From 0b9a29add43273e64ef45472e08d38116fee1d82 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Sun, 24 Apr 2016 14:30:16 -0700 Subject: arm: Use _rcuidle tracepoint to allow use from idle Testing on ARM encountered the following pair of lockdep-RCU splats: ------------------------------------------------------------------------ =============================== [ INFO: suspicious RCU usage. ] 4.6.0-rc4-next-20160422 #1 Not tainted ------------------------------- include/trace/events/power.h:328 suspicious rcu_dereference_check() usage! other info that might help us debug this: RCU used illegally from idle CPU! rcu_scheduler_active = 1, debug_locks = 0 RCU used illegally from extended quiescent state! no locks held by swapper/0/0. stack backtrace: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.6.0-rc4-next-20160422 #1 Hardware name: Generic OMAP3-GP (Flattened Device Tree) [] (unwind_backtrace) from [] (show_stack+0x10/0x14) [] (show_stack) from [] (dump_stack+0xa8/0xe0) [] (dump_stack) from [] (pwrdm_set_next_pwrst+0xf8/0x1cc) [] (pwrdm_set_next_pwrst) from [] (omap3_enter_idle_bm+0x1b8/0x1e8) [] (omap3_enter_idle_bm) from [] (cpuidle_enter_state+0x84/0x408) [] (cpuidle_enter_state) from [] (cpu_startup_entry+0x1c8/0x3f0) [] (cpu_startup_entry) from [] (start_kernel+0x354/0x3cc) ------------------------------------------------------------------------ [] (unwind_backtrace) from [] (show_stack+0x10/0x14) [] (show_stack) from [] (dump_stack+0xa8/0xe0) [] (dump_stack) from [] (_pwrdm_state_switch+0x188/0x32c) [] (_pwrdm_state_switch) from [] (_pwrdm_post_transition_cb+0xc/0x14) [] (_pwrdm_post_transition_cb) from [] (pwrdm_for_each+0x30/0x5c) [] (pwrdm_for_each) from [] (pwrdm_post_transition+0x24/0x30) [] (pwrdm_post_transition) from [] (omap_sram_idle+0xfc/0x240) [] (omap_sram_idle) from [] (omap3_enter_idle_bm+0xf0/0x1e8) [] (omap3_enter_idle_bm) from [] (cpuidle_enter_state+0x84/0x408) [] (cpuidle_enter_state) from [] (cpu_startup_entry+0x1c8/0x3f0) [] (cpu_startup_entry) from [] (start_kernel+0x354/0x3cc) ------------------------------------------------------------------------ These are caused by event tracing from the idle loop, and they were exposed by commit 293e2421fe25 ("rcu: Remove superfluous versions of rcu_read_lock_sched_held()"), which suppressed some false negatives. The current commit therefore adds the _rcuidle suffix to make RCU aware of this implicit use of RCU by event tracing, thus preventing both splats. Reported-by: Guenter Roeck Signed-off-by: Paul E. McKenney Tested-by: Guenter Roeck Tested-by: Tony Lindgren Cc: Russell King Reviewed-by: Steven Rostedt Cc: Cc: diff --git a/arch/arm/mach-omap2/powerdomain.c b/arch/arm/mach-omap2/powerdomain.c index 78af6d8..daf2753 100644 --- a/arch/arm/mach-omap2/powerdomain.c +++ b/arch/arm/mach-omap2/powerdomain.c @@ -186,8 +186,9 @@ static int _pwrdm_state_switch(struct powerdomain *pwrdm, int flag) trace_state = (PWRDM_TRACE_STATES_FLAG | ((next & OMAP_POWERSTATE_MASK) << 8) | ((prev & OMAP_POWERSTATE_MASK) << 