Wilczynski, Michal wrote:
>
>
> On 6/29/2023 10:54 PM, Dan Williams wrote:
> > Michal Wilczynski wrote:
> >> Currently logic for installing notifications from ACPI devices is
> >> implemented using notify callback in struct acpi_driver. Preparations
> >> are being made to replace acpi_driver with more generic struct
> >> platform_driver, which doesn't contain notify callback. Furthermore
> >> as of now handlers are being called indirectly through
> >> acpi_notify_device(), which decreases performance.
> >>
> >> Call acpi_dev_install_notify_handler() at the end of .add() callback.
> >> Call acpi_dev_remove_notify_handler() at the beginning of .remove()
> >> callback. Change arguments passed to the notify function to match with
> >> what's required by acpi_install_notify_handler(). Remove .notify
> >> callback initialization in acpi_driver.
> >>
> >> Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> >> Signed-off-by: Michal Wilczynski <michal.wilczynski@xxxxxxxxx>
> >> ---
> >> drivers/acpi/nfit/core.c | 24 ++++++++++++++++++------
> >> 1 file changed, 18 insertions(+), 6 deletions(-)
> >>
> >> diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
> >> index 95930e9d776c..a281bdfee8a0 100644
> >> --- a/drivers/acpi/nfit/core.c
> >> +++ b/drivers/acpi/nfit/core.c
> >> @@ -3312,11 +3312,13 @@ void acpi_nfit_shutdown(void *data)
> >> }
> >> EXPORT_SYMBOL_GPL(acpi_nfit_shutdown);
> >>
> >> -static void acpi_nfit_notify(struct acpi_device *adev, u32 event)
> >> +static void acpi_nfit_notify(acpi_handle handle, u32 event, void *data)
> >> {
> >> - device_lock(&adev->dev);
> >> - __acpi_nfit_notify(&adev->dev, adev->handle, event);
> >> - device_unlock(&adev->dev);
> >> + struct acpi_device *device = data;
> >> +
> >> + device_lock(&device->dev);
> >> + __acpi_nfit_notify(&device->dev, handle, event);
> >> + device_unlock(&device->dev);
> >> }
> >>
> >> static int acpi_nfit_add(struct acpi_device *adev)
> >> @@ -3375,12 +3377,23 @@ static int acpi_nfit_add(struct acpi_device *adev)
> >>
> >> if (rc)
> >> return rc;
> >> - return devm_add_action_or_reset(dev, acpi_nfit_shutdown, acpi_desc);
> >> +
> >> + rc = devm_add_action_or_reset(dev, acpi_nfit_shutdown, acpi_desc);
> >> + if (rc)
> >> + return rc;
> >> +
> >> + return acpi_dev_install_notify_handler(adev,
> >> + ACPI_DEVICE_NOTIFY,
> >> + acpi_nfit_notify);
> >> }
> >>
> >> static void acpi_nfit_remove(struct acpi_device *adev)
> >> {
> >> /* see acpi_nfit_unregister */
> >> +
> >> + acpi_dev_remove_notify_handler(adev,
> >> + ACPI_DEVICE_NOTIFY,
> >> + acpi_nfit_notify);
> > Please use devm to trigger this release rather than making
> > acpi_nfit_remove() contain any logic.
>
> I think adding separate devm action to remove event handler is not
> necessary. I'll put the removal in the beggining of acpi_nfit_shutdown() if you
> don't object.
How do you plan to handle an acpi_dev_install_notify_handler() failure?
acpi_nfit_shutdown() will need to have extra logic to know that it can
skip acpi_dev_remove_notify_handler() in some cases and not other..
Maybe it is ok to remove a handler that was never installed, but I would
rather not go look that up. A devm callback for
acpi_dev_remove_notify_handler() avoids that.
