Lock the adapter while setting the suspended flag, to ensure that other
locked code always sees the change immediately, rather then possibly using
a stale value.
This involves splitting the suspend/resume callbacks into separate runtime
and normal suspend/resume calls. This is necessary because i2c_dw_xfer()
will get called by the i2c-core with the adapter locked and it in turn
calls the runtime-resume callback through pm_runtime_get_sync().
So the runtime versions of the suspend/resume callbacks cannot take
the adapter-lock. Note this patch simply makes the runtime suspend/resume
callbacks not deal with the suspended flag at all. During runtime the
pm_runtime_get_sync() from i2c_dw_xfer() will always ensure that the
adapter is resumed when necessary.
The suspended flag check is only necessary to check proper suspend/resume
ordering during normal suspend/resume which makes the pm_runtime_get_sync()
call a no-op.
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
drivers/i2c/busses/i2c-designware-pcidrv.c | 31 +++++++++++++++++----
drivers/i2c/busses/i2c-designware-platdrv.c | 31 +++++++++++++++++----
2 files changed, 52 insertions(+), 10 deletions(-)
diff --git a/drivers/i2c/busses/i2c-designware-pcidrv.c b/drivers/i2c/busses/i2c-designware-pcidrv.c
index ef4250f8852b..9553d7075223 100644
--- a/drivers/i2c/busses/i2c-designware-pcidrv.c
+++ b/drivers/i2c/busses/i2c-designware-pcidrv.c
@@ -213,14 +213,30 @@ static struct dw_pci_controller dw_pci_controllers[] = {
},
};
+static int __maybe_unused i2c_dw_pci_runtime_suspend(struct device *dev)
+{
+ struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
+
+ i_dev->disable(i_dev);
+ return 0;
+}
+
static int __maybe_unused i2c_dw_pci_suspend(struct device *dev)
{
struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
+ i2c_lock_bus(&i_dev->adapter, I2C_LOCK_ROOT_ADAPTER);
i_dev->suspended = true;
- i_dev->disable(i_dev);
+ i2c_unlock_bus(&i_dev->adapter, I2C_LOCK_ROOT_ADAPTER);
- return 0;
+ return i2c_dw_pci_runtime_suspend(dev);
+}
+
+static int __maybe_unused i2c_dw_pci_runtime_resume(struct device *dev)
+{
+ struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
+
+ return i_dev->init(i_dev);
}
static int __maybe_unused i2c_dw_pci_resume(struct device *dev)
@@ -228,14 +244,19 @@ static int __maybe_unused i2c_dw_pci_resume(struct device *dev)
struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
int ret;
- ret = i_dev->init(i_dev);
+ ret = i2c_dw_pci_runtime_resume(dev);
+
+ i2c_lock_bus(&i_dev->adapter, I2C_LOCK_ROOT_ADAPTER);
i_dev->suspended = false;
+ i2c_unlock_bus(&i_dev->adapter, I2C_LOCK_ROOT_ADAPTER);
return ret;
}
-static UNIVERSAL_DEV_PM_OPS(i2c_dw_pm_ops, i2c_dw_pci_suspend,
- i2c_dw_pci_resume, NULL);
+static const struct dev_pm_ops i2c_dw_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(i2c_dw_pci_suspend, i2c_dw_pci_resume)
+ SET_RUNTIME_PM_OPS(i2c_dw_pci_runtime_suspend, i2c_dw_pci_runtime_resume, NULL)
+};
static int i2c_dw_pci_probe(struct pci_dev *pdev,
const struct pci_device_id *id)
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 2bd81abc86f6..8e45f65bab73 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -368,12 +368,10 @@ static void dw_i2c_plat_complete(struct device *dev)
#endif
#ifdef CONFIG_PM
-static int dw_i2c_plat_suspend(struct device *dev)
+static int dw_i2c_plat_runtime_suspend(struct device *dev)
{
struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
- i_dev->suspended = true;
-
if (i_dev->shared_with_punit)
return 0;
@@ -383,7 +381,18 @@ static int dw_i2c_plat_suspend(struct device *dev)
return 0;
}
-static int dw_i2c_plat_resume(struct device *dev)
+static int dw_i2c_plat_suspend(struct device *dev)
+{
+ struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
+
+ i2c_lock_bus(&i_dev->adapter, I2C_LOCK_ROOT_ADAPTER);
+ i_dev->suspended = true;
+ i2c_unlock_bus(&i_dev->adapter, I2C_LOCK_ROOT_ADAPTER);
+
+ return dw_i2c_plat_runtime_suspend(dev);
+}
+
+static int dw_i2c_plat_runtime_resume(struct device *dev)
{
struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
@@ -391,7 +400,19 @@ static int dw_i2c_plat_resume(struct device *dev)
i2c_dw_prepare_clk(i_dev, true);
i_dev->init(i_dev);
+
+ return 0;
+}
+
+static int dw_i2c_plat_resume(struct device *dev)
+{
+ struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
+
+ dw_i2c_plat_runtime_resume(dev);
+
+ i2c_lock_bus(&i_dev->adapter, I2C_LOCK_ROOT_ADAPTER);
i_dev->suspended = false;
+ i2c_unlock_bus(&i_dev->adapter, I2C_LOCK_ROOT_ADAPTER);
return 0;
}
@@ -400,7 +421,7 @@ static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
.prepare = dw_i2c_plat_prepare,
.complete = dw_i2c_plat_complete,
SET_LATE_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
- SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL)
+ SET_RUNTIME_PM_OPS(dw_i2c_plat_runtime_suspend, dw_i2c_plat_runtime_resume, NULL)
};
#define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
--
2.35.1
