[v6,1/1] i2c: Restore initial power state if probe fails

Message ID 20221109-i2c-waive-v6-1-bc059fb7e8fa@chromium.org
State New
Headers
Series i2c: Restore power status of device if probe fails |

Commit Message

Ricardo Ribalda Nov. 14, 2022, 12:20 p.m. UTC
  A driver that supports I2C_DRV_ACPI_WAIVE_D0_PROBE is not expected to
power off a device that it has not powered on previously.

For devices operating in "full_power" mode, the first call to
`i2c_acpi_waive_d0_probe` will return 0, which means that the device
will be turned on with `dev_pm_domain_attach`.

If probe fails the second call to `i2c_acpi_waive_d0_probe` will
return 1, which means that the device will not be turned off.
This is, it will be left in a different power state. Lets fix it.

Reviewed-by: Hidenori Kobayashi <hidenorik@chromium.org>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: stable@vger.kernel.org
Fixes: b18c1ad685d9 ("i2c: Allow an ACPI driver to manage the device's power state during probe")
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
  

Comments

Mika Westerberg Nov. 14, 2022, 12:42 p.m. UTC | #1
On Mon, Nov 14, 2022 at 01:20:34PM +0100, Ricardo Ribalda wrote:
> A driver that supports I2C_DRV_ACPI_WAIVE_D0_PROBE is not expected to
> power off a device that it has not powered on previously.
> 
> For devices operating in "full_power" mode, the first call to
> `i2c_acpi_waive_d0_probe` will return 0, which means that the device
> will be turned on with `dev_pm_domain_attach`.
> 
> If probe fails the second call to `i2c_acpi_waive_d0_probe` will
> return 1, which means that the device will not be turned off.
> This is, it will be left in a different power state. Lets fix it.
> 
> Reviewed-by: Hidenori Kobayashi <hidenorik@chromium.org>
> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
> Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
  
Wolfram Sang Nov. 14, 2022, 7:47 p.m. UTC | #2
wOn Mon, Nov 14, 2022 at 01:20:34PM +0100, Ricardo Ribalda wrote:
> A driver that supports I2C_DRV_ACPI_WAIVE_D0_PROBE is not expected to
> power off a device that it has not powered on previously.
> 
> For devices operating in "full_power" mode, the first call to
> `i2c_acpi_waive_d0_probe` will return 0, which means that the device
> will be turned on with `dev_pm_domain_attach`.
> 
> If probe fails the second call to `i2c_acpi_waive_d0_probe` will
> return 1, which means that the device will not be turned off.
> This is, it will be left in a different power state. Lets fix it.
> 
> Reviewed-by: Hidenori Kobayashi <hidenorik@chromium.org>
> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
> Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> Cc: stable@vger.kernel.org
> Fixes: b18c1ad685d9 ("i2c: Allow an ACPI driver to manage the device's power state during probe")
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>

Applied to for-current, thanks!
  

Patch

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index b4edf10e8fd0..7539b0740351 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -467,6 +467,7 @@  static int i2c_device_probe(struct device *dev)
 {
 	struct i2c_client	*client = i2c_verify_client(dev);
 	struct i2c_driver	*driver;
+	bool do_power_on;
 	int status;
 
 	if (!client)
@@ -545,8 +546,8 @@  static int i2c_device_probe(struct device *dev)
 	if (status < 0)
 		goto err_clear_wakeup_irq;
 
-	status = dev_pm_domain_attach(&client->dev,
-				      !i2c_acpi_waive_d0_probe(dev));
+	do_power_on = !i2c_acpi_waive_d0_probe(dev);
+	status = dev_pm_domain_attach(&client->dev, do_power_on);
 	if (status)
 		goto err_clear_wakeup_irq;
 
@@ -585,7 +586,7 @@  static int i2c_device_probe(struct device *dev)
 err_release_driver_resources:
 	devres_release_group(&client->dev, client->devres_group_id);
 err_detach_pm_domain:
-	dev_pm_domain_detach(&client->dev, !i2c_acpi_waive_d0_probe(dev));
+	dev_pm_domain_detach(&client->dev, do_power_on);
 err_clear_wakeup_irq:
 	dev_pm_clear_wake_irq(&client->dev);
 	device_init_wakeup(&client->dev, false);
@@ -610,7 +611,7 @@  static void i2c_device_remove(struct device *dev)
 
 	devres_release_group(&client->dev, client->devres_group_id);
 
-	dev_pm_domain_detach(&client->dev, !i2c_acpi_waive_d0_probe(dev));
+	dev_pm_domain_detach(&client->dev, true);
 
 	dev_pm_clear_wake_irq(&client->dev);
 	device_init_wakeup(&client->dev, false);