[PATCH 2/2] clocksource: Make clocksource register functions void

[PATCH 2/2] clocksource: Make clocksource register functions void

[Yijing Wang]

Currently, clocksource_register() and __clocksource_register_scale()
functions always return 0, it's pointless, make functions void.
And remove the dead code that check the clocksource_register_hz()
return value.

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
---
 arch/arm/mach-davinci/time.c                    |    5 ++---
 arch/arm/mach-msm/timer.c                       |    4 +---
 arch/arm/mach-omap2/timer.c                     |    8 +++-----
 arch/avr32/kernel/time.c                        |    4 +---
 arch/blackfin/kernel/time-ts.c                  |    6 ++----
 arch/microblaze/kernel/timer.c                  |    3 +--
 arch/mips/jz4740/time.c                         |    6 +-----
 arch/mips/loongson/common/cs5536/cs5536_mfgpt.c |    3 ++-
 arch/openrisc/kernel/time.c                     |    3 +--
 arch/powerpc/kernel/time.c                      |    6 +-----
 arch/um/kernel/time.c                           |    6 +-----
 arch/x86/platform/uv/uv_time.c                  |   14 ++++++--------
 drivers/clocksource/acpi_pm.c                   |    3 ++-
 drivers/clocksource/cadence_ttc_timer.c         |    6 +-----
 drivers/clocksource/exynos_mct.c                |    4 +---
 drivers/clocksource/i8253.c                     |    3 ++-
 drivers/clocksource/mmio.c                      |    3 ++-
 drivers/clocksource/samsung_pwm_timer.c         |    5 +----
 drivers/clocksource/scx200_hrt.c                |    3 ++-
 drivers/clocksource/tcb_clksrc.c                |    8 +-------
 drivers/clocksource/timer-marco.c               |    2 +-
 drivers/clocksource/timer-prima2.c              |    2 +-
 drivers/clocksource/vt8500_timer.c              |    4 +---
 include/linux/clocksource.h                     |    8 ++++----
 kernel/time/clocksource.c                       |    6 ++----
 kernel/time/jiffies.c                           |    3 ++-
 26 files changed, 45 insertions(+), 83 deletions(-)

diff --git a/arch/arm/mach-davinci/time.c b/arch/arm/mach-davinci/time.c
index 56c6eb5..9536f85 100644
--- a/arch/arm/mach-davinci/time.c
+++ b/arch/arm/mach-davinci/time.c
@@ -387,9 +387,8 @@ void __init davinci_timer_init(void)
 
 	/* setup clocksource */
 	clocksource_davinci.name = id_to_name[clocksource_id];
-	if (clocksource_register_hz(&clocksource_davinci,
-				    davinci_clock_tick_rate))
-		printk(err, clocksource_davinci.name);
+	clocksource_register_hz(&clocksource_davinci,
+				    davinci_clock_tick_rate);
 
 	setup_sched_clock(davinci_read_sched_clock, 32,
 			  davinci_clock_tick_rate);
diff --git a/arch/arm/mach-msm/timer.c b/arch/arm/mach-msm/timer.c
index 1e9c338..c96e034 100644
--- a/arch/arm/mach-msm/timer.c
+++ b/arch/arm/mach-msm/timer.c
@@ -226,9 +226,7 @@ static void __init msm_timer_init(u32 dgt_hz, int sched_bits, int irq,
 
 err:
 	writel_relaxed(TIMER_ENABLE_EN, source_base + TIMER_ENABLE);
-	res = clocksource_register_hz(cs, dgt_hz);
-	if (res)
-		pr_err("clocksource_register failed\n");
+	clocksource_register_hz(cs, dgt_hz);
 	setup_sched_clock(msm_sched_clock_read, sched_bits, dgt_hz);
 }
 
diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c
index 3ca81e0..beaf7c7 100644
--- a/arch/arm/mach-omap2/timer.c
+++ b/arch/arm/mach-omap2/timer.c
@@ -473,11 +473,9 @@ static void __init omap2_gptimer_clocksource_init(int gptimer_id,
 				   OMAP_TIMER_NONPOSTED);
 	setup_sched_clock(dmtimer_read_sched_clock, 32, clksrc.rate);
 
-	if (clocksource_register_hz(&clocksource_gpt, clksrc.rate))
-		pr_err("Could not register clocksource %s\n",
-			clocksource_gpt.name);
-	else
-		pr_info("OMAP clocksource: %s at %lu Hz\n",
+	clocksource_register_hz(&clocksource_gpt, clksrc.rate);
+
+	pr_info("OMAP clocksource: %s at %lu Hz\n",
 			clocksource_gpt.name, clksrc.rate);
 }
 
diff --git a/arch/avr32/kernel/time.c b/arch/avr32/kernel/time.c
index d0f771b..51b4a66 100644
--- a/arch/avr32/kernel/time.c
+++ b/arch/avr32/kernel/time.c
@@ -134,9 +134,7 @@ void __init time_init(void)
 
 	/* figure rate for counter */
 	counter_hz = clk_get_rate(boot_cpu_data.clk);
-	ret = clocksource_register_hz(&counter, counter_hz);
-	if (ret)
-		pr_debug("timer: could not register clocksource: %d\n", ret);
+	clocksource_register_hz(&counter, counter_hz);
 
 	/* setup COMPARE clockevent */
 	comparator.mult = div_sc(counter_hz, NSEC_PER_SEC, comparator.shift);
diff --git a/arch/blackfin/kernel/time-ts.c b/arch/blackfin/kernel/time-ts.c
index cb0a484..df3bb08 100644
--- a/arch/blackfin/kernel/time-ts.c
+++ b/arch/blackfin/kernel/time-ts.c
@@ -51,8 +51,7 @@ static inline unsigned long long bfin_cs_cycles_sched_clock(void)
 
 static int __init bfin_cs_cycles_init(void)
 {
-	if (clocksource_register_hz(&bfin_cs_cycles, get_cclk()))
-		panic("failed to register clocksource");
+	clocksource_register_hz(&bfin_cs_cycles, get_cclk());
 
 	return 0;
 }
@@ -103,8 +102,7 @@ static int __init bfin_cs_gptimer0_init(void)
 {
 	setup_gptimer0();
 
-	if (clocksource_register_hz(&bfin_cs_gptimer0, get_sclk()))
-		panic("failed to register clocksource");
+	clocksource_register_hz(&bfin_cs_gptimer0, get_sclk());
 
 	return 0;
 }
diff --git a/arch/microblaze/kernel/timer.c b/arch/microblaze/kernel/timer.c
index 3e39b10..6a2417e 100644
--- a/arch/microblaze/kernel/timer.c
+++ b/arch/microblaze/kernel/timer.c
@@ -208,8 +208,7 @@ static struct clocksource clocksource_microblaze = {
 
 static int __init xilinx_clocksource_init(void)
 {
-	if (clocksource_register_hz(&clocksource_microblaze, timer_clock_freq))
-		panic("failed to register clocksource");
+	clocksource_register_hz(&clocksource_microblaze, timer_clock_freq);
 
 	/* stop timer1 */
 	out_be32(timer_baseaddr + TCSR1,
diff --git a/arch/mips/jz4740/time.c b/arch/mips/jz4740/time.c
index 5e430ce..041cdff 100644
--- a/arch/mips/jz4740/time.c
+++ b/arch/mips/jz4740/time.c
@@ -105,7 +105,6 @@ static struct irqaction timer_irqaction = {
 
 void __init plat_time_init(void)
 {
-	int ret;
 	uint32_t clk_rate;
 	uint16_t ctrl;
 
@@ -121,10 +120,7 @@ void __init plat_time_init(void)
 
 	clockevents_register_device(&jz4740_clockevent);
 
-	ret = clocksource_register_hz(&jz4740_clocksource, clk_rate);
-
-	if (ret)
-		printk(KERN_ERR "Failed to register clocksource: %d\n", ret);
+	clocksource_register_hz(&jz4740_clocksource, clk_rate);
 
 	setup_irq(JZ4740_IRQ_TCU0, &timer_irqaction);
 
diff --git a/arch/mips/loongson/common/cs5536/cs5536_mfgpt.c b/arch/mips/loongson/common/cs5536/cs5536_mfgpt.c
index c639b9d..9fa6d99 100644
--- a/arch/mips/loongson/common/cs5536/cs5536_mfgpt.c
+++ b/arch/mips/loongson/common/cs5536/cs5536_mfgpt.c
@@ -208,7 +208,8 @@ int __init init_mfgpt_clocksource(void)
 	if (num_possible_cpus() > 1)	/* MFGPT does not scale! */
 		return 0;
 
-	return clocksource_register_hz(&clocksource_mfgpt, MFGPT_TICK_RATE);
+	clocksource_register_hz(&clocksource_mfgpt, MFGPT_TICK_RATE);
+	return 0;
 }
 
 arch_initcall(init_mfgpt_clocksource);
diff --git a/arch/openrisc/kernel/time.c b/arch/openrisc/kernel/time.c
index 7c52e94..3f789aa 100644
--- a/arch/openrisc/kernel/time.c
+++ b/arch/openrisc/kernel/time.c
@@ -156,8 +156,7 @@ static struct clocksource openrisc_timer = {
 
 static int __init openrisc_timer_init(void)
 {
-	if (clocksource_register_hz(&openrisc_timer, cpuinfo.clock_frequency))
-		panic("failed to register clocksource");
+	clocksource_register_hz(&openrisc_timer, cpuinfo.clock_frequency);
 
 	/* Enable the incrementer: 'continuous' mode with interrupt disabled */
 	mtspr(SPR_TTMR, SPR_TTMR_CR);
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index b3b1441..27c0627 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -788,11 +788,7 @@ static void __init clocksource_init(void)
 	else
 		clock = &clocksource_timebase;
 
-	if (clocksource_register_hz(clock, tb_ticks_per_sec)) {
-		printk(KERN_ERR "clocksource: %s is already registered\n",
-		       clock->name);
-		return;
-	}
+	clocksource_register_hz(clock, tb_ticks_per_sec);
 
 	printk(KERN_INFO "clocksource: %s mult[%x] shift[%d] registered\n",
 	       clock->name, clock->mult, clock->shift);
diff --git a/arch/um/kernel/time.c b/arch/um/kernel/time.c
index 117568d..2034b58 100644
--- a/arch/um/kernel/time.c
+++ b/arch/um/kernel/time.c
@@ -92,11 +92,7 @@ static void __init setup_itimer(void)
 		clockevent_delta2ns(60 * HZ, &itimer_clockevent);
 	itimer_clockevent.min_delta_ns =
 		clockevent_delta2ns(1, &itimer_clockevent);
-	err = clocksource_register_hz(&itimer_clocksource, USEC_PER_SEC);
-	if (err) {
-		printk(KERN_ERR "clocksource_register_hz returned %d\n", err);
-		return;
-	}
+	clocksource_register_hz(&itimer_clocksource, USEC_PER_SEC);
 	clockevents_register_device(&itimer_clockevent);
 }
 
diff --git a/arch/x86/platform/uv/uv_time.c b/arch/x86/platform/uv/uv_time.c
index 5c86786..b963774 100644
--- a/arch/x86/platform/uv/uv_time.c
+++ b/arch/x86/platform/uv/uv_time.c
@@ -379,15 +379,13 @@ static __init int uv_rtc_setup_clock(void)
 	if (!is_uv_system())
 		return -ENODEV;
 
