4.4-stable review patch. If anyone has any objections, please let me know.
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From: Jonathan Hunter jonathanh@nvidia.com
commit ac4ca4b9f4623ba5e1ea7a582f286567c611e027 upstream.
The tps6586x driver creates an irqchip that is used by its various child devices for managing interrupts. The tps6586x-rtc device is one of its children that uses the tps6586x irqchip. When using the tps6586x-rtc as a wake-up device from suspend, the following is seen:
PM: Syncing filesystems ... done. Freezing user space processes ... (elapsed 0.001 seconds) done. OOM killer disabled. Freezing remaining freezable tasks ... (elapsed 0.000 seconds) done. Disabling non-boot CPUs ... Entering suspend state LP1 Enabling non-boot CPUs ... CPU1 is up tps6586x 3-0034: failed to read interrupt status tps6586x 3-0034: failed to read interrupt status
The reason why the tps6586x interrupt status cannot be read is because the tps6586x interrupt is not masked during suspend and when the tps6586x-rtc interrupt occurs, to wake-up the device, the interrupt is seen before the i2c controller has been resumed in order to read the tps6586x interrupt status.
The tps6586x-rtc driver sets it's interrupt as a wake-up source during suspend, which gets propagated to the parent tps6586x interrupt. However, the tps6586x-rtc driver cannot disable it's interrupt during suspend otherwise we would never be woken up and so the tps6586x must disable it's interrupt instead.
Prevent the tps6586x interrupt handler from executing on exiting suspend before the i2c controller has been resumed by disabling the tps6586x interrupt on entering suspend and re-enabling it on resuming from suspend.
Cc: stable@vger.kernel.org Signed-off-by: Jon Hunter jonathanh@nvidia.com Reviewed-by: Dmitry Osipenko digetx@gmail.com Tested-by: Dmitry Osipenko digetx@gmail.com Acked-by: Thierry Reding treding@nvidia.com Signed-off-by: Lee Jones lee.jones@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/mfd/tps6586x.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+)
--- a/drivers/mfd/tps6586x.c +++ b/drivers/mfd/tps6586x.c @@ -594,6 +594,29 @@ static int tps6586x_i2c_remove(struct i2 return 0; }
+static int __maybe_unused tps6586x_i2c_suspend(struct device *dev) +{ + struct tps6586x *tps6586x = dev_get_drvdata(dev); + + if (tps6586x->client->irq) + disable_irq(tps6586x->client->irq); + + return 0; +} + +static int __maybe_unused tps6586x_i2c_resume(struct device *dev) +{ + struct tps6586x *tps6586x = dev_get_drvdata(dev); + + if (tps6586x->client->irq) + enable_irq(tps6586x->client->irq); + + return 0; +} + +static SIMPLE_DEV_PM_OPS(tps6586x_pm_ops, tps6586x_i2c_suspend, + tps6586x_i2c_resume); + static const struct i2c_device_id tps6586x_id_table[] = { { "tps6586x", 0 }, { }, @@ -604,6 +627,7 @@ static struct i2c_driver tps6586x_driver .driver = { .name = "tps6586x", .of_match_table = of_match_ptr(tps6586x_of_match), + .pm = &tps6586x_pm_ops, }, .probe = tps6586x_i2c_probe, .remove = tps6586x_i2c_remove,