[PATCH 1/4] regmap: irq: Fix lost interrupts by introducing handle_reread

From: Tony Lindgren
Date: Wed Mar 22 2017 - 13:12:28 EST


At least Motorola CPCAP PMIC needs it's device interrupts re-read
until there are no more interrupts. Otherwise the PMIC interrupt to
the SoC will eventually stop toggling. This seems to be a bug in the
CPCAP PMIC where it can stop driving the GPIO interrupt to the SoC
with pending CPCAP interrupts.

Let's allow handling issues like this by introducing a flag for
handle_reread and by splitting regmap_irq_thread() into two separate
functions for regmap_read_irq_status() and regmap_irq_handle_pending().

Cc: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
Cc: Lee Jones <lee.jones@xxxxxxxxxx>
Cc: Marcel Partap <mpartap@xxxxxxx>
Cc: Michael Scott <michael.scott@xxxxxxxxxx>
Tested-by: Sebastian Reichel <sre@xxxxxxxxxx>
Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
---
drivers/base/regmap/regmap-irq.c | 77 +++++++++++++++++++++++++++-------------
include/linux/regmap.h | 2 ++
2 files changed, 55 insertions(+), 24 deletions(-)

diff --git a/drivers/base/regmap/regmap-irq.c b/drivers/base/regmap/regmap-irq.c
--- a/drivers/base/regmap/regmap-irq.c
+++ b/drivers/base/regmap/regmap-irq.c
@@ -259,27 +259,11 @@ static const struct irq_chip regmap_irq_chip = {
.irq_set_wake = regmap_irq_set_wake,
};

-static irqreturn_t regmap_irq_thread(int irq, void *d)
+static int regmap_read_irq_status(struct regmap_irq_chip_data *data)
{
- struct regmap_irq_chip_data *data = d;
const struct regmap_irq_chip *chip = data->chip;
struct regmap *map = data->map;
int ret, i;
- bool handled = false;
- u32 reg;
-
- if (chip->handle_pre_irq)
- chip->handle_pre_irq(chip->irq_drv_data);
-
- if (chip->runtime_pm) {
- ret = pm_runtime_get_sync(map->dev);
- if (ret < 0) {
- dev_err(map->dev, "IRQ thread failed to resume: %d\n",
- ret);
- pm_runtime_put(map->dev);
- goto exit;
- }
- }

/*
* Read in the statuses, using a single bulk read if possible
@@ -299,7 +283,7 @@ static irqreturn_t regmap_irq_thread(int irq, void *d)
if (ret != 0) {
dev_err(map->dev, "Failed to read IRQ status: %d\n",
ret);
- goto exit;
+ return ret;
}

for (i = 0; i < data->chip->num_regs; i++) {
@@ -315,7 +299,7 @@ static irqreturn_t regmap_irq_thread(int irq, void *d)
break;
default:
BUG();
- goto exit;
+ return ret;
}
}

@@ -330,13 +314,21 @@ static irqreturn_t regmap_irq_thread(int irq, void *d)
dev_err(map->dev,
"Failed to read IRQ status: %d\n",
ret);
- if (chip->runtime_pm)
- pm_runtime_put(map->dev);
- goto exit;
+ return ret;
}
}
}

+ return 0;
+}
+
+static int regmap_irq_handle_pending(struct regmap_irq_chip_data *data)
+{
+ const struct regmap_irq_chip *chip = data->chip;
+ struct regmap *map = data->map;
+ int ret, i, handled = 0;
+ u32 reg;
+
/*
* Ignore masked IRQs and ack if we need to; we ack early so
* there is no race between handling and acknowleding the
@@ -361,14 +353,51 @@ static irqreturn_t regmap_irq_thread(int irq, void *d)
if (data->status_buf[chip->irqs[i].reg_offset /
map->reg_stride] & chip->irqs[i].mask) {
handle_nested_irq(irq_find_mapping(data->domain, i));
- handled = true;
+ handled++;
+ }
+ }
+
+ return handled;
+}
+
+static irqreturn_t regmap_irq_thread(int irq, void *d)
+{
+ struct regmap_irq_chip_data *data = d;
+ const struct regmap_irq_chip *chip = data->chip;
+ struct regmap *map = data->map;
+ int ret, handled = 0;
+
+ if (chip->handle_pre_irq)
+ chip->handle_pre_irq(chip->irq_drv_data);
+
+ if (chip->runtime_pm) {
+ ret = pm_runtime_get_sync(map->dev);
+ if (ret < 0) {
+ dev_err(map->dev, "IRQ thread failed to resume: %d\n",
+ ret);
+ goto out_runtime_put;
}
}

+ do {
+ ret = regmap_read_irq_status(data);
+ if (ret)
+ goto out_runtime_put;
+
+ ret = regmap_irq_handle_pending(data);
+ if (ret < 0)
+ goto out_runtime_put;
+
+ if (!ret)
+ break;
+
+ handled += ret;
+ } while (chip->handle_reread);
+
+out_runtime_put:
if (chip->runtime_pm)
pm_runtime_put(map->dev);

-exit:
if (chip->handle_post_irq)
chip->handle_post_irq(chip->irq_drv_data);

diff --git a/include/linux/regmap.h b/include/linux/regmap.h
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -897,6 +897,7 @@ struct regmap_irq {
* @ack_invert: Inverted ack register: cleared bits for ack.
* @wake_invert: Inverted wake register: cleared bits are wake enabled.
* @type_invert: Invert the type flags.
+ * @handle_reread: Read interrupt status until no more interrupts are seen.
* @runtime_pm: Hold a runtime PM lock on the device when accessing it.
*
* @num_regs: Number of registers in each control bank.
@@ -934,6 +935,7 @@ struct regmap_irq_chip {
bool wake_invert:1;
bool runtime_pm:1;
bool type_invert:1;
+ bool handle_reread:1;

int num_regs;

--
2.11.1