-	rc = clocksource_register_hz(&clocksource_uv, sn_rtc_cycles_per_second);
-	if (rc)
-		printk(KERN_INFO "UV RTC clocksource failed rc %d\n", rc);
-	else
-		printk(KERN_INFO "UV RTC clocksource registered freq %lu MHz\n",
-			sn_rtc_cycles_per_second/(unsigned long)1E6);
+	clocksource_register_hz(&clocksource_uv, sn_rtc_cycles_per_second);
+
+	pr_info("UV RTC clocksource registered freq %lu MHz\n",
+		sn_rtc_cycles_per_second/(unsigned long)1E6);
 
-	if (rc || !uv_rtc_evt_enable || x86_platform_ipi_callback)
-		return rc;
+	if (!uv_rtc_evt_enable || x86_platform_ipi_callback)
+		return 0;
 
 	/* Setup and register clockevents */
 	rc = uv_rtc_allocate_timers();
diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c
index 6eab889..ab1dc63 100644
--- a/drivers/clocksource/acpi_pm.c
+++ b/drivers/clocksource/acpi_pm.c
@@ -218,8 +218,9 @@ static int __init init_acpi_pm_clocksource(void)
 		return -ENODEV;
 	}
 
-	return clocksource_register_hz(&clocksource_acpi_pm,
+	clocksource_register_hz(&clocksource_acpi_pm,
 						PMTMR_TICKS_PER_SEC);
+	return 0;
 }
 
 /* We use fs_initcall because we want the PCI fixups to have run
diff --git a/drivers/clocksource/cadence_ttc_timer.c b/drivers/clocksource/cadence_ttc_timer.c
index 63f176d..b9b56ed 100644
--- a/drivers/clocksource/cadence_ttc_timer.c
+++ b/drivers/clocksource/cadence_ttc_timer.c
@@ -301,11 +301,7 @@ static void __init ttc_setup_clocksource(struct clk *clk, void __iomem *base)
 	__raw_writel(CNT_CNTRL_RESET,
 		     ttccs->ttc.base_addr + TTC_CNT_CNTRL_OFFSET);
 
-	err = clocksource_register_hz(&ttccs->cs, ttccs->ttc.freq / PRESCALE);
-	if (WARN_ON(err)) {
-		kfree(ttccs);
-		return;
-	}
+	clocksource_register_hz(&ttccs->cs, ttccs->ttc.freq / PRESCALE);
 
 	ttc_sched_clock_val_reg = base + TTC_COUNT_VAL_OFFSET;
 	sched_clock_register(ttc_sched_clock_read, 16, ttccs->ttc.freq / PRESCALE);
diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c
index 62b0de6..98649c7 100644
--- a/drivers/clocksource/exynos_mct.c
+++ b/drivers/clocksource/exynos_mct.c
@@ -193,9 +193,7 @@ struct clocksource mct_frc = {
 static void __init exynos4_clocksource_init(void)
 {
 	exynos4_mct_frc_start(0, 0);
-
-	if (clocksource_register_hz(&mct_frc, clk_rate))
-		panic("%s: can't register clocksource\n", mct_frc.name);
+	clocksource_register_hz(&mct_frc, clk_rate);
 }
 
 static void exynos4_mct_comp0_stop(void)
diff --git a/drivers/clocksource/i8253.c b/drivers/clocksource/i8253.c
index 14ee3ef..9c45f0a 100644
--- a/drivers/clocksource/i8253.c
+++ b/drivers/clocksource/i8253.c
@@ -95,7 +95,8 @@ static struct clocksource i8253_cs = {
 
 int __init clocksource_i8253_init(void)
 {
-	return clocksource_register_hz(&i8253_cs, PIT_TICK_RATE);
+	clocksource_register_hz(&i8253_cs, PIT_TICK_RATE);
+	return 0;
 }
 #endif
 
diff --git a/drivers/clocksource/mmio.c b/drivers/clocksource/mmio.c
index c0e2512..6e0b530 100644
--- a/drivers/clocksource/mmio.c
+++ b/drivers/clocksource/mmio.c
@@ -69,5 +69,6 @@ int __init clocksource_mmio_init(void __iomem *base, const char *name,
 	cs->clksrc.mask = CLOCKSOURCE_MASK(bits);
 	cs->clksrc.flags = CLOCK_SOURCE_IS_CONTINUOUS;
 
-	return clocksource_register_hz(&cs->clksrc, hz);
+	clocksource_register_hz(&cs->clksrc, hz);
+	return 0;
 }
diff --git a/drivers/clocksource/samsung_pwm_timer.c b/drivers/clocksource/samsung_pwm_timer.c
index 5645cfc..c59292f 100644
--- a/drivers/clocksource/samsung_pwm_timer.c
+++ b/drivers/clocksource/samsung_pwm_timer.c
@@ -340,7 +340,6 @@ static void __init samsung_clocksource_init(void)
 {
 	unsigned long pclk;
 	unsigned long clock_rate;
-	int ret;
 
 	pclk = clk_get_rate(pwm.timerclk);
 
@@ -361,9 +360,7 @@ static void __init samsung_clocksource_init(void)
 						pwm.variant.bits, clock_rate);
 
 	samsung_clocksource.mask = CLOCKSOURCE_MASK(pwm.variant.bits);
-	ret = clocksource_register_hz(&samsung_clocksource, clock_rate);
-	if (ret)
-		panic("samsung_clocksource_timer: can't register clocksource\n");
+	clocksource_register_hz(&samsung_clocksource, clock_rate);
 }
 
 static void __init samsung_timer_resources(void)
diff --git a/drivers/clocksource/scx200_hrt.c b/drivers/clocksource/scx200_hrt.c
index 64f9e82..57bdc04 100644
--- a/drivers/clocksource/scx200_hrt.c
+++ b/drivers/clocksource/scx200_hrt.c
@@ -83,7 +83,8 @@ static int __init init_hrt_clocksource(void)
 
 	pr_info("enabling scx200 high-res timer (%s MHz +%d ppm)\n", mhz27 ? "27":"1", ppm);
 
-	return clocksource_register_hz(&cs_hrt, freq);
+	clocksource_register_hz(&cs_hrt, freq);
+	return 0;
 }
 
 module_init(init_hrt_clocksource);
diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
index 00fdd11..805245d 100644
--- a/drivers/clocksource/tcb_clksrc.c
+++ b/drivers/clocksource/tcb_clksrc.c
@@ -340,9 +340,7 @@ static int __init tcb_clksrc_init(void)
 	}
 
 	/* and away we go! */
-	ret = clocksource_register_hz(&clksrc, divided_rate);
-	if (ret)
-		goto err_disable_t1;
+	clocksource_register_hz(&clksrc, divided_rate);
 
 	/* channel 2:  periodic and oneshot timer support */
 	ret = setup_clkevents(tc, clk32k_divisor_idx);
@@ -354,10 +352,6 @@ static int __init tcb_clksrc_init(void)
 err_unregister_clksrc:
 	clocksource_unregister(&clksrc);
 
-err_disable_t1:
-	if (!tc->tcb_config || tc->tcb_config->counter_width != 32)
-		clk_disable_unprepare(tc->clk[1]);
-
 err_disable_t0:
 	clk_disable_unprepare(t0_clk);
 
diff --git a/drivers/clocksource/timer-marco.c b/drivers/clocksource/timer-marco.c
index 09a17d9..ae78ce0 100644
--- a/drivers/clocksource/timer-marco.c
+++ b/drivers/clocksource/timer-marco.c
@@ -283,7 +283,7 @@ static void __init sirfsoc_marco_timer_init(void)
 	/* Clear all interrupts */
 	writel_relaxed(0xFFFF, sirfsoc_timer_base + SIRFSOC_TIMER_INTR_STATUS);
 
-	BUG_ON(clocksource_register_hz(&sirfsoc_clocksource, CLOCK_TICK_RATE));
+	clocksource_register_hz(&sirfsoc_clocksource, CLOCK_TICK_RATE);
 
 	sirfsoc_clockevent_init();
 }
diff --git a/drivers/clocksource/timer-prima2.c b/drivers/clocksource/timer-prima2.c
index 8a492d3..c9cc307 100644
--- a/drivers/clocksource/timer-prima2.c
+++ b/drivers/clocksource/timer-prima2.c
@@ -204,7 +204,7 @@ static void __init sirfsoc_prima2_timer_init(struct device_node *np)
 	writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_HI);
 	writel_relaxed(BIT(0), sirfsoc_timer_base + SIRFSOC_TIMER_STATUS);
 
-	BUG_ON(clocksource_register_hz(&sirfsoc_clocksource, CLOCK_TICK_RATE));
+	clocksource_register_hz(&sirfsoc_clocksource, CLOCK_TICK_RATE);
 
 	sched_clock_register(sirfsoc_read_sched_clock, 64, CLOCK_TICK_RATE);
 
diff --git a/drivers/clocksource/vt8500_timer.c b/drivers/clocksource/vt8500_timer.c
index 1098ed3..13f5fa4 100644
--- a/drivers/clocksource/vt8500_timer.c
+++ b/drivers/clocksource/vt8500_timer.c
@@ -150,9 +150,7 @@ static void __init vt8500_timer_init(struct device_node *np)
 	writel(0xf, regbase + TIMER_STATUS_VAL);
 	writel(~0, regbase + TIMER_MATCH_VAL);
 
-	if (clocksource_register_hz(&clocksource, VT8500_TIMER_HZ))
-		pr_err("%s: vt8500_timer_init: clocksource_register failed for %s\n",
-					__func__, clocksource.name);
+	clocksource_register_hz(&clocksource, VT8500_TIMER_HZ);
 
 	clockevent.cpumask = cpumask_of(0);
 
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index 67301a4..5a17c5e 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -282,7 +282,7 @@ static inline s64 clocksource_cyc2ns(cycle_t cycles, u32 mult, u32 shift)
 }
 
 
-extern int clocksource_register(struct clocksource*);
+extern void clocksource_register(struct clocksource *);
 extern int clocksource_unregister(struct clocksource*);
 extern void clocksource_touch_watchdog(void);
 extern struct clocksource* clocksource_get_next(void);
@@ -301,17 +301,17 @@ clocks_calc_mult_shift(u32 *mult, u32 *shift, u32 from, u32 to, u32 minsec);
  * Don't call __clocksource_register_scale directly, use
  * clocksource_register_hz/khz
  */
-extern int
+extern void
 __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq);
 extern void
 __clocksource_updatefreq_scale(struct clocksource *cs, u32 scale, u32 freq);
 
-static inline int clocksource_register_hz(struct clocksource *cs, u32 hz)
+static inline void clocksource_register_hz(struct clocksource *cs, u32 hz)
 {
 	return __clocksource_register_scale(cs, 1, hz);
 }
 
-static inline int clocksource_register_khz(struct clocksource *cs, u32 khz)
+static inline void clocksource_register_khz(struct clocksource *cs, u32 khz)
 {
 	return __clocksource_register_scale(cs, 1000, khz);
 }
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 9951575..686ff72 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -782,7 +782,7 @@ EXPORT_SYMBOL_GPL(__clocksource_updatefreq_scale);
  * This *SHOULD NOT* be called directly! Please use the
  * clocksource_register_hz() or clocksource_register_khz helper functions.
  */
-int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq)
+void __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq)
 {
 
