i2c: i801: Stop using pm_runtime_set_autosuspend_delay(-1)

The original change works as intended, but Andy pointed in [0] that now
userspace could re-enable RPM via sysfs, even though we explicitly want
to disable it. So effectively revert the original patch, just with small
improvements:
- Calls to pm_runtime_allow()/pm_runtime_forbid() don't have to be
  balanced, so we can remove the call to pm_runtime_forbid() in
  i801_remove().
- priv->acpi_reserved is accessed after i801_acpi_remove(), and according
  to Robert [1] the custom handler can't run any longer. Therefore we
  don't have to take priv->acpi_lock.

[0] https://www.spinics.net/lists/linux-i2c/msg52730.html
[1] https://lore.kernel.org/linux-acpi/BYAPR11MB32561D19A0FD9AB93E2B1E5287D39@BYAPR11MB3256.namprd11.prod.outlook.com/T/#t

Fixes: 4e60d5dd10cd ("i2c: i801: Improve disabling runtime pm")
Reported-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index 260fc41..115660d 100644 (file)
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -1615,7 +1615,7 @@ i801_acpi_io_handler(u32 function, acpi_physical_address address, u32 bits,
                 * BIOS is accessing the host controller so prevent it from
                 * suspending automatically from now on.
                 */
-               pm_runtime_set_autosuspend_delay(&pdev->dev, -1);
+               pm_runtime_get_sync(&pdev->dev);
        }
 
        if ((function & ACPI_IO_MASK) == ACPI_READ)
@@ -1866,9 +1866,6 @@ static void i801_remove(struct pci_dev *dev)
 {
        struct i801_priv *priv = pci_get_drvdata(dev);
 
-       pm_runtime_forbid(&dev->dev);
-       pm_runtime_get_noresume(&dev->dev);
-
        i801_disable_host_notify(priv);
        i801_del_mux(priv);
        i2c_del_adapter(&priv->adapter);
@@ -1877,6 +1874,10 @@ static void i801_remove(struct pci_dev *dev)
 
        platform_device_unregister(priv->tco_pdev);
 
+       /* if acpi_reserved is set then usage_count is incremented already */
+       if (!priv->acpi_reserved)
+               pm_runtime_get_noresume(&dev->dev);
+
        /*
         * do not call pci_disable_device(dev) since it can cause hard hangs on
         * some systems during power-off (eg. Fujitsu-Siemens Lifebook E8010)