From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [PATCH 4/8] ARM: OMAP: 32k counter: Provide y2038-safe omap_read_persistent_clock() replacement Date: Wed, 11 Mar 2015 08:28:28 -0700 Message-ID: <20150311152827.GY5264@atomide.com> References: <1426043715-22043-1-git-send-email-xlpang@126.com> <1426043715-22043-5-git-send-email-xlpang@126.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1426043715-22043-5-git-send-email-xlpang@126.com> Sender: linux-kernel-owner@vger.kernel.org To: Xunlei Pang Cc: linux-kernel@vger.kernel.org, rtc-linux@googlegroups.com, Thomas Gleixner , Alessandro Zummo , John Stultz , Arnd Bergmann , linux-omap@vger.kernel.org, linux-tegra@vger.kernel.org, Stephen Warren , linux390@de.ibm.com, Martin Schwidefsky , Ralf Baechle , Arnd Bergmann , Xunlei Pang List-Id: linux-omap@vger.kernel.org * Xunlei Pang [150310 20:18]: > From: Xunlei Pang > > As part of addressing "y2038 problem" for in-kernel uses, this > patch adds the y2038-safe omap_read_persistent_clock64() using > timespec64. > > Because we rely on some subsequent changes to convert arm multiarch > support, omap_read_persistent_clock() will be removed then. > > Also remove the needless spinlock, because read_persistent_clock() > doesn't run simultaneously. > > Signed-off-by: Xunlei Pang Looks OK to me: Acked-by: Tony Lindgren > --- > arch/arm/plat-omap/counter_32k.c | 22 ++++++++++++---------- > 1 file changed, 12 insertions(+), 10 deletions(-) > > diff --git a/arch/arm/plat-omap/counter_32k.c b/arch/arm/plat-omap/counter_32k.c > index 61b4d70..d422e36 100644 > --- a/arch/arm/plat-omap/counter_32k.c > +++ b/arch/arm/plat-omap/counter_32k.c > @@ -44,24 +44,20 @@ static u64 notrace omap_32k_read_sched_clock(void) > } > > /** > - * omap_read_persistent_clock - Return time from a persistent clock. > + * omap_read_persistent_clock64 - Return time from a persistent clock. > * > * Reads the time from a source which isn't disabled during PM, the > * 32k sync timer. Convert the cycles elapsed since last read into > - * nsecs and adds to a monotonically increasing timespec. > + * nsecs and adds to a monotonically increasing timespec64. > */ > -static struct timespec persistent_ts; > +static struct timespec64 persistent_ts; > static cycles_t cycles; > static unsigned int persistent_mult, persistent_shift; > -static DEFINE_SPINLOCK(read_persistent_clock_lock); > > -static void omap_read_persistent_clock(struct timespec *ts) > +static void omap_read_persistent_clock64(struct timespec64 *ts) > { > unsigned long long nsecs; > cycles_t last_cycles; > - unsigned long flags; > - > - spin_lock_irqsave(&read_persistent_clock_lock, flags); > > last_cycles = cycles; > cycles = sync32k_cnt_reg ? readl_relaxed(sync32k_cnt_reg) : 0; > @@ -69,11 +65,17 @@ static void omap_read_persistent_clock(struct timespec *ts) > nsecs = clocksource_cyc2ns(cycles - last_cycles, > persistent_mult, persistent_shift); > > - timespec_add_ns(&persistent_ts, nsecs); > + timespec64_add_ns(&persistent_ts, nsecs); > > *ts = persistent_ts; > +} > + > +static void omap_read_persistent_clock(struct timespec *ts) > +{ > + struct timespec64 ts64; > > - spin_unlock_irqrestore(&read_persistent_clock_lock, flags); > + omap_read_persistent_clock64(&ts64); > + *ts = timespec64_to_timespec(ts64); > } > > /** > -- > 1.9.1 > >