 	/* Initialize mult/shift and max_idle_ns */
@@ -794,7 +794,6 @@ int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq)
 	clocksource_enqueue_watchdog(cs);
 	clocksource_select();
 	mutex_unlock(&clocksource_mutex);
-	return 0;
 }
 EXPORT_SYMBOL_GPL(__clocksource_register_scale);
 
@@ -804,7 +803,7 @@ EXPORT_SYMBOL_GPL(__clocksource_register_scale);
  * @cs:		clocksource to be registered
  *
  */
-int clocksource_register(struct clocksource *cs)
+void clocksource_register(struct clocksource *cs)
 {
 	/* calculate max adjustment for given mult/shift */
 	cs->maxadj = clocksource_max_adjustment(cs);
@@ -820,7 +819,6 @@ int clocksource_register(struct clocksource *cs)
 	clocksource_enqueue_watchdog(cs);
 	clocksource_select();
 	mutex_unlock(&clocksource_mutex);
-	return 0;
 }
 EXPORT_SYMBOL(clocksource_register);
 
diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c
index 7a925ba..ae4c534 100644
--- a/kernel/time/jiffies.c
+++ b/kernel/time/jiffies.c
@@ -88,7 +88,8 @@ EXPORT_SYMBOL(jiffies);
 
 static int __init init_jiffies_clocksource(void)
 {
-	return clocksource_register(&clocksource_jiffies);
+	clocksource_register(&clocksource_jiffies);
+	return 0;
 }
 
 core_initcall(init_jiffies_clocksource);
-- 
1.7.1

[PATCH 2/2] clocksource: Make clocksource register functions void

[Hans-Christian Egtvedt]

Around Thu 23 Jan 2014 15:12:46 +0800 or thereabout, Yijing Wang wrote:
> Currently, clocksource_register() and __clocksource_register_scale()
> functions always return 0, it's pointless, make functions void.
> And remove the dead code that check the clocksource_register_hz()
> return value.
> 
> Signed-off-by: Yijing Wang <wangyijing@huawei.com>

For the avr32 related change

Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no>

> ---
>  arch/arm/mach-davinci/time.c                    |    5 ++---
>  arch/arm/mach-msm/timer.c                       |    4 +---
>  arch/arm/mach-omap2/timer.c                     |    8 +++-----
>  arch/avr32/kernel/time.c                        |    4 +---
>  arch/blackfin/kernel/time-ts.c                  |    6 ++----
>  arch/microblaze/kernel/timer.c                  |    3 +--
>  arch/mips/jz4740/time.c                         |    6 +-----
>  arch/mips/loongson/common/cs5536/cs5536_mfgpt.c |    3 ++-
>  arch/openrisc/kernel/time.c                     |    3 +--
>  arch/powerpc/kernel/time.c                      |    6 +-----
>  arch/um/kernel/time.c                           |    6 +-----
>  arch/x86/platform/uv/uv_time.c                  |   14 ++++++--------
>  drivers/clocksource/acpi_pm.c                   |    3 ++-
>  drivers/clocksource/cadence_ttc_timer.c         |    6 +-----
>  drivers/clocksource/exynos_mct.c                |    4 +---
>  drivers/clocksource/i8253.c                     |    3 ++-
>  drivers/clocksource/mmio.c                      |    3 ++-
>  drivers/clocksource/samsung_pwm_timer.c         |    5 +----
>  drivers/clocksource/scx200_hrt.c                |    3 ++-
>  drivers/clocksource/tcb_clksrc.c                |    8 +-------
>  drivers/clocksource/timer-marco.c               |    2 +-
>  drivers/clocksource/timer-prima2.c              |    2 +-
>  drivers/clocksource/vt8500_timer.c              |    4 +---
>  include/linux/clocksource.h                     |    8 ++++----
>  kernel/time/clocksource.c                       |    6 ++----
>  kernel/time/jiffies.c                           |    3 ++-
>  26 files changed, 45 insertions(+), 83 deletions(-)

<snipp diffs>

-- 
HcE

[PATCH 2/2] clocksource: Make clocksource register functions void

[Tony Prisk]

On 23/01/14 20:12, Yijing Wang wrote:
> Currently, clocksource_register() and __clocksource_register_scale()
> functions always return 0, it's pointless, make functions void.
> And remove the dead code that check the clocksource_register_hz()
> return value.
>
> Signed-off-by: Yijing Wang <wangyijing@huawei.com>
......
> diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
> index 67301a4..5a17c5e 100644
> --- a/include/linux/clocksource.h
> +++ b/include/linux/clocksource.h
> @@ -282,7 +282,7 @@ static inline s64 clocksource_cyc2ns(cycle_t cycles, u32 mult, u32 shift)
>   }
>   
>   
> -extern int clocksource_register(struct clocksource*);
> +extern void clocksource_register(struct clocksource *);
>   extern int clocksource_unregister(struct clocksource*);
>   extern void clocksource_touch_watchdog(void);
>   extern struct clocksource* clocksource_get_next(void);
> @@ -301,17 +301,17 @@ clocks_calc_mult_shift(u32 *mult, u32 *shift, u32 from, u32 to, u32 minsec);
>    * Don't call __clocksource_register_scale directly, use
>    * clocksource_register_hz/khz
>    */
> -extern int
> +extern void
>   __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq);
>   extern void
>   __clocksource_updatefreq_scale(struct clocksource *cs, u32 scale, u32 freq);
>   
> -static inline int clocksource_register_hz(struct clocksource *cs, u32 hz)
> +static inline void clocksource_register_hz(struct clocksource *cs, u32 hz)
>   {
>   	return __clocksource_register_scale(cs, 1, hz);
>   }

This doesn't make sense - you are still returning a value on a function 
declared void, and the return is now from a function that doesn't return 
anything either ?!?!
Doesn't this throw a compile-time warning??

Regards
Tony Prisk

[PATCH 2/2] clocksource: Make clocksource register functions void

[Geert Uytterhoeven]

On Thu, Jan 23, 2014 at 8:45 AM, Tony Prisk <linux@prisktech.co.nz> wrote:
>>   -static inline int clocksource_register_hz(struct clocksource *cs, u32
>> hz)
>> +static inline void clocksource_register_hz(struct clocksource *cs, u32
>> hz)
>>   {
>>         return __clocksource_register_scale(cs, 1, hz);
>>   }
>
>
> This doesn't make sense - you are still returning a value on a function
> declared void, and the return is now from a function that doesn't return
> anything either ?!?!
> Doesn't this throw a compile-time warning??

No, passing on void in functions returning void doesn't cause compiler
warnings.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

[PATCH 2/2] clocksource: Make clocksource register functions void

[Tony Prisk]

On 23/01/14 20:58, Geert Uytterhoeven wrote:
> On Thu, Jan 23, 2014 at 8:45 AM, Tony Prisk <linux@prisktech.co.nz> wrote:
>>>    -static inline int clocksource_register_hz(struct clocksource *cs, u32
>>> hz)
>>> +static inline void clocksource_register_hz(struct clocksource *cs, u32
>>> hz)
>>>    {
>>>          return __clocksource_register_scale(cs, 1, hz);
>>>    }
>>
>> This doesn't make sense - you are still returning a value on a function
>> declared void, and the return is now from a function that doesn't return
>> anything either ?!?!
>> Doesn't this throw a compile-time warning??
> No, passing on void in functions returning void doesn't cause compiler
> warnings.
>
> Gr{oetje,eeting}s,
>
>                          Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                  -- Linus Torvalds
Doesn't seem right to me (even if there is no warning) but that's 
probably because I used to program in Pascal where functions with no 
return were 'procedures' :)
Whether it needs to be changed or not:

For the vt8500 part -
Acked-by: Tony Prisk <linux@prisktech.co.nz>

Regards
Tony Prisk

[PATCH 2/2] clocksource: Make clocksource register functions void

[Yijing Wang]

On 2014/1/23 16:04, Tony Prisk wrote:
> On 23/01/14 20:58, Geert Uytterhoeven wrote:
>> On Thu, Jan 23, 2014 at 8:45 AM, Tony Prisk <linux@prisktech.co.nz> wrote:
>>>>    -static inline int clocksource_register_hz(struct clocksource *cs, u32
>>>> hz)
>>>> +static inline void clocksource_register_hz(struct clocksource *cs, u32
>>>> hz)
>>>>    {
>>>>          return __clocksource_register_scale(cs, 1, hz);
>>>>    }
>>>
>>> This doesn't make sense - you are still returning a value on a function
>>> declared void, and the return is now from a function that doesn't return
>>> anything either ?!?!
>>> Doesn't this throw a compile-time warning??
>> No, passing on void in functions returning void doesn't cause compiler
>> warnings.
>>
>> Gr{oetje,eeting}s,
>>
>>                          Geert
>>
>> -- 
>> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org
>>
>> In personal conversations with technical people, I call myself a hacker. But
>> when I'm talking to journalists I just say "programmer" or something like that.
>>                                  -- Linus Torvalds
> Doesn't seem right to me (even if there is no warning) but that's probably because I used to program in Pascal where functions with no return were 'procedures' :)
> Whether it needs to be changed or not:
> 
> For the vt8500 part -
> Acked-by: Tony Prisk <linux@prisktech.co.nz>

Thanks!

> 
> Regards
> Tony Prisk
> 
> 
> .
> 


-- 
Thanks!
Yijing

[PATCH 2/2] clocksource: Make clocksource register functions void

[David Laight]

From: Linuxppc-dev Tony Prisk
> On 23/01/14 20:12, Yijing Wang wrote:
> > Currently, clocksource_register() and __clocksource_register_scale()
> > functions always return 0, it's pointless, make functions void.
> > And remove the dead code that check the clocksource_register_hz()
> > return value.
> ......
> > -static inline int clocksource_register_hz(struct clocksource *cs, u32 hz)
> > +static inline void clocksource_register_hz(struct clocksource *cs, u32 hz)
> >   {
> >   	return __clocksource_register_scale(cs, 1, hz);
> >   }
> 
> This doesn't make sense - you are still returning a value on a function
> declared void, and the return is now from a function that doesn't return
> anything either ?!?!
> Doesn't this throw a compile-time warning??

It depends on the compiler.
Recent gcc allow it.
I don't know if it is actually valid C though.

There is no excuse for it on lines like the above though.

	David

[PATCH 2/2] clocksource: Make clocksource register functions void

[Thomas Gleixner]

Yijing,

On Thu, 23 Jan 2014, David Laight wrote:

> From: Linuxppc-dev Tony Prisk
> > On 23/01/14 20:12, Yijing Wang wrote:
> > > Currently, clocksource_register() and __clocksource_register_scale()
> > > functions always return 0, it's pointless, make functions void.
> > > And remove the dead code that check the clocksource_register_hz()
> > > return value.
> > ......
> > > -static inline int clocksource_register_hz(struct clocksource *cs, u32 hz)
> > > +static inline void clocksource_register_hz(struct clocksource *cs, u32 hz)
> > >   {
> > >   	return __clocksource_register_scale(cs, 1, hz);
> > >   }
> > 
> > This doesn't make sense - you are still returning a value on a function
> > declared void, and the return is now from a function that doesn't return
> > anything either ?!?!
> > Doesn't this throw a compile-time warning??
> 
> It depends on the compiler.
> Recent gcc allow it.
> I don't know if it is actually valid C though.
> 
> There is no excuse for it on lines like the above though.