0)); - trace_power_domain_target(pwrdm->name, trace_state, - smp_processor_id()); + trace_power_domain_target_rcuidle(pwrdm->name, + trace_state, + smp_processor_id()); } break; default: @@ -523,8 +524,8 @@ int pwrdm_set_next_pwrst(struct powerdomain *pwrdm, u8 pwrst) if (arch_pwrdm && arch_pwrdm->pwrdm_set_next_pwrst) { /* Trace the pwrdm desired target state */ - trace_power_domain_target(pwrdm->name, pwrst, - smp_processor_id()); + trace_power_domain_target_rcuidle(pwrdm->name, pwrst, + smp_processor_id()); /* Program the pwrdm desired target state */ ret = arch_pwrdm->pwrdm_set_next_pwrst(pwrdm, pwrst); } -- cgit v0.10.2 From 7c64cc0531fa0d9720f9e15a0a0d97bcad1d1cd1 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 26 Apr 2016 10:42:25 -0700 Subject: arm: Use _rcuidle for smp_cross_call() tracepoints Further testing with false negatives suppressed by commit 293e2421fe25 ("rcu: Remove superfluous versions of rcu_read_lock_sched_held()") identified another unprotected use of RCU from the idle loop. Because RCU actively ignores idle-loop code (for energy-efficiency reasons, among other things), using RCU from the idle loop can result in too-short grace periods, in turn resulting in arbitrary misbehavior. The resulting lockdep-RCU splat is as follows: ------------------------------------------------------------------------ =============================== [ INFO: suspicious RCU usage. ] 4.6.0-rc5-next-20160426+ #1112 Not tainted ------------------------------- include/trace/events/ipi.h:35 suspicious rcu_dereference_check() usage! other info that might help us debug this: RCU used illegally from idle CPU! rcu_scheduler_active = 1, debug_locks = 0 RCU used illegally from extended quiescent state! no locks held by swapper/0/0. stack backtrace: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.6.0-rc5-next-20160426+ #1112 Hardware name: Generic OMAP4 (Flattened Device Tree) [] (unwind_backtrace) from [] (show_stack+0x10/0x14) [] (show_stack) from [] (dump_stack+0xb0/0xe4) [] (dump_stack) from [] (smp_cross_call+0xbc/0x188) [] (smp_cross_call) from [] (generic_exec_single+0x9c/0x15c) [] (generic_exec_single) from [] (smp_call_function_single_async+0 x38/0x9c) [] (smp_call_function_single_async) from [] (cpuidle_coupled_poke_others+0x8c/0xa8) [] (cpuidle_coupled_poke_others) from [] (cpuidle_enter_state_coupled+0x26c/0x390) [] (cpuidle_enter_state_coupled) from [] (cpu_startup_entry+0x198/0x3a0) [] (cpu_startup_entry) from [] (start_kernel+0x354/0x3c8) [] (start_kernel) from [<8000807c>] (0x8000807c) ------------------------------------------------------------------------ Reported-by: Tony Lindgren Signed-off-by: Paul E. McKenney Tested-by: Tony Lindgren Tested-by: Guenter Roeck Cc: Russell King Cc: Steven Rostedt Cc: Cc: diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index baee702..7afe48a 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -486,7 +486,7 @@ static const char *ipi_types[NR_IPI] __tracepoint_string = { static void smp_cross_call(const struct cpumask *target, unsigned int ipinr) { - trace_ipi_raise(target, ipi_types[ipinr]); + trace_ipi_raise_rcuidle(target, ipi_types[ipinr]); __smp_cross_call(target, ipinr); } -- cgit