From e509bd7da149dc34916037484cd7545b2d48a2b0 Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Mon, 5 Oct 2015 13:12:15 +0300 Subject: genirq: Allow migration of chained interrupts by installing default action When a CPU is offlined all interrupts that have an action are migrated to other still online CPUs. However, if the interrupt has chained handler installed this is not done. Chained handlers are used by GPIO drivers which support interrupts, for instance. When the affinity is not corrected properly we end up in situation where most interrupts are not arriving to the online CPUs anymore. For example on Intel Braswell system which has SD-card card detection signal connected to a GPIO the IO-APIC routing entries look like below after CPU1 is offlined: pin30, enabled , level, low , V(52), IRR(0), S(0), logical , D(03), M(1) pin31, enabled , level, low , V(42), IRR(0), S(0), logical , D(03), M(1) pin32, enabled , level, low , V(62), IRR(0), S(0), logical , D(03), M(1) pin5b, enabled , level, low , V(72), IRR(0), S(0), logical , D(03), M(1) The problem here is that the destination mask still contains both CPUs even if CPU1 is already offline. This means that the IO-APIC still routes interrupts to the other CPU as well. We solve the problem by providing a default action for chained interrupts. This action allows the migration code to correct affinity (as it finds desc->action != NULL). Also make the default action handler to emit a warning if for some reason a chained handler ends up calling it. Signed-off-by: Mika Westerberg Cc: Jiang Liu Link: http://lkml.kernel.org/r/1444039935-30475-1-git-send-email-mika.westerberg@linux.intel.com Signed-off-by: Thomas Gleixner --- kernel/irq/proc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/irq/proc.c') diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c index e3a8c9577ba6..7d6090519630 100644 --- a/kernel/irq/proc.c +++ b/kernel/irq/proc.c @@ -460,7 +460,7 @@ int show_interrupts(struct seq_file *p, void *v) for_each_online_cpu(j) any_count |= kstat_irqs_cpu(i, j); action = desc->action; - if (!action && !any_count) + if ((!action || action == &chained_action) && !any_count) goto out; seq_printf(p, "%*d: ", prec, i); -- cgit v1.2.3 From 4717f133736dec10605da9e29e707144c8d486df Mon Sep 17 00:00:00 2001 From: Grygorii Strashko Date: Tue, 10 Nov 2015 11:58:12 +0200 Subject: genirq/PM: Restore system wake up from chained interrupts Commit e509bd7da149 ("genirq: Allow migration of chained interrupts by installing default action") breaks PCS wake up IRQ behaviour on TI OMAP based platforms (dra7-evm). TI OMAP IRQ wake up configuration: GIC-irqchip->PCM_IRQ |- omap_prcm_register_chain_handler |- PRCM-irqchip -> PRCM_IO_IRQ |- pcs_irq_chain_handler |- pinctrl-irqchip -> PCS_uart1_wakeup_irq This happens because IRQ PM code (irq/pm.c) is expected to ignore chained interrupts by default: static bool suspend_device_irq(struct irq_desc *desc) { if (!desc->action || desc->no_suspend_depth) return false; - it's expected !desc->action = true for chained interrupts; but, after above change, all chained interrupt descriptors will have default action handler installed - chained_action. As result, chained interrupts will be silently disabled during system suspend. Hence, fix it by introducing helper function irq_desc_is_chained() and use it in suspend_device_irq() for chained interrupts identification and skip them, once detected. Fixes: e509bd7da149 ("genirq: Allow migration of chained interrupts..") Signed-off-by: Grygorii Strashko Reviewed-by: Mika Westerberg Cc: Tony Lindgren Cc: Cc: Cc: Tony Lindgren Link: http://lkml.kernel.org/r/1447149492-20699-1-git-send-email-grygorii.strashko@ti.com Signed-off-by: Thomas Gleixner --- kernel/irq/internals.h | 5 +++++ kernel/irq/pm.c | 3 ++- kernel/irq/proc.c | 2 +- 3 files changed, 8 insertions(+), 2 deletions(-) (limited to 'kernel/irq/proc.c') diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h index 05c2188271b8..fcab63c66905 100644 --- a/kernel/irq/internals.h +++ b/kernel/irq/internals.h @@ -199,6 +199,11 @@ static inline int irq_desc_get_node(struct irq_desc *desc) return irq_common_data_get_node(&desc->irq_common_data); } +static inline int irq_desc_is_chained(struct irq_desc *desc) +{ + return (desc->action && desc->action == &chained_action); +} + #ifdef CONFIG_PM_SLEEP bool irq_pm_check_wakeup(struct irq_desc *desc); void irq_pm_install_action(struct irq_desc *desc, struct irqaction *action); diff --git a/kernel/irq/pm.c b/kernel/irq/pm.c index 21c62617a35a..84ab239a00e2 100644 --- a/kernel/irq/pm.c +++ b/kernel/irq/pm.c @@ -70,7 +70,8 @@ void irq_pm_remove_action(struct irq_desc *desc, struct irqaction *action) static bool suspend_device_irq(struct irq_desc *desc) { - if (!desc->action || desc->no_suspend_depth) + if (!desc->action || irq_desc_is_chained(desc) || + desc->no_suspend_depth) return false; if (irqd_is_wakeup_set(&desc->irq_data)) { diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c index a916cf144b65..a2c02fd5d6d0 100644 --- a/kernel/irq/proc.c +++ b/kernel/irq/proc.c @@ -475,7 +475,7 @@ int show_interrupts(struct seq_file *p, void *v) for_each_online_cpu(j) any_count |= kstat_irqs_cpu(i, j); action = desc->action; - if ((!action || action == &chained_action) && !any_count) + if ((!action || irq_desc_is_chained(desc)) && !any_count) goto out; seq_printf(p, "%*d: ", prec, i); -- cgit v1.2.3