Hello Pierre,
On Tue, Mar 07, 2023 at 02:31:49PM -0500, Pierre Asselin wrote:
> > Maybe the following patch helps (on top of v6.3-rc1):
> >
> > diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
> > index 9531dd0fef50..a5a8f82981ce 100644
> > --- a/drivers/acpi/bus.c
> > +++ b/drivers/acpi/bus.c
> > @@ -518,7 +518,7 @@ static void acpi_bus_notify(acpi_handle handle, u32
> > type, void *data)
> > if (!adev)
> > goto err;
> >
> > - if (adev->dev.driver) {
> > + if (device_is_bound(&adev->dev)) {
> > struct acpi_driver *driver = to_acpi_driver(adev->dev.driver);
> >
> > if (driver && driver->ops.notify &&
> >
>
> It does indeed "fix" 6.3-rc1. Modulo locking issues, which I am
> not qualified to evaluate.
Thanks for your prompt test feedback.
The locked variant could look as follows:
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 9531dd0fef50..fddca263ac40 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -518,13 +518,15 @@ static void acpi_bus_notify(acpi_handle handle, u32 type, void *data)
if (!adev)
goto err;
- if (adev->dev.driver) {
+ device_lock(&adev->dev);
+ if (device_is_bound(&adev->dev)) {
struct acpi_driver *driver = to_acpi_driver(adev->dev.driver);
if (driver && driver->ops.notify &&
(driver->flags & ACPI_DRIVER_ALL_NOTIFY_EVENTS))
driver->ops.notify(adev, type);
}
+ device_unlock(&adev->dev);
if (!hotplug_event) {
acpi_put_acpi_dev(adev);
Pierre: If you want to test that, I suggest to also enable
PROVE_LOCKING.
Rafael: I don't know if this would work and I hope you're able to judge
this better than I do. The change without the lock is for sure better
than the status quo.
I did a similar conversion as the blamed commit for pci that got
reverted for similiar reasons. See
68da4e0eaaab421f228eac57cbe7505b136464af. (Added Bjorn and Robert to
Cc:) I think the pci code suffers from a similar race even after
reverting my change. If someone is able to find the right fix for one of
them, that might be transferable to the other?!
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | https://www.pengutronix.de/ |
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