v0.10.2 From ef5bdccf6d4363fd934035e0b1ca8445975e1d89 Mon Sep 17 00:00:00 2001 From: Janusz Krzysztofik Date: Thu, 16 Jun 2016 21:56:30 +0200 Subject: ARM: OMAP1: fix ams-delta FIQ handler to work with sparse IRQ After OMAP1 IRQ definitions have been changed by commit 685e2d08c54b ("ARM: OMAP1: Change interrupt numbering for sparse IRQ") introduced in v4.2, ams-delta FIQ handler which depends on them no longer works as expected. Fix it. Created and tested on Amstrad Delta against Linux-4.7-rc3 Signed-off-by: Janusz Krzysztofik Signed-off-by: Tony Lindgren diff --git a/arch/arm/mach-omap1/ams-delta-fiq-handler.S b/arch/arm/mach-omap1/ams-delta-fiq-handler.S index 5d7fb59..bf60844 100644 --- a/arch/arm/mach-omap1/ams-delta-fiq-handler.S +++ b/arch/arm/mach-omap1/ams-delta-fiq-handler.S @@ -43,8 +43,8 @@ #define OTHERS_MASK (MODEM_IRQ_MASK | HOOK_SWITCH_MASK) /* IRQ handler register bitmasks */ -#define DEFERRED_FIQ_MASK (0x1 << (INT_DEFERRED_FIQ % IH2_BASE)) -#define GPIO_BANK1_MASK (0x1 << INT_GPIO_BANK1) +#define DEFERRED_FIQ_MASK OMAP_IRQ_BIT(INT_DEFERRED_FIQ) +#define GPIO_BANK1_MASK OMAP_IRQ_BIT(INT_GPIO_BANK1) /* Driver buffer byte offsets */ #define BUF_MASK (FIQ_MASK * 4) @@ -110,7 +110,7 @@ ENTRY(qwerty_fiqin_start) mov r8, #2 @ reset FIQ agreement str r8, [r12, #IRQ_CONTROL_REG_OFFSET] - cmp r10, #INT_GPIO_BANK1 @ is it GPIO bank interrupt? + cmp r10, #(INT_GPIO_BANK1 - NR_IRQS_LEGACY) @ is it GPIO interrupt? beq gpio @ yes - process it mov r8, #1 diff --git a/arch/arm/mach-omap1/ams-delta-fiq.c b/arch/arm/mach-omap1/ams-delta-fiq.c index d1f1209..ec760ae 100644 --- a/arch/arm/mach-omap1/ams-delta-fiq.c +++ b/arch/arm/mach-omap1/ams-delta-fiq.c @@ -109,7 +109,8 @@ void __init ams_delta_init_fiq(void) * Since no set_type() method is provided by OMAP irq chip, * switch to edge triggered interrupt type manually. */ - offset = IRQ_ILR0_REG_OFFSET + INT_DEFERRED_FIQ * 0x4; + offset = IRQ_ILR0_REG_OFFSET + + ((INT_DEFERRED_FIQ - NR_IRQS_LEGACY) & 0x1f) * 0x4; val = omap_readl(DEFERRED_FIQ_IH_BASE + offset) & ~(1 << 1); omap_writel(val, DEFERRED_FIQ_IH_BASE + offset); @@ -149,7 +150,7 @@ void __init ams_delta_init_fiq(void) /* * Redirect GPIO interrupts to FIQ */ - offset = IRQ_ILR0_REG_OFFSET + INT_GPIO_BANK1 * 0x4; + offset = IRQ_ILR0_REG_OFFSET + (INT_GPIO_BANK1 - NR_IRQS_LEGACY) * 0x4; val = omap_readl(OMAP_IH1_BASE + offset) | 1; omap_writel(val, OMAP_IH1_BASE + offset); } diff --git a/arch/arm/mach-omap1/include/mach/ams-delta-fiq.h b/arch/arm/mach-omap1/include/mach/ams-delta-fiq.h index adb5e76..6dfc3e1 100644 --- a/arch/arm/mach-omap1/include/mach/ams-delta-fiq.h +++ b/arch/arm/mach-omap1/include/mach/ams-delta-fiq.h @@ -14,6 +14,8 @@ #ifndef __AMS_DELTA_FIQ_H #define __AMS_DELTA_FIQ_H +#include + /* * Interrupt number used for passing control from FIQ to IRQ. * IRQ12, described as reserved, has been selected. -- cgit v0.10.2 From 970f9091d25df14e9540ec7ff48a2f709e284cd1 Mon Sep 17 00:00:00 2001 From: Tero Kristo Date: Thu, 16 Jun 2016 15:25:18 +0300 Subject: ARM: OMAP2+: timer: add probe for