Can you please resend with that fixed against 3.14-rc1 ?

Thanks,

	tglx

[PATCH 2/2] clocksource: Make clocksource register functions void

[Yijing Wang]

On 2014/2/6 4:40, Thomas Gleixner wrote:
> Yijing,
> 
> On Thu, 23 Jan 2014, David Laight wrote:
> 
>> From: Linuxppc-dev Tony Prisk
>>> On 23/01/14 20:12, Yijing Wang wrote:
>>>> Currently, clocksource_register() and __clocksource_register_scale()
>>>> functions always return 0, it's pointless, make functions void.
>>>> And remove the dead code that check the clocksource_register_hz()
>>>> return value.
>>> ......
>>>> -static inline int clocksource_register_hz(struct clocksource *cs, u32 hz)
>>>> +static inline void clocksource_register_hz(struct clocksource *cs, u32 hz)
>>>>   {
>>>>   	return __clocksource_register_scale(cs, 1, hz);
>>>>   }
>>>
>>> This doesn't make sense - you are still returning a value on a function
>>> declared void, and the return is now from a function that doesn't return
>>> anything either ?!?!
>>> Doesn't this throw a compile-time warning??
>>
>> It depends on the compiler.
>> Recent gcc allow it.
>> I don't know if it is actually valid C though.
>>
>> There is no excuse for it on lines like the above though.
> 
> Can you please resend with that fixed against 3.14-rc1 ?

OK, I will resend later.

Thanks!
Yijing.


> 
> .
> 


-- 
Thanks!
Yijing

[PATCH 2/2] clocksource: Make clocksource register functions void

[Daniel Lezcano]

On 01/23/2014 08:12 AM, Yijing Wang wrote:
> Currently, clocksource_register() and __clocksource_register_scale()
> functions always return 0, it's pointless, make functions void.
> And remove the dead code that check the clocksource_register_hz()
> return value.
>
> Signed-off-by: Yijing Wang <wangyijing@huawei.com>

Well, do we really want to change all these files to not take care of a 
return value ? What about is we have to check it again later ?

I would recommend to investigate __clocksource_register_scale and the 
underneath functions if there is not an error to be returned in the call 
stack somewhere which is ignored today.

The same applies for clocksource_register.

