Message-ID: <1436610757.17661.1.camel@mtksdaap41>
Subject: Re: [PATCH v2 4/9] clocksource: mediatek: Use GPT as sched clock
 source
From: Yingjoe Chen <yingjoe.chen@mediatek.com>
To: Matthias Brugger <matthias.bgg@gmail.com>
CC: Daniel Kurtz <djkurtz@chromium.org>, Mark Rutland <mark.rutland@arm.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Russell King <linux@arm.linux.org.uk>, Arnd Bergmann <arnd@arndb.de>,
        Olof Johansson <olof@lixom.net>,
        "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
        Stephen Boyd <sboyd@codeaurora.org>, "Pawel Moll" <pawel.moll@arm.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Marc Carino <marc.ceeeee@gmail.com>,
        "Rob Herring" <robh+dt@kernel.org>,
        <linux-mediatek@lists.infradead.org>,
        "Sascha Hauer" <kernel@pengutronix.de>,
        srv_heupstream <srv_heupstream@mediatek.com>,
        "linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>
Date: Sat, 11 Jul 2015 18:32:37 +0800
In-Reply-To: <1551938.VHQvCCENeg@ubix>
References: <1431763110-443-1-git-send-email-yingjoe.chen@mediatek.com>
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On Fri, 2015-07-03 at 17:51 +0200, Matthias Brugger wrote:
> On Friday, July 03, 2015 09:48:42 PM Daniel Kurtz wrote:

<...>

> > >> @@ -243,6 +251,8 @@ static void __init mtk_timer_init(struct device_node
> > >> *node)>> 
> > >>         mtk_timer_setup(evt, GPT_CLK_SRC, TIMER_CTRL_OP_FREERUN, 1);
> > >>         clocksource_mmio_init(evt->gpt_base + TIMER_CNT_REG(GPT_CLK_SRC),
> > >>         
> > >>                         node->name, rate, 300, 32,
> > >>                         clocksource_mmio_readl_up);
> > >> 
> > >> +       gpt_base = evt->gpt_base;
> > > 
> > > This is really hacky. We should clean up the code and provide
> > > mtk_clock_event_device globally.
> > > Please add the patch below, which does exactly this.
> > 
> > I don't think this is so hacky.
> > In light of Stephen's comment about the benefit of using
> > container_of() to extract gpt_base from the passed in struct
> > clock_event_device in the other routines, what is the benefit of
> > making more of mtk_clock_event_device global?
> > I think what Yingjoe has implemented is short and sweet.
> > 
> 
> Huh, this patch got somehow forgotten.
> Ok, just one comment. I would prefer to rename the global gpt_base to 
> gpt_sched_base or something similar and set the pointer + offset directly 
> mtk_timer_init.


In next version, I will it change to:

static void __iomem *gpt_sched_reg __read_mostly;

and in mtk_timer_init:

+       gpt_sched_reg = evt->gpt_base + TIMER_CNT_REG(GPT_CLK_SRC);

Joe.C


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