From: Mandeep Singh Baines <msb@chromium.org>
To: Kukjin Kim <kgene.kim@samsung.com>, linux-kernel@vger.kernel.org
Cc: Mandeep Singh Baines <msb@chromium.org>,
Sonny Rao <sonnyrao@chromium.org>,
Olof Johansson <olofj@chromium.org>,
Russell King <linux@arm.linux.org.uk>,
linux-arm-kernel@lists.infradead.org,
linux-samsung-soc@vger.kernel.org
Subject: [PATCH] ARM: exynos: mct: cache mct upper count
Date: Wed, 5 Sep 2012 14:34:54 -0700 [thread overview]
Message-ID: <1346880894-31316-1-git-send-email-msb@chromium.org> (raw)
Saves one register read.
BUG=none
TEST=See below.
Before (perf report):
1.40% [k] exynos4_frc_read
|
|--87.20%-- ktime_get_ts
| |
| |--93.60%-- posix_ktime_get_ts
After (perf report):
1.00% [k] exynos4_frc_read
|
|--88.61%-- ktime_get_ts
| |
| |--92.70%-- posix_ktime_get_ts
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
CC: Sonny Rao <sonnyrao@chromium.org>
CC: Olof Johansson <olofj@chromium.org>
CC: Kukjin Kim <kgene.kim@samsung.com>
CC: Russell King <linux@arm.linux.org.uk>
CC: linux-arm-kernel@lists.infradead.org
CC: linux-samsung-soc@vger.kernel.org
---
arch/arm/mach-exynos/mct.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm/mach-exynos/mct.c b/arch/arm/mach-exynos/mct.c
index b601fb8..2bbd533 100644
--- a/arch/arm/mach-exynos/mct.c
+++ b/arch/arm/mach-exynos/mct.c
@@ -128,8 +128,8 @@ static void exynos4_mct_frc_start(u32 hi, u32 lo)
static cycle_t exynos4_frc_read(struct clocksource *cs)
{
- unsigned int lo, hi;
- u32 hi2 = __raw_readl(EXYNOS4_MCT_G_CNT_U);
+ u32 lo, hi;
+ static u32 hi2;
do {
hi = hi2;
--
1.7.7.3
next reply other threads:[~2012-09-05 21:35 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-05 21:34 Mandeep Singh Baines [this message]
2012-09-05 21:36 [PATCH] ARM: exynos: mct: cache mct upper count Mandeep Singh Baines
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