Thanks
   -- Daniel

> ---
>   arch/arm/mach-davinci/time.c                    |    5 ++---
>   arch/arm/mach-msm/timer.c                       |    4 +---
>   arch/arm/mach-omap2/timer.c                     |    8 +++-----
>   arch/avr32/kernel/time.c                        |    4 +---
>   arch/blackfin/kernel/time-ts.c                  |    6 ++----
>   arch/microblaze/kernel/timer.c                  |    3 +--
>   arch/mips/jz4740/time.c                         |    6 +-----
>   arch/mips/loongson/common/cs5536/cs5536_mfgpt.c |    3 ++-
>   arch/openrisc/kernel/time.c                     |    3 +--
>   arch/powerpc/kernel/time.c                      |    6 +-----
>   arch/um/kernel/time.c                           |    6 +-----
>   arch/x86/platform/uv/uv_time.c                  |   14 ++++++--------
>   drivers/clocksource/acpi_pm.c                   |    3 ++-
>   drivers/clocksource/cadence_ttc_timer.c         |    6 +-----
>   drivers/clocksource/exynos_mct.c                |    4 +---
>   drivers/clocksource/i8253.c                     |    3 ++-
>   drivers/clocksource/mmio.c                      |    3 ++-
>   drivers/clocksource/samsung_pwm_timer.c         |    5 +----
>   drivers/clocksource/scx200_hrt.c                |    3 ++-
>   drivers/clocksource/tcb_clksrc.c                |    8 +-------
>   drivers/clocksource/timer-marco.c               |    2 +-
>   drivers/clocksource/timer-prima2.c              |    2 +-
>   drivers/clocksource/vt8500_timer.c              |    4 +---
>   include/linux/clocksource.h                     |    8 ++++----
>   kernel/time/clocksource.c                       |    6 ++----
>   kernel/time/jiffies.c                           |    3 ++-
>   26 files changed, 45 insertions(+), 83 deletions(-)
>
> diff --git a/arch/arm/mach-davinci/time.c b/arch/arm/mach-davinci/time.c
> index 56c6eb5..9536f85 100644
> --- a/arch/arm/mach-davinci/time.c
> +++ b/arch/arm/mach-davinci/time.c
> @@ -387,9 +387,8 @@ void __init davinci_timer_init(void)
>
>   	/* setup clocksource */
>   	clocksource_davinci.name = id_to_name[clocksource_id];
> -	if (clocksource_register_hz(&clocksource_davinci,
> -				    davinci_clock_tick_rate))
> -		printk(err, clocksource_davinci.name);
> +	clocksource_register_hz(&clocksource_davinci,
> +				    davinci_clock_tick_rate);
>
>   	setup_sched_clock(davinci_read_sched_clock, 32,
>   			  davinci_clock_tick_rate);
> diff --git a/arch/arm/mach-msm/timer.c b/arch/arm/mach-msm/timer.c
> index 1e9c338..c96e034 100644
> --- a/arch/arm/mach-msm/timer.c
> +++ b/arch/arm/mach-msm/timer.c
> @@ -226,9 +226,7 @@ static void __init msm_timer_init(u32 dgt_hz, int sched_bits, int irq,
>
>   err:
>   	writel_relaxed(TIMER_ENABLE_EN, source_base + TIMER_ENABLE);
> -	res = clocksource_register_hz(cs, dgt_hz);
> -	if (res)
> -		pr_err("clocksource_register failed\n");
> +	clocksource_register_hz(cs, dgt_hz);
>   	setup_sched_clock(msm_sched_clock_read, sched_bits, dgt_hz);
>   }
>
> diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c
> index 3ca81e0..beaf7c7 100644
> --- a/arch/arm/mach-omap2/timer.c
> +++ b/arch/arm/mach-omap2/timer.c
> @@ -473,11 +473,9 @@ static void __init omap2_gptimer_clocksource_init(int gptimer_id,
>   				   OMAP_TIMER_NONPOSTED);
>   	setup_sched_clock(dmtimer_read_sched_clock, 32, clksrc.rate);
>
> -	if (clocksource_register_hz(&clocksource_gpt, clksrc.rate))
> -		pr_err("Could not register clocksource %s\n",
> -			clocksource_gpt.name);
> -	else
> -		pr_info("OMAP clocksource: %s at %lu Hz\n",
> +	clocksource_register_hz(&clocksource_gpt, clksrc.rate);
> +
> +	pr_info("OMAP clocksource: %s at %lu Hz\n",
>   			clocksource_gpt.name, clksrc.rate);
>   }
>
> diff --git a/arch/avr32/kernel/time.c b/arch/avr32/kernel/time.c
> index d0f771b..51b4a66 100644
> --- a/arch/avr32/kernel/time.c
> +++ b/arch/avr32/kernel/time.c
> @@ -134,9 +134,7 @@ void __init time_init(void)
>
>   	/* figure rate for counter */
>   	counter_hz = clk_get_rate(boot_cpu_data.clk);
> -	ret = clocksource_register_hz(&counter, counter_hz);
> -	if (ret)
> -		pr_debug("timer: could not register clocksource: %d\n", ret);
> +	clocksource_register_hz(&counter, counter_hz);
>
>   	/* setup COMPARE clockevent */
>   	comparator.mult = div_sc(counter_hz, NSEC_PER_SEC, comparator.shift);
> diff --git a/arch/blackfin/kernel/time-ts.c b/arch/blackfin/kernel/time-ts.c
> index cb0a484..df3bb08 100644
> --- a/arch/blackfin/kernel/time-ts.c
> +++ b/arch/blackfin/kernel/time-ts.c
> @@ -51,8 +51,7 @@ static inline unsigned long long bfin_cs_cycles_sched_clock(void)
>
>   static int __init bfin_cs_cycles_init(void)
>   {
> -	if (clocksource_register_hz(&bfin_cs_cycles, get_cclk()))
> -		panic("failed to register clocksource");
> +	clocksource_register_hz(&bfin_cs_cycles, get_cclk());
>
>   	return 0;
>   }
> @@ -103,8 +102,7 @@ static int __init bfin_cs_gptimer0_init(void)
>   {
>   	setup_gptimer0();
>
> -	if (clocksource_register_hz(&bfin_cs_gptimer0, get_sclk()))
> -		panic("failed to register clocksource");
> +	clocksource_register_hz(&bfin_cs_gptimer0, get_sclk());
>
>   	return 0;
>   }
> diff --git a/arch/microblaze/kernel/timer.c b/arch/microblaze/kernel/timer.c
> index 3e39b10..6a2417e 100644
> --- a/arch/microblaze/kernel/timer.c
> +++ b/arch/microblaze/kernel/timer.c
> @@ -208,8 +208,7 @@ static struct clocksource clocksource_microblaze = {
>
>   static int __init xilinx_clocksource_init(void)
>   {
> -	if (clocksource_register_hz(&clocksource_microblaze, timer_clock_freq))
> -		panic("failed to register clocksource");
> +	clocksource_register_hz(&clocksource_microblaze, timer_clock_freq);
>
>   	/* stop timer1 */
>   	out_be32(timer_baseaddr + TCSR1,
> diff --git a/arch/mips/jz4740/time.c b/arch/mips/jz4740/time.c
> index 5e430ce..041cdff 100644
> --- a/arch/mips/jz4740/time.c
> +++ b/arch/mips/jz4740/time.c
> @@ -105,7 +105,6 @@ static struct irqaction timer_irqaction = {
>
>   void __init plat_time_init(void)
>   {
> -	int ret;
>   	uint32_t clk_rate;
>   	uint16_t ctrl;
>
> @@ -121,10 +120,7 @@ void __init plat_time_init(void)
>
>   	clockevents_register_device(&jz4740_clockevent);
>
> -	ret = clocksource_register_hz(&jz4740_clocksource, clk_rate);
> -
> -	if (ret)
> -		printk(KERN_ERR "Failed to register clocksource: %d\n", ret);
> +	clocksource_register_hz(&jz4740_clocksource, clk_rate);
>
>   	setup_irq(JZ4740_IRQ_TCU0, &timer_irqaction);
>
> diff --git a/arch/mips/loongson/common/cs5536/cs5536_mfgpt.c b/arch/mips/loongson/common/cs5536/cs5536_mfgpt.c
> index c639b9d..9fa6d99 100644
> --- a/arch/mips/loongson/common/cs5536/cs5536_mfgpt.c
> +++ b/arch/mips/loongson/common/cs5536/cs5536_mfgpt.c
> @@ -208,7 +208,8 @@ int __init init_mfgpt_clocksource(void)
>   	if (num_possible_cpus() > 1)	/* MFGPT does not scale! */
>   		return 0;
>
> -	return clocksource_register_hz(&clocksource_mfgpt, MFGPT_TICK_RATE);
> +	clocksource_register_hz(&clocksource_mfgpt, MFGPT_TICK_RATE);
> +	return 0;
>   }
>
>   arch_initcall(init_mfgpt_clocksource);
> diff --git a/arch/openrisc/kernel/time.c b/arch/openrisc/kernel/time.c
> index 7c52e94..3f789aa 100644
> --- a/arch/openrisc/kernel/time.c
> +++ b/arch/openrisc/kernel/time.c
> @@ -156,8 +156,7 @@ static struct clocksource openrisc_timer = {
>
>   static int __init openrisc_timer_init(void)
>   {
> -	if (clocksource_register_hz(&openrisc_timer, cpuinfo.clock_frequency))
> -		panic("failed to register clocksource");
> +	clocksource_register_hz(&openrisc_timer, cpuinfo.clock_frequency);
>
>   	/* Enable the incrementer: 'continuous' mode with interrupt disabled */
>   	mtspr(SPR_TTMR, SPR_TTMR_CR);
> diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
> index b3b1441..27c0627 100644
> --- a/arch/powerpc/kernel/time.c
> +++ b/arch/powerpc/kernel/time.c
> @@ -788,11 +788,7 @@ static void __init clocksource_init(void)
>   	else
>   		clock = &clocksource_timebase;
>
> -	if (clocksource_register_hz(clock, tb_ticks_per_sec)) {
> -		printk(KERN_ERR "clocksource: %s is already registered\n",
> -		       clock->name);
> -		return;
> -	}
> +	clocksource_register_hz(clock, tb_ticks_per_sec);
>
>   	printk(KERN_INFO "clocksource: %s mult[%x] shift[%d] registered\n",
>   	       clock->name, clock->mult, clock->shift);
> diff --git a/arch/um/kernel/time.c b/arch/um/kernel/time.c
> index 117568d..2034b58 100644
> --- a/arch/um/kernel/time.c
> +++ b/arch/um/kernel/time.c
> @@ -92,11 +92,7 @@ static void __init setup_itimer(void)
>   		clockevent_delta2ns(60 * HZ, &itimer_clockevent);
>   	itimer_clockevent.min_delta_ns =
>   		clockevent_delta2ns(1, &itimer_clockevent);
> -	err = clocksource_register_hz(&itimer_clocksource, USEC_PER_SEC);
> -	if (err) {
> -		printk(KERN_ERR "clocksource_register_hz returned %d\n", err);
> -		return;
> -	}
> +	clocksource_register_hz(&itimer_clocksource, USEC_PER_SEC);
>   	clockevents_register_device(&itimer_clockevent);
>   }
>
> diff --git a/arch/x86/platform/uv/uv_time.c b/arch/x86/platform/uv/uv_time.c
> index 5c86786..b963774 100644
> --- a/arch/x86/platform/uv/uv_time.c
> +++ b/arch/x86/platform/uv/uv_time.c
> @@ -379,15 +379,13 @@ static __init int uv_rtc_setup_clock(void)
>   	if (!is_uv_system())
>   		return -ENODEV;
>
> -	rc = clocksource_register_hz(&clocksource_uv, sn_rtc_cycles_per_second);
> -	if (rc)
> -		printk(KERN_INFO "UV RTC clocksource failed rc %d\n", rc);
> -	else
> -		printk(KERN_INFO "UV RTC clocksource registered freq %lu MHz\n",
> -			sn_rtc_cycles_per_second/(unsigned long)1E6);
> +	clocksource_register_hz(&clocksource_uv, sn_rtc_cycles_per_second);
> +
> +	pr_info("UV RTC clocksource registered freq %lu MHz\n",
> +		sn_rtc_cycles_per_second/(unsigned long)1E6);
>
> -	if (rc || !uv_rtc_evt_enable || x86_platform_ipi_callback)
> -		return rc;
> +	if (!uv_rtc_evt_enable || x86_platform_ipi_callback)
> +		return 0;
>
>   	/* Setup and register clockevents */
>   	rc = uv_rtc_allocate_timers();
> diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c
> index 6eab889..ab1dc63 100644
