From 0e62fd836e4c2908cc1e32c68806529b4f859955 Mon Sep 17 00:00:00 2001 From: Gregory CLEMENT Date: Wed, 17 Aug 2016 12:21:33 +0200 Subject: [PATCH 1/3] clocksource/drivers/time-armada-370-xp: Fix the clock reference While converting the init function to return an error, the wrong clock was get. This leads to the wrong clock rate and slows down the kernel. For example, it affects typical boot time: - without fix: over 1 minute - with fix: 15 seconds Tested-by: Stefan Roese Tested-by: Ralph Sennhauser Signed-off-by: Gregory CLEMENT Signed-off-by: Daniel Lezcano Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Fixes: 12549e27c63c ("clocksource/drivers/time-armada-370-xp: Convert init function to return error") Link: http://lkml.kernel.org/r/1471429296-9053-1-git-send-email-daniel.lezcano@linaro.org [ Refined the changelog. ] Signed-off-by: Ingo Molnar --- drivers/clocksource/time-armada-370-xp.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/clocksource/time-armada-370-xp.c b/drivers/clocksource/time-armada-370-xp.c index 719b478d136e..3c39e6f45971 100644 --- a/drivers/clocksource/time-armada-370-xp.c +++ b/drivers/clocksource/time-armada-370-xp.c @@ -338,7 +338,6 @@ static int __init armada_xp_timer_init(struct device_node *np) struct clk *clk = of_clk_get_by_name(np, "fixed"); int ret; - clk = of_clk_get(np, 0); if (IS_ERR(clk)) { pr_err("Failed to get clock"); return PTR_ERR(clk); From 16c8eba0fe01e03317f48868105103a8f5938e85 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Wed, 17 Aug 2016 12:21:34 +0200 Subject: [PATCH 2/3] clocksource/drivers/kona: Fix get_counter() error handling I could not figure out why, but GCC cannot prove that the kona_timer_init() function always initializes its two outputs, and we get a warning for the use of the 'lsw' variable later, which is obviously correct. drivers/clocksource/bcm_kona_timer.c: In function 'kona_timer_init': drivers/clocksource/bcm_kona_timer.c:119:13: error: 'lsw' may be used uninitialized in this function [-Werror=maybe-uninitialized] Slightly reordering the loop makes the warning disappear, after it becomes more obvious to the compiler that the loop is always entered on the first iteration. As pointed out by Ray Jui, there is a related problem in the way we deal with the loop running into the limit, as we just keep going there with an invalid counter data, so instead we now propagate a -ETIMEDOUT result to the caller. Signed-off-by: Arnd Bergmann Signed-off-by: Daniel Lezcano Acked-by: Ray Jui Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: bcm-kernel-feedback-list@broadcom.com Link: http://lkml.kernel.org/r/1471429296-9053-2-git-send-email-daniel.lezcano@linaro.org Link: https://patchwork.kernel.org/patch/9174261/ Signed-off-by: Ingo Molnar --- drivers/clocksource/bcm_kona_timer.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/drivers/clocksource/bcm_kona_timer.c b/drivers/clocksource/bcm_kona_timer.c index 7e3fd375a627..92f6e4deee74 100644 --- a/drivers/clocksource/bcm_kona_timer.c +++ b/drivers/clocksource/bcm_kona_timer.c @@ -66,10 +66,10 @@ static void kona_timer_disable_and_clear(void __iomem *base) } -static void +static int kona_timer_get_counter(void __iomem *timer_base, uint32_t *msw, uint32_t *lsw) { - int loop_limit = 4; + int loop_limit = 3; /* * Read 64-bit free running counter @@ -83,18 +83,19 @@ kona_timer_get_counter(void __iomem *timer_base, uint32_t *msw, uint32_t *lsw) * if new hi-word is equal to previously read hi-word then stop. */ - while (--loop_limit) { + do { *msw = readl(timer_base + KONA_GPTIMER_STCHI_OFFSET); *lsw = readl(timer_base + KONA_GPTIMER_STCLO_OFFSET); if (*msw == readl(timer_base + KONA_GPTIMER_STCHI_OFFSET)) break; - } + } while (--loop_limit); if (!loop_limit) { pr_err("bcm_kona_timer: getting counter failed.\n"); pr_err(" Timer will be impacted\n"); + return -ETIMEDOUT; } - return; + return 0; } static int kona_timer_set_next_event(unsigned long clc, @@ -112,8 +113,11 @@ static int kona_timer_set_next_event(unsigned long clc, uint32_t lsw, msw; uint32_t reg; + int ret; - kona_timer_get_counter(timers.tmr_regs, &msw, &lsw); + ret = kona_timer_get_counter(timers.tmr_regs, &msw, &lsw); + if (ret) + return ret; /* Load the "next" event tick value */ writel(lsw + clc, timers.tmr_regs + KONA_GPTIMER_STCM0_OFFSET); From be5769e2061ac40b32daa83e28e1c4aac7133511 Mon Sep 17 00:00:00 2001 From: Paul Gortmaker Date: Wed, 17 Aug 2016 12:21:35 +0200 Subject: [PATCH 3/3] clocksource/drivers/mips-gic-timer: Make gic_clocksource_of_init() return int In commit: d8152bf85d2c0 ("clocksource/drivers/mips-gic-timer: Convert init function to return error") several return values were added to a void function resulting in the following warnings: clocksource/mips-gic-timer.c: In function 'gic_clocksource_of_init': clocksource/mips-gic-timer.c:175:3: warning: 'return' with a value, in function returning void [enabled by default] clocksource/mips-gic-timer.c:183:4: warning: 'return' with a value, in function returning void [enabled by default] clocksource/mips-gic-timer.c:190:3: warning: 'return' with a value, in function returning void [enabled by default] clocksource/mips-gic-timer.c:195:3: warning: 'return' with a value, in function returning void [enabled by default] clocksource/mips-gic-timer.c:200:3: warning: 'return' with a value, in function returning void [enabled by default] clocksource/mips-gic-timer.c:211:2: warning: 'return' with a value, in function returning void [enabled by default] clocksource/mips-gic-timer.c: At top level: clocksource/mips-gic-timer.c:213:1: warning: comparison of distinct pointer types lacks a cast [enabled by default] clocksource/mips-gic-timer.c: In function 'gic_clocksource_of_init': clocksource/mips-gic-timer.c:183:18: warning: ignoring return value of 'PTR_ERR', declared with attribute warn_unused_result [-Wunused-result] Given that the addition of the return values was intentional, it seems that the conversion of the containing function from void to int was simply overlooked. Signed-off-by: Paul Gortmaker Signed-off-by: Daniel Lezcano Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-mips@linux-mips.org Fixes: d8152bf85d2c ("clocksource/drivers/mips-gic-timer: Convert init function to return error") Link: http://lkml.kernel.org/r/1471429296-9053-3-git-send-email-daniel.lezcano@linaro.org Signed-off-by: Ingo Molnar --- drivers/clocksource/mips-gic-timer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/clocksource/mips-gic-timer.c b/drivers/clocksource/mips-gic-timer.c index d91e8725917c..b4b3ab5a11ad 100644 --- a/drivers/clocksource/mips-gic-timer.c +++ b/drivers/clocksource/mips-gic-timer.c @@ -164,7 +164,7 @@ void __init gic_clocksource_init(unsigned int frequency) gic_start_count(); } -static void __init gic_clocksource_of_init(struct device_node *node) +static int __init gic_clocksource_of_init(struct device_node *node) { struct clk *clk; int ret;