those, although it's v5.4+, as the offending commit was first
>> > included in v5.4-rc1.
>> 
>> Ah yes. I mistook the merge tag of the branch used for the PR (v5.3-rc2)
>> 
>
> You might want to use 'git tag --contains':
>
> [greg at bahia kernel-linus]$ git tag --contains da15c03b047d
> for-linus
> kvm-5.4-2
> next-20191118
> next-20191126
> tags/kvm-5.4-1
> tags/kvm-5.4-2
> v5.4
> v5.4-rc1

Or:

  $ git describe --match "v[0-9]*" --contains da15c03b047d
  v5.4-rc1~99^2~134^2~17

cheers