clocksources A few platforms are currently missing clocksource_probe() completely in their time_init functionality. On OMAP3430 for example, this is causing cpuidle to be pretty much dead, as the counter32k is not going to be registered and instead a gptimer is used as a clocksource. This will tick in periodic mode, preventing any deeper idle states. While here, also drop one unnecessary check for populated DT before existing clocksource_probe() call. Signed-off-by: Tero Kristo Signed-off-by: Tony Lindgren diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c index 5b385bb..cb9497a 100644 --- a/arch/arm/mach-omap2/timer.c +++ b/arch/arm/mach-omap2/timer.c @@ -496,8 +496,7 @@ void __init omap_init_time(void) __omap_sync32k_timer_init(1, "timer_32k_ck", "ti,timer-alwon", 2, "timer_sys_ck", NULL, false); - if (of_have_populated_dt()) - clocksource_probe(); + clocksource_probe(); } #if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_SOC_AM43XX) @@ -505,6 +504,8 @@ void __init omap3_secure_sync32k_timer_init(void) { __omap_sync32k_timer_init(12, "secure_32k_fck", "ti,timer-secure", 2, "timer_sys_ck", NULL, false); + + clocksource_probe(); } #endif /* CONFIG_ARCH_OMAP3 */ @@ -513,6 +514,8 @@ void __init omap3_gptimer_timer_init(void) { __omap_sync32k_timer_init(2, "timer_sys_ck", NULL, 1, "timer_sys_ck", "ti,timer-alwon", true); + + clocksource_probe(); } #endif -- cgit v0.10.2 From d279f7a7e95af6bb4b5eaea3527d1f85a28c5cf6 Mon Sep 17 00:00:00 2001 From: Dave Gerlach Date: Wed, 15 Jun 2016 11:45:28 +0530 Subject: ARM: dts: am437x-sk-evm: Reduce i2c0 bus speed for tps65218 Based on the latest timing specifications for the TPS65218 from the data sheet, http://www.ti.com/lit/ds/symlink/tps65218.pdf, document SLDS206 from November 2014, we must change the i2c bus speed to better fit within the minimum high SCL time required for proper i2c transfer. When running at 400khz, measurements show that SCL spends 0.8125 uS/1.666 uS high/low which violates the requirement for minimum high period of SCL provided in datasheet Table 7.6 which is 1 uS. Switching to 100khz gives us 5 uS/5 uS high/low which both fall above the minimum given values for 100 khz, 4.0 uS/4.7 uS high/low. Without this patch occasionally a voltage set operation from the kernel will appear to have worked but the actual voltage reflected on the PMIC will not have updated, causing problems especially with cpufreq that may update to a higher OPP without actually raising the voltage on DCDC2, leading to a hang. Signed-off-by: Dave Gerlach Signed-off-by: Nishanth Menon Signed-off-by: Franklin S Cooper Jr Signed-off-by: Aparna Balasubramanian Signed-off-by: Keerthy Signed-off-by: Tony Lindgren diff --git a/arch/arm/boot/dts/am437x-sk-evm.dts b/arch/arm/boot/dts/am437x-sk-evm.dts index d82dd6e..5687d6b 100644 --- a/arch/arm/boot/dts/am437x-sk-evm.dts +++ b/arch/arm/boot/dts/am437x-sk-evm.dts @@ -418,7 +418,7 @@ status = "okay"; pinctrl-names = "default"; pinctrl-0 = <&i2c0_pins>; - clock-frequency = <400000>; + clock-frequency = <100000>; tps@24 { compatible = "ti,tps65218"; -- cgit v0.10.2