From e6d96073af681780820c94079b978474a8a44413 Mon Sep 17 00:00:00 2001 From: Prathamesh Shete Date: Thu, 8 Jan 2026 05:01:03 +0000 Subject: [PATCH] soc/tegra: pmc: Fix unsafe generic_handle_irq() call Currently, when resuming from system suspend on Tegra platforms, the following warning is observed: WARNING: CPU: 0 PID: 14459 at kernel/irq/irqdesc.c:666 Call trace: handle_irq_desc+0x20/0x58 (P) tegra186_pmc_wake_syscore_resume+0xe4/0x15c syscore_resume+0x3c/0xb8 suspend_devices_and_enter+0x510/0x540 pm_suspend+0x16c/0x1d8 The warning occurs because generic_handle_irq() is being called from a non-interrupt context which is considered as unsafe. Fix this warning by deferring generic_handle_irq() call to an IRQ work which gets executed in hard IRQ context where generic_handle_irq() can be called safely. When PREEMPT_RT kernels are used, regular IRQ work (initialized with init_irq_work) is deferred to run in per-CPU kthreads in preemptible context rather than hard IRQ context. Hence, use the IRQ_WORK_INIT_HARD variant so that with PREEMPT_RT kernels, the IRQ work is processed in hardirq context instead of being deferred to a thread which is required for calling generic_handle_irq(). On non-PREEMPT_RT kernels, both init_irq_work() and IRQ_WORK_INIT_HARD() execute in IRQ context, so this change has no functional impact for standard kernel configurations. Signed-off-by: Petlozu Pravareshwar Signed-off-by: Prathamesh Shete Reviewed-by: Jon Hunter Tested-by: Jon Hunter [treding@nvidia.com: miscellaneous cleanups] Signed-off-by: Thierry Reding --- drivers/soc/tegra/pmc.c | 104 ++++++++++++++++++++++++++++------------ 1 file changed, 74 insertions(+), 30 deletions(-) diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c index f3760a3b3026d..407fa840814c3 100644 --- a/drivers/soc/tegra/pmc.c +++ b/drivers/soc/tegra/pmc.c @@ -28,6 +28,7 @@ #include #include #include +#include #include #include #include @@ -468,6 +469,10 @@ struct tegra_pmc { unsigned long *wake_sw_status_map; unsigned long *wake_cntrl_level_map; struct syscore syscore; + + /* Pending wake IRQ processing */ + struct irq_work wake_work; + u32 *wake_status; }; static struct tegra_pmc *pmc = &(struct tegra_pmc) { @@ -1905,6 +1910,50 @@ static int tegra_pmc_parse_dt(struct tegra_pmc *pmc, struct device_node *np) return 0; } +/* translate sc7 wake sources back into IRQs to catch edge triggered wakeups */ +static void tegra186_pmc_wake_handler(struct irq_work *work) +{ + struct tegra_pmc *pmc = container_of(work, struct tegra_pmc, wake_work); + unsigned int i, wake; + + for (i = 0; i < pmc->soc->max_wake_vectors; i++) { + unsigned long status = pmc->wake_status[i]; + + for_each_set_bit(wake, &status, 32) { + irq_hw_number_t hwirq = wake + (i * 32); + struct irq_desc *desc; + unsigned int irq; + + irq = irq_find_mapping(pmc->domain, hwirq); + if (!irq) { + dev_warn(pmc->dev, + "No IRQ found for WAKE#%lu!\n", + hwirq); + continue; + } + + dev_dbg(pmc->dev, + "Resume caused by WAKE#%lu mapped to IRQ#%u\n", + hwirq, irq); + + desc = irq_to_desc(irq); + if (!desc) { + dev_warn(pmc->dev, + "No descriptor found for IRQ#%u\n", + irq); + continue; + } + + if (!desc->action || !desc->action->name) + continue; + + generic_handle_irq(irq); + } + + pmc->wake_status[i] = 0; + } +} + static int tegra_pmc_init(struct tegra_pmc *pmc) { if (pmc->soc->max_wake_events > 0) { @@ -1923,6 +1972,18 @@ static int tegra_pmc_init(struct tegra_pmc *pmc) pmc->wake_cntrl_level_map = bitmap_zalloc(pmc->soc->max_wake_events, GFP_KERNEL); if (!pmc->wake_cntrl_level_map) return -ENOMEM; + + pmc->wake_status = kcalloc(pmc->soc->max_wake_vectors, sizeof(u32), GFP_KERNEL); + if (!pmc->wake_status) + return -ENOMEM; + + /* + * Initialize IRQ work for processing wake IRQs. Must use + * HARD_IRQ variant to run in hard IRQ context on PREEMPT_RT + * because we call generic_handle_irq() which requires hard + * IRQ context. + */ + pmc->wake_work = IRQ_WORK_INIT_HARD(tegra186_pmc_wake_handler); } if (pmc->soc->init) @@ -3129,47 +3190,30 @@ static void wke_clear_wake_status(struct tegra_pmc *pmc) } } -/* translate sc7 wake sources back into IRQs to catch edge triggered wakeups */ -static void tegra186_pmc_process_wake_events(struct tegra_pmc *pmc, unsigned int index, - unsigned long status) -{ - unsigned int wake; - - dev_dbg(pmc->dev, "Wake[%d:%d] status=%#lx\n", (index * 32) + 31, index * 32, status); - - for_each_set_bit(wake, &status, 32) { - irq_hw_number_t hwirq = wake + 32 * index; - struct irq_desc *desc; - unsigned int irq; - - irq = irq_find_mapping(pmc->domain, hwirq); - - desc = irq_to_desc(irq); - if (!desc || !desc->action || !desc->action->name) { - dev_dbg(pmc->dev, "Resume caused by WAKE%ld, IRQ %d\n", hwirq, irq); - continue; - } - - dev_dbg(pmc->dev, "Resume caused by WAKE%ld, %s\n", hwirq, desc->action->name); - generic_handle_irq(irq); - } -} - static void tegra186_pmc_wake_syscore_resume(void *data) { - u32 status, mask; unsigned int i; + u32 mask; for (i = 0; i < pmc->soc->max_wake_vectors; i++) { mask = readl(pmc->wake + WAKE_AOWAKE_TIER2_ROUTING(i)); - status = readl(pmc->wake + WAKE_AOWAKE_STATUS_R(i)) & mask; - - tegra186_pmc_process_wake_events(pmc, i, status); + pmc->wake_status[i] = readl(pmc->wake + WAKE_AOWAKE_STATUS_R(i)) & mask; } + + /* Schedule IRQ work to process wake IRQs (if any) */ + irq_work_queue(&pmc->wake_work); } static int tegra186_pmc_wake_syscore_suspend(void *data) { + unsigned int i; + + /* Check if there are unhandled wake IRQs */ + for (i = 0; i < pmc->soc->max_wake_vectors; i++) + if (pmc->wake_status[i]) + dev_warn(pmc->dev, + "Unhandled wake IRQs pending vector[%u]: 0x%x\n", + i, pmc->wake_status[i]); wke_read_sw_wake_status(pmc); /* flip the wakeup trigger for dual-edge triggered pads -- 2.47.3