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soc/tegra: pmc: Fix unsafe generic_handle_irq() call

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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 <petlozup@nvidia.com>
Signed-off-by: Prathamesh Shete <pshete@nvidia.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
[treding@nvidia.com: miscellaneous cleanups]
Signed-off-by: Thierry Reding <treding@nvidia.com>
This commit is contained in:
Prathamesh Shete 2026-01-08 05:01:03 +00:00 committed by Thierry Reding
parent 8f0b4cce44
commit e6d96073af
1 changed files with 74 additions and 30 deletions
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104
drivers/soc/tegra/pmc.c
View File

@ -28,6 +28,7 @@
#include <linux/iopoll.h>
#include <linux/irqdomain.h>
#include <linux/irq.h>
#include <linux/irq_work.h>
#include <linux/kernel.h>
#include <linux/of_address.h>
#include <linux/of_clk.h>
@ -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