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From: yingjoe.chen@mediatek.com (Yingjoe Chen)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v5] clocksource: arch_timer: Fix code to use physical timers when requested
Date: Wed, 10 Dec 2014 17:19:26 +0800	[thread overview]
Message-ID: <1418203166.21309.3.camel@mtksdaap41> (raw)
In-Reply-To: <20141209165807.GJ31129@e104818-lin.cambridge.arm.com>

On Tue, 2014-12-09 at 16:58 +0000, Catalin Marinas wrote:
<...>
> You mix timer and counter terms here. Anyway, of we use physical timer,
> you could argue that it makes sense to use the corresponding physical
> counter (CNTPCT). However, on arm64 we only expose CNTVCT to user VDSO
> and we want to use the same in the kernel. When booting at EL2, CNTVCT
> == CNTPCT because we control CNTVOFF, that's unless we have some broken
> firmware that does not restore CNTVOFF correctly. That's what we want
> to spot early, hence the aim to always use the virtual counter (but not
> the timer, use use the physical timer as it makes it easier for KVM).
> 
> So the patch below, on top of linux-next, should solve the BUG():

Thanks for detail explanation and the patch. I tested it on my platform
and it did solve the issue. So,

Tested-by: Yingjoe Chen <yingjoe.chen@mediatek.com>

Joe.C

WARNING: multiple messages have this Message-ID (diff)
From: Yingjoe Chen <yingjoe.chen@mediatek.com>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: "Marc Zyngier" <Marc.Zyngier@arm.com>,
	"Sonny Rao" <sonnyrao@chromium.org>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>,
	"Mark Rutland" <Mark.Rutland@arm.com>,
	"Lorenzo Pieralisi" <Lorenzo.Pieralisi@arm.com>,
	"Russell King" <linux@arm.linux.org.uk>,
	"Sudeep Holla" <Sudeep.Holla@arm.com>,
	"Daniel Lezcano" <daniel.lezcano@linaro.org>,
	"Will Deacon" <Will.Deacon@arm.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"stable@vger.kernel.org" <stable@vger.kernel.org>,
	"dianders@chromium.org" <dianders@chromium.org>,
	"Olof Johansson" <olof@lixom.net>,
	"Thomas Gleixner" <tglx@linutronix.de>,
	"Stephen Boyd" <sboyd@codeaurora.org>,
	"Eddie Huang (黃智傑)" <eddie.huang@mediatek.com>,
	"Liviu Dudau" <Liviu.Dudau@arm.com>
Subject: Re: [PATCH v5] clocksource: arch_timer: Fix code to use physical timers when requested
Date: Wed, 10 Dec 2014 17:19:26 +0800	[thread overview]
Message-ID: <1418203166.21309.3.camel@mtksdaap41> (raw)
In-Reply-To: <20141209165807.GJ31129@e104818-lin.cambridge.arm.com>

On Tue, 2014-12-09 at 16:58 +0000, Catalin Marinas wrote:
<...>
> You mix timer and counter terms here. Anyway, of we use physical timer,
> you could argue that it makes sense to use the corresponding physical
> counter (CNTPCT). However, on arm64 we only expose CNTVCT to user VDSO
> and we want to use the same in the kernel. When booting at EL2, CNTVCT
> == CNTPCT because we control CNTVOFF, that's unless we have some broken
> firmware that does not restore CNTVOFF correctly. That's what we want
> to spot early, hence the aim to always use the virtual counter (but not
> the timer, use use the physical timer as it makes it easier for KVM).
> 
> So the patch below, on top of linux-next, should solve the BUG():

Thanks for detail explanation and the patch. I tested it on my platform
and it did solve the issue. So,

Tested-by: Yingjoe Chen <yingjoe.chen@mediatek.com>

Joe.C



  reply	other threads:[~2014-12-10  9:19 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-24  7:02 [PATCH v5] clocksource: arch_timer: Fix code to use physical timers when requested Sonny Rao
2014-11-24  7:02 ` Sonny Rao
2014-11-24  9:01 ` Daniel Lezcano
2014-11-24  9:01   ` Daniel Lezcano
2014-11-24 14:16   ` Catalin Marinas
2014-11-24 14:16     ` Catalin Marinas
2014-11-24 14:19     ` Daniel Lezcano
2014-11-24 14:19       ` Daniel Lezcano
2014-11-26 12:47 ` Daniel Lezcano
2014-11-26 12:47   ` Daniel Lezcano
2014-12-05  7:30 ` Olof Johansson
2014-12-05  7:30   ` Olof Johansson
2014-12-05 10:41 ` Yingjoe Chen
2014-12-05 10:41   ` Yingjoe Chen
2014-12-08 16:21   ` Catalin Marinas
2014-12-08 16:21     ` Catalin Marinas
2014-12-09  6:31     ` Yingjoe Chen
2014-12-09  6:31       ` Yingjoe Chen
2014-12-09 16:58       ` Catalin Marinas
2014-12-09 16:58         ` Catalin Marinas
2014-12-10  9:19         ` Yingjoe Chen [this message]
2014-12-10  9:19           ` Yingjoe Chen

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