[PATCH 1/2] i2c: designware: Never suspend i2c-busses used for accessing the system PMIC

Hans de Goede
2017-02-27T09:38:29Z

Currently we are already setting a pm_runtime_disabled flag and disabling
runtime-pm for i2c-busses used for accessing the system PMIC on x86.
But this is not enough, there are ACPI opregions which may want to access
the PMIC during late-suspend and early-resume, so we need to completely
disable pm to be safe.

This commit renames the flag from pm_runtime_disabled to pm_disabled and
adds the following new behavior if the flag is set:

1) Call dev_pm_syscore_device(dev, true) which disables normal suspend /
resume and remove the pm_runtime_disabled check from dw_i2c_plat_resume
since that will now never get called. This fixes suspend_late handlers
which use ACPI PMIC opregions causing errors like these:

PM: Suspending system (freeze)
PM: suspend of devices complete after 1127.751 msecs
i2c_designware 808622C1:06: timeout waiting for bus ready
ACPI Exception: AE_ERROR, Returned by Handler for [UserDefinedRegion]
acpi 80860F14:02: Failed to change power state to D3hot
PM: late suspend of devices failed

2) Set IRQF_NO_SUSPEND irq flag. This fixes resume_early handlers which
handlers which use ACPI PMIC opregions causing errors like these:

PM: resume from suspend-to-idle
i2c_designware 808622C1:06: controller timed out
ACPI Exception: AE_ERROR, Returned by Handler for [UserDefinedRegion]

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
drivers/i2c/busses/i2c-designware-baytrail.c | 2 +-
drivers/i2c/busses/i2c-designware-core.c | 10 ++++++++--
drivers/i2c/busses/i2c-designware-core.h | 4 ++--
drivers/i2c/busses/i2c-designware-platdrv.c | 10 ++++------
4 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c
index 1749a0f..b8cc226 100644
--- a/drivers/i2c/busses/i2c-designware-baytrail.c
+++ b/drivers/i2c/busses/i2c-designware-baytrail.c
@@ -170,7 +170,7 @@ int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev)
dev_info(dev->dev, "I2C bus managed by PUNIT\n");
dev->acquire_lock = baytrail_i2c_acquire;
dev->release_lock = baytrail_i2c_release;
- dev->pm_runtime_disabled = true;
+ dev->pm_disabled = true;

pm_qos_add_request(&dev->pm_qos, PM_QOS_CPU_DMA_LATENCY,
PM_QOS_DEFAULT_VALUE);
diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c
index 8c3ba42..3d86059 100644
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -962,6 +962,7 @@ EXPORT_SYMBOL_GPL(i2c_dw_read_comp_param);
int i2c_dw_probe(struct dw_i2c_dev *dev)
{
struct i2c_adapter *adap = &dev->adapter;
+ unsigned long irq_flags;
int r;
u32 reg;

@@ -998,9 +999,14 @@ int i2c_dw_probe(struct dw_i2c_dev *dev)
adap->dev.parent = dev->dev;
i2c_set_adapdata(adap, dev);

+ if (dev->pm_disabled) {
+ dev_pm_syscore_device(dev->dev, true);
+ irq_flags = IRQF_NO_SUSPEND;
+ } else
+ irq_flags = IRQF_SHARED | IRQF_COND_SUSPEND;
+
i2c_dw_disable_int(dev);
- r = devm_request_irq(dev->dev, dev->irq, i2c_dw_isr,
- IRQF_SHARED | IRQF_COND_SUSPEND,
+ r = devm_request_irq(dev->dev, dev->irq, i2c_dw_isr, irq_flags,
dev_name(dev->dev), dev);
if (r) {
dev_err(dev->dev, "failure requesting irq %i: %d\n",
diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
index a8e74ca..a4ac473 100644
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -79,7 +79,7 @@
* @pm_qos: pm_qos_request used while holding a hardware lock on the bus
* @acquire_lock: function to acquire a hardware lock on the bus
* @release_lock: function to release a hardware lock on the bus
- * @pm_runtime_disabled: true if pm runtime is disabled
+ * @pm_disabled: true if power-management should be disabled for this i2c-bus
*
* HCNT and LCNT parameters can be used if the platform knows more accurate
* values than the one computed based only on the input clock frequency.
@@ -127,7 +127,7 @@ struct dw_i2c_dev {
struct pm_qos_request pm_qos;
int (*acquire_lock)(struct dw_i2c_dev *dev);
void (*release_lock)(struct dw_i2c_dev *dev);
- bool pm_runtime_disabled;
+ bool pm_disabled;
bool dynamic_tar_update_enabled;
};

diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index df0ff7d..8ed96dd 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -276,7 +276,7 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
adap->dev.of_node = pdev->dev.of_node;

- if (dev->pm_runtime_disabled) {
+ if (dev->pm_disabled) {
pm_runtime_forbid(&pdev->dev);
} else {
pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
@@ -286,7 +286,7 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
}

r = i2c_dw_probe(dev);
- if (r && !dev->pm_runtime_disabled)
+ if (r && !dev->pm_disabled)
pm_runtime_disable(&pdev->dev);

return r;
@@ -304,7 +304,7 @@ static int dw_i2c_plat_remove(struct platform_device *pdev)

pm_runtime_dont_use_autosuspend(&pdev->dev);
pm_runtime_put_sync(&pdev->dev);
- if (!dev->pm_runtime_disabled)
+ if (!dev->pm_disabled)
pm_runtime_disable(&pdev->dev);

i2c_dw_remove_lock_support(dev);
@@ -354,9 +354,7 @@ static int dw_i2c_plat_resume(struct device *dev)
struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);

i2c_dw_plat_prepare_clk(i_dev, true);
-
- if (!i_dev->pm_runtime_disabled)
- i2c_dw_init(i_dev);
+ i2c_dw_init(i_dev);

return 0;
}
--
2.9.3