On 09/04/19 1:15 AM, Tony Lindgren wrote:
From: Russell King <rmk+kernel@xxxxxxxxxxxxxxx>
Commit b764a5863fd8 ("gpio: omap: Remove custom PM calls and use cpu_pm
instead") moved interrupt using GPIO banks to idle with cpu_pm in order
to drop the use of pm_runtime_irq_safe() in a later patch. The GPIO
banks with no interrupts claimed are still being idled based on PM
runtime calls. However this caused a regression for am437x suspend for
rtc+ddr idle mode as reported by Keerthy <j-keerthy@xxxxxx>. The fix
to this is:
Bump the pm_runtime usage count while interrupts are in use, rather
than failing the pm_runtime callbacks. The logic here is a little
non-obvious - the calling order will be:
omap_gpio_irq_bus_lock()
(optionally) raw_spin_lock_irqsave(desc->lock)
omap_gpio_irq_startup()
(optionally) raw_spin_unlock_irqrestore(desc->lock)
gpio_irq_bus_sync_unlock()
As the irq_startup method may be called with interrupts disabled, we
must not use pm_runtime_get() here, so as the bus lock takes an initial
pm reference count us, use pm_runtime_get_if_in_use() which will merely
increment the use count.
Tony,
Applied cleanly on linux-next. I had to manually apply this on your
for-next branch. Tested for AM4 RTC+DDR and DS0 back and forth.
Regards,
Keerthy
Cc: Aaro Koskinen <aaro.koskinen@xxxxxx>
Cc: Grygorii Strashko <grygorii.strashko@xxxxxx>
Cc: Keerthy <j-keerthy@xxxxxx>
Cc: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
Cc: Tero Kristo <t-kristo@xxxxxx>
Fixes: b764a5863fd8 ("gpio: omap: Remove custom PM calls and use cpu_pm instead")
Reported-by: Keerthy <j-keerthy@xxxxxx>
Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxx>
[tony@xxxxxxxxxxx: updated patch description for regression fix]
Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
---
AFAIK this is only needed with patches heading to v5.2, so this is based on
Linux next. We can always backport as needed.
---
drivers/gpio/gpio-omap.c | 23 +++++++----------------
1 file changed, 7 insertions(+), 16 deletions(-)
diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c
@@ -811,6 +811,9 @@ static unsigned int omap_gpio_irq_startup(struct irq_data *d)
unsigned long flags;
unsigned offset = d->hwirq;
+ /* Take a reference on the runtime PM to prevent RPM suspends */
+ WARN_ON(pm_runtime_get_if_in_use(bank->chip.parent) == 0);
+
raw_spin_lock_irqsave(&bank->lock, flags);
if (!LINE_USED(bank->mod_usage, offset))
@@ -844,6 +847,8 @@ static void omap_gpio_irq_shutdown(struct irq_data *d)
omap_clear_gpio_debounce(bank, offset);
omap_disable_gpio_module(bank, offset);
raw_spin_unlock_irqrestore(&bank->lock, flags);
+
+ pm_runtime_put(bank->chip.parent);
}
static void omap_gpio_irq_bus_lock(struct irq_data *data)
@@ -1719,40 +1724,26 @@ static int __maybe_unused omap_gpio_runtime_suspend(struct device *dev)
{
struct gpio_bank *bank = dev_get_drvdata(dev);
unsigned long flags;
- int error = 0;
raw_spin_lock_irqsave(&bank->lock, flags);
- /* Must be idled only by CPU_CLUSTER_PM_ENTER? */
- if (bank->irq_usage) {
- error = -EBUSY;
- goto unlock;
- }
omap_gpio_idle(bank, true);
bank->is_suspended = true;
-unlock:
raw_spin_unlock_irqrestore(&bank->lock, flags);
- return error;
+ return 0;
}
static int __maybe_unused omap_gpio_runtime_resume(struct device *dev)
{
struct gpio_bank *bank = dev_get_drvdata(dev);
unsigned long flags;
- int error = 0;
raw_spin_lock_irqsave(&bank->lock, flags);
- /* Must be unidled only by CPU_CLUSTER_PM_ENTER? */
- if (bank->irq_usage) {
- error = -EBUSY;
- goto unlock;
- }
omap_gpio_unidle(bank);
bank->is_suspended = false;
-unlock:
raw_spin_unlock_irqrestore(&bank->lock, flags);
- return error;
+ return 0;
}
static const struct dev_pm_ops gpio_pm_ops = {