> --- a/drivers/clocksource/acpi_pm.c
> +++ b/drivers/clocksource/acpi_pm.c
> @@ -218,8 +218,9 @@ static int __init init_acpi_pm_clocksource(void)
>   		return -ENODEV;
>   	}
>
> -	return clocksource_register_hz(&clocksource_acpi_pm,
> +	clocksource_register_hz(&clocksource_acpi_pm,
>   						PMTMR_TICKS_PER_SEC);
> +	return 0;
>   }
>
>   /* We use fs_initcall because we want the PCI fixups to have run
> diff --git a/drivers/clocksource/cadence_ttc_timer.c b/drivers/clocksource/cadence_ttc_timer.c
> index 63f176d..b9b56ed 100644
> --- a/drivers/clocksource/cadence_ttc_timer.c
> +++ b/drivers/clocksource/cadence_ttc_timer.c
> @@ -301,11 +301,7 @@ static void __init ttc_setup_clocksource(struct clk *clk, void __iomem *base)
>   	__raw_writel(CNT_CNTRL_RESET,
>   		     ttccs->ttc.base_addr + TTC_CNT_CNTRL_OFFSET);
>
> -	err = clocksource_register_hz(&ttccs->cs, ttccs->ttc.freq / PRESCALE);
> -	if (WARN_ON(err)) {
> -		kfree(ttccs);
> -		return;
> -	}
> +	clocksource_register_hz(&ttccs->cs, ttccs->ttc.freq / PRESCALE);
>
>   	ttc_sched_clock_val_reg = base + TTC_COUNT_VAL_OFFSET;
>   	sched_clock_register(ttc_sched_clock_read, 16, ttccs->ttc.freq / PRESCALE);
> diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c
> index 62b0de6..98649c7 100644
> --- a/drivers/clocksource/exynos_mct.c
> +++ b/drivers/clocksource/exynos_mct.c
> @@ -193,9 +193,7 @@ struct clocksource mct_frc = {
>   static void __init exynos4_clocksource_init(void)
>   {
>   	exynos4_mct_frc_start(0, 0);
> -
> -	if (clocksource_register_hz(&mct_frc, clk_rate))
> -		panic("%s: can't register clocksource\n", mct_frc.name);
> +	clocksource_register_hz(&mct_frc, clk_rate);
>   }
>
>   static void exynos4_mct_comp0_stop(void)
> diff --git a/drivers/clocksource/i8253.c b/drivers/clocksource/i8253.c
> index 14ee3ef..9c45f0a 100644
> --- a/drivers/clocksource/i8253.c
> +++ b/drivers/clocksource/i8253.c
> @@ -95,7 +95,8 @@ static struct clocksource i8253_cs = {
>
>   int __init clocksource_i8253_init(void)
>   {
> -	return clocksource_register_hz(&i8253_cs, PIT_TICK_RATE);
> +	clocksource_register_hz(&i8253_cs, PIT_TICK_RATE);
> +	return 0;
>   }
>   #endif
>
> diff --git a/drivers/clocksource/mmio.c b/drivers/clocksource/mmio.c
> index c0e2512..6e0b530 100644
> --- a/drivers/clocksource/mmio.c
> +++ b/drivers/clocksource/mmio.c
> @@ -69,5 +69,6 @@ int __init clocksource_mmio_init(void __iomem *base, const char *name,
>   	cs->clksrc.mask = CLOCKSOURCE_MASK(bits);
>   	cs->clksrc.flags = CLOCK_SOURCE_IS_CONTINUOUS;
>
> -	return clocksource_register_hz(&cs->clksrc, hz);
> +	clocksource_register_hz(&cs->clksrc, hz);
> +	return 0;
>   }
> diff --git a/drivers/clocksource/samsung_pwm_timer.c b/drivers/clocksource/samsung_pwm_timer.c
> index 5645cfc..c59292f 100644
> --- a/drivers/clocksource/samsung_pwm_timer.c
> +++ b/drivers/clocksource/samsung_pwm_timer.c
> @@ -340,7 +340,6 @@ static void __init samsung_clocksource_init(void)
>   {
>   	unsigned long pclk;
>   	unsigned long clock_rate;
> -	int ret;
>
>   	pclk = clk_get_rate(pwm.timerclk);
>
> @@ -361,9 +360,7 @@ static void __init samsung_clocksource_init(void)
>   						pwm.variant.bits, clock_rate);
>
>   	samsung_clocksource.mask = CLOCKSOURCE_MASK(pwm.variant.bits);
> -	ret = clocksource_register_hz(&samsung_clocksource, clock_rate);
> -	if (ret)
> -		panic("samsung_clocksource_timer: can't register clocksource\n");
> +	clocksource_register_hz(&samsung_clocksource, clock_rate);
>   }
>
>   static void __init samsung_timer_resources(void)
> diff --git a/drivers/clocksource/scx200_hrt.c b/drivers/clocksource/scx200_hrt.c
> index 64f9e82..57bdc04 100644
> --- a/drivers/clocksource/scx200_hrt.c
> +++ b/drivers/clocksource/scx200_hrt.c
> @@ -83,7 +83,8 @@ static int __init init_hrt_clocksource(void)
>
>   	pr_info("enabling scx200 high-res timer (%s MHz +%d ppm)\n", mhz27 ? "27":"1", ppm);
>
> -	return clocksource_register_hz(&cs_hrt, freq);
> +	clocksource_register_hz(&cs_hrt, freq);
> +	return 0;
>   }
>
>   module_init(init_hrt_clocksource);
> diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
> index 00fdd11..805245d 100644
> --- a/drivers/clocksource/tcb_clksrc.c
> +++ b/drivers/clocksource/tcb_clksrc.c
> @@ -340,9 +340,7 @@ static int __init tcb_clksrc_init(void)
>   	}
>
>   	/* and away we go! */
> -	ret = clocksource_register_hz(&clksrc, divided_rate);
> -	if (ret)
> -		goto err_disable_t1;
> +	clocksource_register_hz(&clksrc, divided_rate);
>
>   	/* channel 2:  periodic and oneshot timer support */
>   	ret = setup_clkevents(tc, clk32k_divisor_idx);
> @@ -354,10 +352,6 @@ static int __init tcb_clksrc_init(void)
>   err_unregister_clksrc:
>   	clocksource_unregister(&clksrc);
>
> -err_disable_t1:
> -	if (!tc->tcb_config || tc->tcb_config->counter_width != 32)
> -		clk_disable_unprepare(tc->clk[1]);
> -
>   err_disable_t0:
>   	clk_disable_unprepare(t0_clk);
>
> diff --git a/drivers/clocksource/timer-marco.c b/drivers/clocksource/timer-marco.c
> index 09a17d9..ae78ce0 100644
> --- a/drivers/clocksource/timer-marco.c
> +++ b/drivers/clocksource/timer-marco.c
> @@ -283,7 +283,7 @@ static void __init sirfsoc_marco_timer_init(void)
>   	/* Clear all interrupts */
>   	writel_relaxed(0xFFFF, sirfsoc_timer_base + SIRFSOC_TIMER_INTR_STATUS);
>
> -	BUG_ON(clocksource_register_hz(&sirfsoc_clocksource, CLOCK_TICK_RATE));
> +	clocksource_register_hz(&sirfsoc_clocksource, CLOCK_TICK_RATE);
>
>   	sirfsoc_clockevent_init();
>   }
> diff --git a/drivers/clocksource/timer-prima2.c b/drivers/clocksource/timer-prima2.c
> index 8a492d3..c9cc307 100644
> --- a/drivers/clocksource/timer-prima2.c
> +++ b/drivers/clocksource/timer-prima2.c
> @@ -204,7 +204,7 @@ static void __init sirfsoc_prima2_timer_init(struct device_node *np)
>   	writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_HI);
>   	writel_relaxed(BIT(0), sirfsoc_timer_base + SIRFSOC_TIMER_STATUS);
>
> -	BUG_ON(clocksource_register_hz(&sirfsoc_clocksource, CLOCK_TICK_RATE));
> +	clocksource_register_hz(&sirfsoc_clocksource, CLOCK_TICK_RATE);
>
>   	sched_clock_register(sirfsoc_read_sched_clock, 64, CLOCK_TICK_RATE);
>
> diff --git a/drivers/clocksource/vt8500_timer.c b/drivers/clocksource/vt8500_timer.c
> index 1098ed3..13f5fa4 100644
> --- a/drivers/clocksource/vt8500_timer.c
> +++ b/drivers/clocksource/vt8500_timer.c
> @@ -150,9 +150,7 @@ static void __init vt8500_timer_init(struct device_node *np)
>   	writel(0xf, regbase + TIMER_STATUS_VAL);
>   	writel(~0, regbase + TIMER_MATCH_VAL);
>
> -	if (clocksource_register_hz(&clocksource, VT8500_TIMER_HZ))
> -		pr_err("%s: vt8500_timer_init: clocksource_register failed for %s\n",
> -					__func__, clocksource.name);
> +	clocksource_register_hz(&clocksource, VT8500_TIMER_HZ);
>
>   	clockevent.cpumask = cpumask_of(0);
>
> diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
> index 67301a4..5a17c5e 100644
> --- a/include/linux/clocksource.h
> +++ b/include/linux/clocksource.h
> @@ -282,7 +282,7 @@ static inline s64 clocksource_cyc2ns(cycle_t cycles, u32 mult, u32 shift)
>   }
>
>
> -extern int clocksource_register(struct clocksource*);
> +extern void clocksource_register(struct clocksource *);
>   extern int clocksource_unregister(struct clocksource*);
>   extern void clocksource_touch_watchdog(void);
>   extern struct clocksource* clocksource_get_next(void);
> @@ -301,17 +301,17 @@ clocks_calc_mult_shift(u32 *mult, u32 *shift, u32 from, u32 to, u32 minsec);
>    * Don't call __clocksource_register_scale directly, use
>    * clocksource_register_hz/khz
>    */
> -extern int
> +extern void
>   __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq);
>   extern void
>   __clocksource_updatefreq_scale(struct clocksource *cs, u32 scale, u32 freq);
>
> -static inline int clocksource_register_hz(struct clocksource *cs, u32 hz)
> +static inline void clocksource_register_hz(struct clocksource *cs, u32 hz)
>   {
>   	return __clocksource_register_scale(cs, 1, hz);
>   }
>
> -static inline int clocksource_register_khz(struct clocksource *cs, u32 khz)
> +static inline void clocksource_register_khz(struct clocksource *cs, u32 khz)
>   {
>   	return __clocksource_register_scale(cs, 1000, khz);
>   }
> diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
> index 9951575..686ff72 100644
> --- a/kernel/time/clocksource.c
> +++ b/kernel/time/clocksource.c
> @@ -782,7 +782,7 @@ EXPORT_SYMBOL_GPL(__clocksource_updatefreq_scale);
>    * This *SHOULD NOT* be called directly! Please use the
>    * clocksource_register_hz() or clocksource_register_khz helper functions.
>    */
> -int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq)
> +void __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq)
>   {
>
>   	/* Initialize mult/shift and max_idle_ns */
> @@ -794,7 +794,6 @@ int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq)
>   	clocksource_enqueue_watchdog(cs);
>   	clocksource_select();
>   	mutex_unlock(&clocksource_mutex);
> -	return 0;
>   }
>   EXPORT_SYMBOL_GPL(__clocksource_register_scale);
>
> @@ -804,7 +803,7 @@ EXPORT_SYMBOL_GPL(__clocksource_register_scale);
>    * @cs:		clocksource to be registered
>    *
>    */
> -int clocksource_register(struct clocksource *cs)
> +void clocksource_register(struct clocksource *cs)
>   {
>   	/* calculate max adjustment for given mult/shift */
>   	cs->maxadj = clocksource_max_adjustment(cs);
> @@ -820,7 +819,6 @@ int clocksource_register(struct clocksource *cs)
>   	clocksource_enqueue_watchdog(cs);
>   	clocksource_select();
>   	mutex_unlock(&clocksource_mutex);
> -	return 0;
>   }
>   EXPORT_SYMBOL(clocksource_register);
>
> diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c
> index 7a925ba..ae4c534 100644
> --- a/kernel/time/jiffies.c
> +++ b/kernel/time/jiffies.c
> @@ -88,7 +88,8 @@ EXPORT_SYMBOL(jiffies);
>
>   static int __init init_jiffies_clocksource(void)
>   {
> -	return clocksource_register(&clocksource_jiffies);
> +	clocksource_register(&clocksource_jiffies);
> +	return 0;
>   }
>
>   core_initcall(init_jiffies_clocksource);
>


