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Date:   Tue, 25 Oct 2022 16:32:52 +0200
From:   Johan Hovold <johan@kernel.org>
To:     Sudeep Holla <sudeep.holla@arm.com>
Cc:     Johan Hovold <johan+linaro@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Lorenzo Pieralisi <lpieralisi@kernel.org>,
        Ulf Hansson <ulf.hansson@linaro.org>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] firmware/psci: demote suspend-mode warning to debug level
Message-ID: <Y1fzlItO+cwVybZm@hovoldconsulting.com>
References: <20221024143417.11463-1-johan+linaro@kernel.org>
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On Tue, Oct 25, 2022 at 02:26:55PM +0100, Sudeep Holla wrote:
> On Tue, Oct 25, 2022 at 02:56:00PM +0200, Johan Hovold wrote:
> > On Tue, Oct 25, 2022 at 12:53:55PM +0100, Sudeep Holla wrote:
> > > On Mon, Oct 24, 2022 at 04:34:17PM +0200, Johan Hovold wrote:
> > > > On some Qualcomm platform, like SC8280XP, the attempt to set PC mode
> > > > during boot fails with PSCI_RET_DENIED and since commit 998fcd001feb
> > > > ("firmware/psci: Print a warning if PSCI doesn't accept PC mode") this
> > > > is now logged at warning level:
> > > >
> > > > 	psci: failed to set PC mode: -3
> > > >
> > > > As there is nothing users can do about the firmware behaving this way,
> > > > demote the warning to debug level.
> > > >
> > >
> > > As mentioned in the other thread I prefer to keep this as error as we
> > > shouldn't mask this error and enable more/newer platforms to ignore it
> > > when they can go and fix it. So I don't agree with this.
> >
> > But now every owner of an X13s laptop will see this not very informative
> > error at every boot and wonder what it means. Has something gone broken?
> > Should they be worried? Can something be done about it?
> >
> 
> I understand that but I have expressed why I am concerned on generalising
> it. As long as we inform the concerned owners running Linux(which is quite
> small at the moment), keeping it will help to get these fixed on platforms
> that are running Linux today for validation and get it fixed if their
> platform firmware suffers from the same.

Trying to inform every user that a warning during boot is actually
benign and nothing to worry about generally seems backwards to me and is
not something that is likely to scale.

> > Remember that this is firmware used by Windows machines so by the time
> > we see this in Linux it's probably way too late to fix in firmware
> > anyway.
> >
> 
> I am well aware of that fact, but I am targeting platforms that are using
> Linux for validation today.
> 
> Honestly, I am not sure if we need to target for zero errors or warnings
> on the platforms instead of repeatedly annoy them with warnings until it
> is fixed. Otherwise I see it won't be fixed ever.

I understand the sentiment, but will having this warning there actually
lead to any firmware changes? Or will it just lead to having developers
and users debug and report issues which cannot be fixed?

And surely there must be better ways to check firmware for compliance
than scanning Linux boot logs for warnings?

Johan