[tip: irq/core] irqchip/imx-irqsteer: Handle runtime power management correctly

From: tip-bot2 for Shenwei Wang
Date: Mon Jul 15 2024 - 09:21:15 EST


The following commit has been merged into the irq/core branch of tip:

Commit-ID: 33b1c47d1fc0b5f06a393bb915db85baacba18ea
Gitweb: https://git.kernel.org/tip/33b1c47d1fc0b5f06a393bb915db85baacba18ea
Author: Shenwei Wang <shenwei.wang@xxxxxxx>
AuthorDate: Wed, 03 Jul 2024 11:32:50 -05:00
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Mon, 15 Jul 2024 15:13:56 +02:00

irqchip/imx-irqsteer: Handle runtime power management correctly

The power domain is automatically activated from clk_prepare(). However, on
certain platforms like i.MX8QM and i.MX8QXP, the power-on handling invokes
sleeping functions, which triggers the 'scheduling while atomic' bug in the
context switch path during device probing:

BUG: scheduling while atomic: kworker/u13:1/48/0x00000002
Call trace:
__schedule_bug+0x54/0x6c
__schedule+0x7f0/0xa94
schedule+0x5c/0xc4
schedule_preempt_disabled+0x24/0x40
__mutex_lock.constprop.0+0x2c0/0x540
__mutex_lock_slowpath+0x14/0x20
mutex_lock+0x48/0x54
clk_prepare_lock+0x44/0xa0
clk_prepare+0x20/0x44
imx_irqsteer_resume+0x28/0xe0
pm_generic_runtime_resume+0x2c/0x44
__genpd_runtime_resume+0x30/0x80
genpd_runtime_resume+0xc8/0x2c0
__rpm_callback+0x48/0x1d8
rpm_callback+0x6c/0x78
rpm_resume+0x490/0x6b4
__pm_runtime_resume+0x50/0x94
irq_chip_pm_get+0x2c/0xa0
__irq_do_set_handler+0x178/0x24c
irq_set_chained_handler_and_data+0x60/0xa4
mxc_gpio_probe+0x160/0x4b0

Cure this by implementing the irq_bus_lock/sync_unlock() interrupt chip
callbacks and handle power management in them as they are invoked from
non-atomic context.

[ tglx: Rewrote change log, added Fixes tag ]

Fixes: 0136afa08967 ("irqchip: Add driver for imx-irqsteer controller")
Signed-off-by: Shenwei Wang <shenwei.wang@xxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20240703163250.47887-1-shenwei.wang@xxxxxxx
---
drivers/irqchip/irq-imx-irqsteer.c | 24 +++++++++++++++++++++---
1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/drivers/irqchip/irq-imx-irqsteer.c b/drivers/irqchip/irq-imx-irqsteer.c
index 20cf7a9..75a0e98 100644
--- a/drivers/irqchip/irq-imx-irqsteer.c
+++ b/drivers/irqchip/irq-imx-irqsteer.c
@@ -36,6 +36,7 @@ struct irqsteer_data {
int channel;
struct irq_domain *domain;
u32 *saved_reg;
+ struct device *dev;
};

static int imx_irqsteer_get_reg_index(struct irqsteer_data *data,
@@ -72,10 +73,26 @@ static void imx_irqsteer_irq_mask(struct irq_data *d)
raw_spin_unlock_irqrestore(&data->lock, flags);
}

+static void imx_irqsteer_irq_bus_lock(struct irq_data *d)
+{
+ struct irqsteer_data *data = d->chip_data;
+
+ pm_runtime_get_sync(data->dev);
+}
+
+static void imx_irqsteer_irq_bus_sync_unlock(struct irq_data *d)
+{
+ struct irqsteer_data *data = d->chip_data;
+
+ pm_runtime_put_autosuspend(data->dev);
+}
+
static const struct irq_chip imx_irqsteer_irq_chip = {
- .name = "irqsteer",
- .irq_mask = imx_irqsteer_irq_mask,
- .irq_unmask = imx_irqsteer_irq_unmask,
+ .name = "irqsteer",
+ .irq_mask = imx_irqsteer_irq_mask,
+ .irq_unmask = imx_irqsteer_irq_unmask,
+ .irq_bus_lock = imx_irqsteer_irq_bus_lock,
+ .irq_bus_sync_unlock = imx_irqsteer_irq_bus_sync_unlock,
};

static int imx_irqsteer_irq_map(struct irq_domain *h, unsigned int irq,
@@ -150,6 +167,7 @@ static int imx_irqsteer_probe(struct platform_device *pdev)
if (!data)
return -ENOMEM;

+ data->dev = &pdev->dev;
data->regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(data->regs)) {
dev_err(&pdev->dev, "failed to initialize reg\n");