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[PATCH 2/2] clocksource: Make clocksource register functions void

[Yijing Wang]

On 2014/1/23 16:40, Daniel Lezcano wrote:
> On 01/23/2014 08:12 AM, Yijing Wang wrote:
>> Currently, clocksource_register() and __clocksource_register_scale()
>> functions always return 0, it's pointless, make functions void.
>> And remove the dead code that check the clocksource_register_hz()
>> return value.
>>
>> Signed-off-by: Yijing Wang <wangyijing@huawei.com>
> 
> Well, do we really want to change all these files to not take care of a return value ? What about is we have to check it again later ?
> 
> I would recommend to investigate __clocksource_register_scale and the underneath functions if there is not an error to be returned in the call stack somewhere which is ignored today.
> 
> The same applies for clocksource_register.

Hi Daniel, thanks for your comment, all functions type under __clocksource_register_scale() are void.
This just is trivial cleanup patch, I don't know whether we will check these function return value again later.
If there is some possibility to check it again, I agree to keep them. Of course, this is all determined by Thomas.

Thanks!
Yijing.

> 
>> ---
>>   arch/arm/mach-davinci/time.c                    |    5 ++---
>>   arch/arm/mach-msm/timer.c                       |    4 +---
>>   arch/arm/mach-omap2/timer.c                     |    8 +++-----
>>   arch/avr32/kernel/time.c                        |    4 +---
>>   arch/blackfin/kernel/time-ts.c                  |    6 ++----
>>   arch/microblaze/kernel/timer.c                  |    3 +--
>>   arch/mips/jz4740/time.c                         |    6 +-----
>>   arch/mips/loongson/common/cs5536/cs5536_mfgpt.c |    3 ++-
>>   arch/openrisc/kernel/time.c                     |    3 +--
>>   arch/powerpc/kernel/time.c                      |    6 +-----
>>   arch/um/kernel/time.c                           |    6 +-----
>>   arch/x86/platform/uv/uv_time.c                  |   14 ++++++--------
>>   drivers/clocksource/acpi_pm.c                   |    3 ++-
>>   drivers/clocksource/cadence_ttc_timer.c         |    6 +-----
>>   drivers/clocksource/exynos_mct.c                |    4 +---
>>   drivers/clocksource/i8253.c                     |    3 ++-
>>   drivers/clocksource/mmio.c                      |    3 ++-
>>   drivers/clocksource/samsung_pwm_timer.c         |    5 +----
>>   drivers/clocksource/scx200_hrt.c                |    3 ++-
>>   drivers/clocksource/tcb_clksrc.c                |    8 +-------
>>   drivers/clocksource/timer-marco.c               |    2 +-
>>   drivers/clocksource/timer-prima2.c              |    2 +-
>>   drivers/clocksource/vt8500_timer.c              |    4 +---
>>   include/linux/clocksource.h                     |    8 ++++----
>>   kernel/time/clocksource.c                       |    6 ++----
>>   kernel/time/jiffies.c                           |    3 ++-
>>   26 files changed, 45 insertions(+), 83 deletions(-)
>>
>> diff --git a/arch/arm/mach-davinci/time.c b/arch/arm/mach-davinci/time.c
>> index 56c6eb5..9536f85 100644
>> --- a/arch/arm/mach-davinci/time.c
>> +++ b/arch/arm/mach-davinci/time.c
>> @@ -387,9 +387,8 @@ void __init davinci_timer_init(void)
>>
>>       /* setup clocksource */
>>       clocksource_davinci.name = id_to_name[clocksource_id];
>> -    if (clocksource_register_hz(&clocksource_davinci,
>> -                    davinci_clock_tick_rate))
>> -        printk(err, clocksource_davinci.name);
>> +    clocksource_register_hz(&clocksource_davinci,
>> +                    davinci_clock_tick_rate);
>>
>>       setup_sched_clock(davinci_read_sched_clock, 32,
>>                 davinci_clock_tick_rate);
>> diff --git a/arch/arm/mach-msm/timer.c b/arch/arm/mach-msm/timer.c
>> index 1e9c338..c96e034 100644
>> --- a/arch/arm/mach-msm/timer.c
>> +++ b/arch/arm/mach-msm/timer.c
>> @@ -226,9 +226,7 @@ static void __init msm_timer_init(u32 dgt_hz, int sched_bits, int irq,
>>
>>   err:
>>       writel_relaxed(TIMER_ENABLE_EN, source_base + TIMER_ENABLE);
>> -    res = clocksource_register_hz(cs, dgt_hz);
>> -    if (res)
>> -        pr_err("clocksource_register failed\n");
>> +    clocksource_register_hz(cs, dgt_hz);
>>       setup_sched_clock(msm_sched_clock_read, sched_bits, dgt_hz);
>>   }
>>
>> diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c
>> index 3ca81e0..beaf7c7 100644
>> --- a/arch/arm/mach-omap2/timer.c
>> +++ b/arch/arm/mach-omap2/timer.c
>> @@ -473,11 +473,9 @@ static void __init omap2_gptimer_clocksource_init(int gptimer_id,
>>                      OMAP_TIMER_NONPOSTED);
>>       setup_sched_clock(dmtimer_read_sched_clock, 32, clksrc.rate);
>>
>> -    if (clocksource_register_hz(&clocksource_gpt, clksrc.rate))
>> -        pr_err("Could not register clocksource %s\n",
>> -            clocksource_gpt.name);
>> -    else
>> -        pr_info("OMAP clocksource: %s at %lu Hz\n",
>> +    clocksource_register_hz(&clocksource_gpt, clksrc.rate);
>> +
>> +    pr_info("OMAP clocksource: %s at %lu Hz\n",
>>               clocksource_gpt.name, clksrc.rate);
>>   }
>>
>> diff --git a/arch/avr32/kernel/time.c b/arch/avr32/kernel/time.c
>> index d0f771b..51b4a66 100644
>> --- a/arch/avr32/kernel/time.c
>> +++ b/arch/avr32/kernel/time.c
>> @@ -134,9 +134,7 @@ void __init time_init(void)
>>
>>       /* figure rate for counter */
>>       counter_hz = clk_get_rate(boot_cpu_data.clk);
>> -    ret = clocksource_register_hz(&counter, counter_hz);
>> -    if (ret)
>> -        pr_debug("timer: could not register clocksource: %d\n", ret);
>> +    clocksource_register_hz(&counter, counter_hz);
>>
>>       /* setup COMPARE clockevent */
>>       comparator.mult = div_sc(counter_hz, NSEC_PER_SEC, comparator.shift);
>> diff --git a/arch/blackfin/kernel/time-ts.c b/arch/blackfin/kernel/time-ts.c
>> index cb0a484..df3bb08 100644
>> --- a/arch/blackfin/kernel/time-ts.c
>> +++ b/arch/blackfin/kernel/time-ts.c
>> @@ -51,8 +51,7 @@ static inline unsigned long long bfin_cs_cycles_sched_clock(void)
>>
>>   static int __init bfin_cs_cycles_init(void)
>>   {
>> -    if (clocksource_register_hz(&bfin_cs_cycles, get_cclk()))
>> -        panic("failed to register clocksource");
>> +    clocksource_register_hz(&bfin_cs_cycles, get_cclk());
>>
>>       return 0;
>>   }
>> @@ -103,8 +102,7 @@ static int __init bfin_cs_gptimer0_init(void)
>>   {
>>       setup_gptimer0();
>>
>> -    if (clocksource_register_hz(&bfin_cs_gptimer0, get_sclk()))
>> -        panic("failed to register clocksource");
>> +    clocksource_register_hz(&bfin_cs_gptimer0, get_sclk());
>>
>>       return 0;
>>   }
>> diff --git a/arch/microblaze/kernel/timer.c b/arch/microblaze/kernel/timer.c
>> index 3e39b10..6a2417e 100644
>> --- a/arch/microblaze/kernel/timer.c
>> +++ b/arch/microblaze/kernel/timer.c
>> @@ -208,8 +208,7 @@ static struct clocksource clocksource_microblaze = {
>>
>>   static int __init xilinx_clocksource_init(void)
>>   {
>> -    if (clocksource_register_hz(&clocksource_microblaze, timer_clock_freq))
>> -        panic("failed to register clocksource");
>> +    clocksource_register_hz(&clocksource_microblaze, timer_clock_freq);
>>
>>       /* stop timer1 */
>>       out_be32(timer_baseaddr + TCSR1,
>> diff --git a/arch/mips/jz4740/time.c b/arch/mips/jz4740/time.c
>> index 5e430ce..041cdff 100644
>> --- a/arch/mips/jz4740/time.c
>> +++ b/arch/mips/jz4740/time.c
>> @@ -105,7 +105,6 @@ static struct irqaction timer_irqaction = {
>>
>>   void __init plat_time_init(void)
>>   {
>> -    int ret;
>>       uint32_t clk_rate;
>>       uint16_t ctrl;
>>
>> @@ -121,10 +120,7 @@ void __init plat_time_init(void)
>>
>>       clockevents_register_device(&jz4740_clockevent);
>>
>> -    ret = clocksource_register_hz(&jz4740_clocksource, clk_rate);
>> -
>> -    if (ret)
>> -        printk(KERN_ERR "Failed to register clocksource: %d\n", ret);
>> +    clocksource_register_hz(&jz4740_clocksource, clk_rate);
>>
>>       setup_irq(JZ4740_IRQ_TCU0, &timer_irqaction);
>>
>> diff --git a/arch/mips/loongson/common/cs5536/cs5536_mfgpt.c b/arch/mips/loongson/common/cs5536/cs5536_mfgpt.c
>> index c639b9d..9fa6d99 100644
>> --- a/arch/mips/loongson/common/cs5536/cs5536_mfgpt.c
>> +++ b/arch/mips/loongson/common/cs5536/cs5536_mfgpt.c
>> @@ -208,7 +208,8 @@ int __init init_mfgpt_clocksource(void)
>>       if (num_possible_cpus() > 1)    /* MFGPT does not scale! */
>>           return 0;
>>
>> -    return clocksource_register_hz(&clocksource_mfgpt, MFGPT_TICK_RATE);
>> +    clocksource_register_hz(&clocksource_mfgpt, MFGPT_TICK_RATE);
>> +    return 0;
>>   }
>>
>>   arch_initcall(init_mfgpt_clocksource);
>> diff --git a/arch/openrisc/kernel/time.c b/arch/openrisc/kernel/time.c
>> index 7c52e94..3f789aa 100644
>> --- a/arch/openrisc/kernel/time.c
>> +++ b/arch/openrisc/kernel/time.c
>> @@ -156,8 +156,7 @@ static struct clocksource openrisc_timer = {
>>
>>   static int __init openrisc_timer_init(void)
>>   {
>> -    if (clocksource_register_hz(&openrisc_timer, cpuinfo.clock_frequency))
>> -        panic("failed to register clocksource");
>> +    clocksource_register_hz(&openrisc_timer, cpuinfo.clock_frequency);
>>
>>       /* Enable the incrementer: 'continuous' mode with interrupt disabled */
>>       mtspr(SPR_TTMR, SPR_TTMR_CR);
>> diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
>> index b3b1441..27c0627 100644
>> --- a/arch/powerpc/kernel/time.c
>> +++ b/arch/powerpc/kernel/time.c
>> @@ -788,11 +788,7 @@ static void __init clocksource_init(void)
>>       else
>>           clock = &clocksource_timebase;
>>
>> -    if (clocksource_register_hz(clock, tb_ticks_per_sec)) {
>> -        printk(KERN_ERR "clocksource: %s is already registered\n",
>> -               clock->name);
>> -        return;
>> -    }
>> +    clocksource_register_hz(clock, tb_ticks_per_sec);
>>
>>       printk(KERN_INFO "clocksource: %s mult[%x] shift[%d] registered\n",
>>              clock->name, clock->mult, clock->shift);
>> diff --git a/arch/um/kernel/time.c b/arch/um/kernel/time.c
>> index 117568d..2034b58 100644
>> --- a/arch/um/kernel/time.c
>> +++ b/arch/um/kernel/time.c
>> @@ -92,11 +92,7 @@ static void __init setup_itimer(void)
>>           clockevent_delta2ns(60 * HZ, &itimer_clockevent);
>>       itimer_clockevent.min_delta_ns =
>>           clockevent_delta2ns(1, &itimer_clockevent);
>> -    err = clocksource_register_hz(&itimer_clocksource, USEC_PER_SEC);
>> -    if (err) {
>> -        printk(KERN_ERR "clocksource_register_hz returned %d\n", err);
>> -        return;
>> -    }
>> +    clocksource_register_hz(&itimer_clocksource, USEC_PER_SEC);
>>       clockevents_register_device(&itimer_clockevent);
>>   }
>>
>> diff --git a/arch/x86/platform/uv/uv_time.c b/arch/x86/platform/uv/uv_time.c
>> index 5c86786..b963774 100644
>> --- a/arch/x86/platform/uv/uv_time.c
>> +++ b/arch/x86/platform/uv/uv_time.c
>> @@ -379,15 +379,13 @@ static __init int uv_rtc_setup_clock(void)
>>       if (!is_uv_system())
>>           return -ENODEV;
>>
>> -    rc = clocksource_register_hz(&clocksource_uv, sn_rtc_cycles_per_second);
>> -    if (rc)
>> -        printk(KERN_INFO "UV RTC clocksource failed rc %d\n", rc);
>> -    else
>> -        printk(KERN_INFO "UV RTC clocksource registered freq %lu MHz\n",
>> -            sn_rtc_cycles_per_second/(unsigned long)1E6);
>> +    clocksource_register_hz(&clocksource_uv, sn_rtc_cycles_per_second);
>> +
>> +    pr_info("UV RTC clocksource registered freq %lu MHz\n",
>> +        sn_rtc_cycles_per_second/(unsigned long)1E6);
>>
>> -    if (rc || !uv_rtc_evt_enable || x86_platform_ipi_callback)
>> -        return rc;
>> +    if (!uv_rtc_evt_enable || x86_platform_ipi_callback)
>> +        return 0;
>>
>>       /* Setup and register clockevents */
