From: Marc Zyngier <firstname.lastname@example.org> To: Jianyong Wu <email@example.com> Cc: firstname.lastname@example.org, email@example.com, firstname.lastname@example.org, email@example.com, firstname.lastname@example.org, email@example.com, firstname.lastname@example.org, email@example.com Subject: Re: [PATCH] doc/arm: take care restore order of GICR_* in ITS restore Date: Wed, 21 Jul 2021 10:53:37 +0100 [thread overview] Message-ID: <firstname.lastname@example.org> (raw) In-Reply-To: <email@example.com> On Wed, 21 Jul 2021 10:20:19 +0100, Jianyong Wu <firstname.lastname@example.org> wrote: > > When restore GIC/ITS, GICR_CTLR must be restored after GICR_PROPBASER > and GICR_PENDBASER. That is important, as both of GICR_PROPBASER and > GICR_PENDBASER will fail to be loaded when lpi has enabled yet in > GICR_CTLR. Keep the restore order above will avoid that issue. > Shout it out at the doc is very helpful that may avoid lots of debug work. But that's something that is already mandated by the architecture, isn't it? See "5.1 LPIs" in the architecture spec: <quote> If GICR_PROPBASER is updated when GICR_CTLR.EnableLPIs == 1, the effects are UNPREDICTABLE. [...] If GICR_PENDBASER is updated when GICR_CTLR.EnableLPIs == 1, the effects are UNPREDICTABLE. </quote> The point of this documentation is to make it explicit what is *not* covered by the architecture. Anything that is in the architecture still applies, and shouldn't be overlooked. Thanks, M. -- Without deviation from the norm, progress is not possible.
next prev parent reply other threads:[~2021-07-21 10:10 UTC|newest] Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-07-21 9:20 Jianyong Wu 2021-07-21 9:53 ` Marc Zyngier [this message] 2021-07-22 2:49 ` Jianyong Wu 2021-07-22 8:11 ` Marc Zyngier 2021-07-23 5:27 ` Jianyong Wu
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