Re: [PATCH] genirq/msi: Make sure early activation of all PCI MSIs

From: Marc Zyngier <maz@kernel.org>
To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
Cc: linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, eric.auger@redhat.com,
	tglx@linutronix.de, linuxarm@openeuler.org,
	"Zengtao (B)" <prime.zeng@hisilicon.com>,
	"Wangzhou (B)" <wangzhou1@hisilicon.com>
Subject: Re: [PATCH] genirq/msi: Make sure early activation of all PCI MSIs
Date: Sat, 23 Jan 2021 12:32:53 +0000	[thread overview]
Message-ID: <f1aceff55b3580194b41b812ba7ffb76@kernel.org> (raw)
In-Reply-To: <c084871426cb4c9b9e0fe0684ca4c276@huawei.com>

Hi Shameer,

On 2021-01-22 09:21, Shameerali Kolothum Thodi wrote:
> Hi Marc,
> 

[...]

>> I find this pretty complicated, and the I'd like to avoid injecting 
>> the PCI
>> MSI-vs-MSI-X concept in something that is supposed to be bus-agnostic.
> 
> Agree. That’s mainly because I was very skeptical(TBH, very limited in
> my knowledge
> on this msi core code) about changing the MSI-X activation logic here
> and just thought
> of limiting the impact to MSI case as a first attempt.
> 
>> What's wrong with the following (untested) patch, which looks much 
>> simpler?
> 
> Yes, had tried this as one of the early fix, but as said above was not
> very sure of
> the impact on other platforms. Tested this again and it works.
> 
> Please send it.

Actually, there is a better way, which is to have a proper iterator on
vectors instead of descriptors. With that and a bit of cleanup, the
patch[1] looks pretty neat.

Please give it a go.

Thanks,

         M.

[1] https://lore.kernel.org/r/20210123122759.1781359-1-maz@kernel.org
-- 
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