>>       rc = uv_rtc_allocate_timers();
>> diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c
>> index 6eab889..ab1dc63 100644
>> --- a/drivers/clocksource/acpi_pm.c
>> +++ b/drivers/clocksource/acpi_pm.c
>> @@ -218,8 +218,9 @@ static int __init init_acpi_pm_clocksource(void)
>>           return -ENODEV;
>>       }
>>
>> -    return clocksource_register_hz(&clocksource_acpi_pm,
>> +    clocksource_register_hz(&clocksource_acpi_pm,
>>                           PMTMR_TICKS_PER_SEC);
>> +    return 0;
>>   }
>>
>>   /* We use fs_initcall because we want the PCI fixups to have run
>> diff --git a/drivers/clocksource/cadence_ttc_timer.c b/drivers/clocksource/cadence_ttc_timer.c
>> index 63f176d..b9b56ed 100644
>> --- a/drivers/clocksource/cadence_ttc_timer.c
>> +++ b/drivers/clocksource/cadence_ttc_timer.c
>> @@ -301,11 +301,7 @@ static void __init ttc_setup_clocksource(struct clk *clk, void __iomem *base)
>>       __raw_writel(CNT_CNTRL_RESET,
>>                ttccs->ttc.base_addr + TTC_CNT_CNTRL_OFFSET);
>>
>> -    err = clocksource_register_hz(&ttccs->cs, ttccs->ttc.freq / PRESCALE);
>> -    if (WARN_ON(err)) {
>> -        kfree(ttccs);
>> -        return;
>> -    }
>> +    clocksource_register_hz(&ttccs->cs, ttccs->ttc.freq / PRESCALE);
>>
>>       ttc_sched_clock_val_reg = base + TTC_COUNT_VAL_OFFSET;
>>       sched_clock_register(ttc_sched_clock_read, 16, ttccs->ttc.freq / PRESCALE);
>> diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c
>> index 62b0de6..98649c7 100644
>> --- a/drivers/clocksource/exynos_mct.c
>> +++ b/drivers/clocksource/exynos_mct.c
>> @@ -193,9 +193,7 @@ struct clocksource mct_frc = {
>>   static void __init exynos4_clocksource_init(void)
>>   {
>>       exynos4_mct_frc_start(0, 0);
>> -
>> -    if (clocksource_register_hz(&mct_frc, clk_rate))
>> -        panic("%s: can't register clocksource\n", mct_frc.name);
>> +    clocksource_register_hz(&mct_frc, clk_rate);
>>   }
>>
>>   static void exynos4_mct_comp0_stop(void)
>> diff --git a/drivers/clocksource/i8253.c b/drivers/clocksource/i8253.c
>> index 14ee3ef..9c45f0a 100644
>> --- a/drivers/clocksource/i8253.c
>> +++ b/drivers/clocksource/i8253.c
>> @@ -95,7 +95,8 @@ static struct clocksource i8253_cs = {
>>
>>   int __init clocksource_i8253_init(void)
>>   {
>> -    return clocksource_register_hz(&i8253_cs, PIT_TICK_RATE);
>> +    clocksource_register_hz(&i8253_cs, PIT_TICK_RATE);
>> +    return 0;
>>   }
>>   #endif
>>
>> diff --git a/drivers/clocksource/mmio.c b/drivers/clocksource/mmio.c
>> index c0e2512..6e0b530 100644
>> --- a/drivers/clocksource/mmio.c
>> +++ b/drivers/clocksource/mmio.c
>> @@ -69,5 +69,6 @@ int __init clocksource_mmio_init(void __iomem *base, const char *name,
>>       cs->clksrc.mask = CLOCKSOURCE_MASK(bits);
>>       cs->clksrc.flags = CLOCK_SOURCE_IS_CONTINUOUS;
>>
>> -    return clocksource_register_hz(&cs->clksrc, hz);
>> +    clocksource_register_hz(&cs->clksrc, hz);
>> +    return 0;
>>   }
>> diff --git a/drivers/clocksource/samsung_pwm_timer.c b/drivers/clocksource/samsung_pwm_timer.c
>> index 5645cfc..c59292f 100644
>> --- a/drivers/clocksource/samsung_pwm_timer.c
>> +++ b/drivers/clocksource/samsung_pwm_timer.c
>> @@ -340,7 +340,6 @@ static void __init samsung_clocksource_init(void)
>>   {
>>       unsigned long pclk;
>>       unsigned long clock_rate;
>> -    int ret;
>>
>>       pclk = clk_get_rate(pwm.timerclk);
>>
>> @@ -361,9 +360,7 @@ static void __init samsung_clocksource_init(void)
>>                           pwm.variant.bits, clock_rate);
>>
>>       samsung_clocksource.mask = CLOCKSOURCE_MASK(pwm.variant.bits);
>> -    ret = clocksource_register_hz(&samsung_clocksource, clock_rate);
>> -    if (ret)
>> -        panic("samsung_clocksource_timer: can't register clocksource\n");
>> +    clocksource_register_hz(&samsung_clocksource, clock_rate);
>>   }
>>
>>   static void __init samsung_timer_resources(void)
>> diff --git a/drivers/clocksource/scx200_hrt.c b/drivers/clocksource/scx200_hrt.c
>> index 64f9e82..57bdc04 100644
>> --- a/drivers/clocksource/scx200_hrt.c
>> +++ b/drivers/clocksource/scx200_hrt.c
>> @@ -83,7 +83,8 @@ static int __init init_hrt_clocksource(void)
>>
>>       pr_info("enabling scx200 high-res timer (%s MHz +%d ppm)\n", mhz27 ? "27":"1", ppm);
>>
>> -    return clocksource_register_hz(&cs_hrt, freq);
>> +    clocksource_register_hz(&cs_hrt, freq);
>> +    return 0;
>>   }
>>
>>   module_init(init_hrt_clocksource);
>> diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
>> index 00fdd11..805245d 100644
>> --- a/drivers/clocksource/tcb_clksrc.c
>> +++ b/drivers/clocksource/tcb_clksrc.c
>> @@ -340,9 +340,7 @@ static int __init tcb_clksrc_init(void)
>>       }
>>
>>       /* and away we go! */
>> -    ret = clocksource_register_hz(&clksrc, divided_rate);
>> -    if (ret)
>> -        goto err_disable_t1;
>> +    clocksource_register_hz(&clksrc, divided_rate);
>>
>>       /* channel 2:  periodic and oneshot timer support */
>>       ret = setup_clkevents(tc, clk32k_divisor_idx);
>> @@ -354,10 +352,6 @@ static int __init tcb_clksrc_init(void)
>>   err_unregister_clksrc:
>>       clocksource_unregister(&clksrc);
>>
>> -err_disable_t1:
>> -    if (!tc->tcb_config || tc->tcb_config->counter_width != 32)
>> -        clk_disable_unprepare(tc->clk[1]);
>> -
>>   err_disable_t0:
>>       clk_disable_unprepare(t0_clk);
>>
>> diff --git a/drivers/clocksource/timer-marco.c b/drivers/clocksource/timer-marco.c
>> index 09a17d9..ae78ce0 100644
>> --- a/drivers/clocksource/timer-marco.c
>> +++ b/drivers/clocksource/timer-marco.c
>> @@ -283,7 +283,7 @@ static void __init sirfsoc_marco_timer_init(void)
>>       /* Clear all interrupts */
>>       writel_relaxed(0xFFFF, sirfsoc_timer_base + SIRFSOC_TIMER_INTR_STATUS);
>>
>> -    BUG_ON(clocksource_register_hz(&sirfsoc_clocksource, CLOCK_TICK_RATE));
>> +    clocksource_register_hz(&sirfsoc_clocksource, CLOCK_TICK_RATE);
>>
>>       sirfsoc_clockevent_init();
>>   }
>> diff --git a/drivers/clocksource/timer-prima2.c b/drivers/clocksource/timer-prima2.c
>> index 8a492d3..c9cc307 100644
>> --- a/drivers/clocksource/timer-prima2.c
>> +++ b/drivers/clocksource/timer-prima2.c
>> @@ -204,7 +204,7 @@ static void __init sirfsoc_prima2_timer_init(struct device_node *np)
>>       writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_HI);
>>       writel_relaxed(BIT(0), sirfsoc_timer_base + SIRFSOC_TIMER_STATUS);
>>
>> -    BUG_ON(clocksource_register_hz(&sirfsoc_clocksource, CLOCK_TICK_RATE));
>> +    clocksource_register_hz(&sirfsoc_clocksource, CLOCK_TICK_RATE);
>>
>>       sched_clock_register(sirfsoc_read_sched_clock, 64, CLOCK_TICK_RATE);
>>
>> diff --git a/drivers/clocksource/vt8500_timer.c b/drivers/clocksource/vt8500_timer.c
>> index 1098ed3..13f5fa4 100644
>> --- a/drivers/clocksource/vt8500_timer.c
>> +++ b/drivers/clocksource/vt8500_timer.c
>> @@ -150,9 +150,7 @@ static void __init vt8500_timer_init(struct device_node *np)
>>       writel(0xf, regbase + TIMER_STATUS_VAL);
>>       writel(~0, regbase + TIMER_MATCH_VAL);
>>
>> -    if (clocksource_register_hz(&clocksource, VT8500_TIMER_HZ))
>> -        pr_err("%s: vt8500_timer_init: clocksource_register failed for %s\n",
>> -                    __func__, clocksource.name);
>> +    clocksource_register_hz(&clocksource, VT8500_TIMER_HZ);
>>
>>       clockevent.cpumask = cpumask_of(0);
>>
>> diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
>> index 67301a4..5a17c5e 100644
>> --- a/include/linux/clocksource.h
>> +++ b/include/linux/clocksource.h
>> @@ -282,7 +282,7 @@ static inline s64 clocksource_cyc2ns(cycle_t cycles, u32 mult, u32 shift)
>>   }
>>
>>
>> -extern int clocksource_register(struct clocksource*);
>> +extern void clocksource_register(struct clocksource *);
>>   extern int clocksource_unregister(struct clocksource*);
>>   extern void clocksource_touch_watchdog(void);
>>   extern struct clocksource* clocksource_get_next(void);
>> @@ -301,17 +301,17 @@ clocks_calc_mult_shift(u32 *mult, u32 *shift, u32 from, u32 to, u32 minsec);
>>    * Don't call __clocksource_register_scale directly, use
>>    * clocksource_register_hz/khz
>>    */
>> -extern int
>> +extern void
>>   __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq);
>>   extern void
>>   __clocksource_updatefreq_scale(struct clocksource *cs, u32 scale, u32 freq);
>>
>> -static inline int clocksource_register_hz(struct clocksource *cs, u32 hz)
>> +static inline void clocksource_register_hz(struct clocksource *cs, u32 hz)
>>   {
>>       return __clocksource_register_scale(cs, 1, hz);
>>   }
>>
>> -static inline int clocksource_register_khz(struct clocksource *cs, u32 khz)
>> +static inline void clocksource_register_khz(struct clocksource *cs, u32 khz)
>>   {
>>       return __clocksource_register_scale(cs, 1000, khz);
>>   }
>> diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
>> index 9951575..686ff72 100644
>> --- a/kernel/time/clocksource.c
>> +++ b/kernel/time/clocksource.c
>> @@ -782,7 +782,7 @@ EXPORT_SYMBOL_GPL(__clocksource_updatefreq_scale);
>>    * This *SHOULD NOT* be called directly! Please use the
>>    * clocksource_register_hz() or clocksource_register_khz helper functions.
>>    */
>> -int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq)
>> +void __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq)
>>   {
>>
>>       /* Initialize mult/shift and max_idle_ns */
>> @@ -794,7 +794,6 @@ int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq)
>>       clocksource_enqueue_watchdog(cs);
>>       clocksource_select();
>>       mutex_unlock(&clocksource_mutex);
>> -    return 0;
>>   }
>>   EXPORT_SYMBOL_GPL(__clocksource_register_scale);
>>
>> @@ -804,7 +803,7 @@ EXPORT_SYMBOL_GPL(__clocksource_register_scale);
>>    * @cs:        clocksource to be registered
>>    *
>>    */
>> -int clocksource_register(struct clocksource *cs)
>> +void clocksource_register(struct clocksource *cs)
>>   {
>>       /* calculate max adjustment for given mult/shift */
>>       cs->maxadj = clocksource_max_adjustment(cs);
>> @@ -820,7 +819,6 @@ int clocksource_register(struct clocksource *cs)
>>       clocksource_enqueue_watchdog(cs);
>>       clocksource_select();
>>       mutex_unlock(&clocksource_mutex);
>> -    return 0;
>>   }
>>   EXPORT_SYMBOL(clocksource_register);
>>
>> diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c
>> index 7a925ba..ae4c534 100644
>> --- a/kernel/time/jiffies.c
>> +++ b/kernel/time/jiffies.c
>> @@ -88,7 +88,8 @@ EXPORT_SYMBOL(jiffies);
>>
>>   static int __init init_jiffies_clocksource(void)
>>   {
>> -    return clocksource_register(&clocksource_jiffies);
>> +    clocksource_register(&clocksource_jiffies);
>> +    return 0;
>>   }
>>
>>   core_initcall(init_jiffies_clocksource);
>>
> 
> 


-- 
Thanks!
Yijing

[PATCH 2/2] clocksource: Make clocksource register functions void

[Thomas Gleixner]

On Thu, 23 Jan 2014, Daniel Lezcano wrote:
> On 01/23/2014 08:12 AM, Yijing Wang wrote:
> > Currently, clocksource_register() and __clocksource_register_scale()
> > functions always return 0, it's pointless, make functions void.
> > And remove the dead code that check the clocksource_register_hz()
> > return value.
> > 
> > Signed-off-by: Yijing Wang <wangyijing@huawei.com>
> 
> Well, do we really want to change all these files to not take care of a return
> value ? What about is we have to check it again later ?
> 
> I would recommend to investigate __clocksource_register_scale and the
> underneath functions if there is not an error to be returned in the call stack
> somewhere which is ignored today.
> 
> The same applies for clocksource_register.

There is really no point in making it fail. It's so low level that
anything more than a proper printk/BUG/WARN is overkill.

Thanks,

	tglx