On 31.08.2021 13:26, Jean Delvare wrote: > On Tue, 31 Aug 2021 08:05:41 +0200, Heiner Kallweit wrote: >> On 26.08.2021 16:00, Jean Delvare wrote: >>> If pm_runtime_set_autosuspend_delay() is not suitable for the task then >>> maybe we need a better API. I will admit I'm at a loss when it comes to >>> the many pm_runtime_* calls, I'm not going to claim I fully understand >>> what each of them is doing exactly. But don't we want to simply call >>> pm_runtime_dont_use_autosuspend() here? >>> >>> If not and there's no suitable API for the task at the moment, then >>> better do not apply this patch, and instead ask the PM subsystem >>> maintainers if they would be willing to implement what we need. >> >> To follow-up on this: This patch has been applied already. Therefore, >> if decision is to not go with it, it would need to be reverted. > > Technically it's not in Linus' tree yet ;-) > > I'm still interested to know if pm_runtime_dont_use_autosuspend() is > the right call to use in this situation. > I don't think so. It disable auto-suspending, but leaves "normal" runtime-suspending active. Calling pm_runtime_disable() may be an alternative. Or we use the following to re-establish the old behavior with a little less overhead. Getting the mutex isn't needed here because the PCI core increments the rpm usage_count before calling the remove() hook. diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c index 1f929e6c3..b5723d946 100644 --- a/drivers/i2c/busses/i2c-i801.c +++ b/drivers/i2c/busses/i2c-i801.c @@ -1623,7 +1623,7 @@ 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) @@ -1891,7 +1891,9 @@ 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); + /* if acpi_reserved is set then usage_count is incremented already */ + if (!priv->acpi_reserved) + pm_runtime_get_noresume(&dev->dev); i801_disable_host_notify(priv); i801_del_mux(priv); -- 2.33.0
