From mboxrd@z Thu Jan  1 00:00:00 1970
From: Arnd Bergmann <arnd@arndb.de>
Subject: Re: [PATCH v3 02/10] clocksource:arm_global_timer: Add ARM global timer support.
Date: Thu, 20 Jun 2013 21:02:30 +0200
Message-ID: <201306202102.30478.arnd@arndb.de>
References: <1371736996-8770-1-git-send-email-srinivas.kandagatla@st.com> <1371737121-9295-1-git-send-email-srinivas.kandagatla@st.com>
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To: Srinivas KANDAGATLA <srinivas.kandagatla@st.com>
Cc: linux-arm-kernel@lists.infradead.org, Rob Landley <rob@landley.net>, Grant Likely <grant.likely@linaro.org>, Rob Herring <rob.herring@calxeda.com>, Russell King <linux@arm.linux.org.uk>, Stuart Menefy <stuart.menefy@st.com>, John Stultz <john.stultz@linaro.org>, Thomas Gleixner <tglx@linutronix.de>, Linus Walleij <linus.walleij@linaro.org>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Jiri Slaby <jslaby@suse.cz>, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree-discuss@lists.ozlabs.org, kernel@stlinux.com, linux-serial@vger.kernel.org, Mark Brown <broonie@kernel.org>, Stephen Gallimore <stephen.gallimore@st.com>, Rob Herring <robherring2@gmail.com>, Will Deacon <will.deacon@arm.com>

On Thursday 20 June 2013, Srinivas KANDAGATLA wrote:
> +static u64 gt_counter_read(void)
> +{
> +       u64 counter;
> +       u32 lower;
> +       u32 upper, old_upper;
> +
> +       upper = __raw_readl(gt_base + GT_COUNTER1);
> +       do {
> +               old_upper = upper;
> +               lower = __raw_readl(gt_base + GT_COUNTER0);
> +               upper = __raw_readl(gt_base + GT_COUNTER1);
> +       } while (upper != old_upper);
> +
> +       counter = upper;
> +       counter <<= 32;
> +       counter |= lower;
> +       return counter;
> +}

Please replace __raw_readl etc with the non-__raw variants
throughout the code.

The __raw accessors are not endian safe and are not meant
for device drivers. If you are worried about latency from
extra barriers, use readl_relaxed().

	Arnd

From mboxrd@z Thu Jan  1 00:00:00 1970
From: arnd@arndb.de (Arnd Bergmann)
Date: Thu, 20 Jun 2013 21:02:30 +0200
Subject: [PATCH v3 02/10] clocksource:arm_global_timer: Add ARM global
 timer support.
In-Reply-To: <1371737121-9295-1-git-send-email-srinivas.kandagatla@st.com>
References: <1371736996-8770-1-git-send-email-srinivas.kandagatla@st.com>
 <1371737121-9295-1-git-send-email-srinivas.kandagatla@st.com>
Message-ID: <201306202102.30478.arnd@arndb.de>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Thursday 20 June 2013, Srinivas KANDAGATLA wrote:
> +static u64 gt_counter_read(void)
> +{
> +       u64 counter;
> +       u32 lower;
> +       u32 upper, old_upper;
> +
> +       upper = __raw_readl(gt_base + GT_COUNTER1);
> +       do {
> +               old_upper = upper;
> +               lower = __raw_readl(gt_base + GT_COUNTER0);
> +               upper = __raw_readl(gt_base + GT_COUNTER1);
> +       } while (upper != old_upper);
> +
> +       counter = upper;
> +       counter <<= 32;
> +       counter |= lower;
> +       return counter;
> +}

Please replace __raw_readl etc with the non-__raw variants
throughout the code.

The __raw accessors are not endian safe and are not meant
for device drivers. If you are worried about latency from
extra barriers, use readl_relaxed().

	Arnd