Bug 216600

I meant the v6.1-rc1 release, sorry for the type in the first line.

It looks like the offending commit is this, adding Raphael to the CC list:

commit 4919d3eb2ec0ee364f7e3cf2d99646c1b224fae8
Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Date:   Wed Oct 12 20:07:01 2022 +0200

    rtc: cmos: Fix event handler registration ordering issue
    
    Because acpi_install_fixed_event_handler() enables the event
    automatically on success, it is incorrect to call it before the
    handler routine passed to it is ready to handle events.
    
    Unfortunately, the rtc-cmos driver does exactly the incorrect thing
    by calling cmos_wake_setup(), which passes rtc_handler() to
    acpi_install_fixed_event_handler(), before cmos_do_probe(), because
    rtc_handler() uses dev_get_drvdata() to get to the cmos object
    pointer and the driver data pointer is only populated in
    cmos_do_probe().
    
    This leads to a NULL pointer dereference in rtc_handler() on boot
    if the RTC fixed event happens to be active at the init time.
    
    To address this issue, change the initialization ordering of the
    driver so that cmos_wake_setup() is always called after a successful
    cmos_do_probe() call.
    
    While at it, change cmos_pnp_probe() to call cmos_do_probe() after
    the initial if () statement used for computing the IRQ argument to
    be passed to cmos_do_probe() which is cleaner than calling it in
    each branch of that if () (local variable "irq" can be of type int,
    because it is passed to that function as an argument of type int).
    
    Note that commit 6492fed7d8c9 ("rtc: rtc-cmos: Do not check
    ACPI_FADT_LOW_POWER_S0") caused this issue to affect a larger number
    of systems, because previously it only affected systems with
    ACPI_FADT_LOW_POWER_S0 set, but it is present regardless of that
    commit.
    
    Fixes: 6492fed7d8c9 ("rtc: rtc-cmos: Do not check ACPI_FADT_LOW_POWER_S0")
    Fixes: a474aaedac99 ("rtc-cmos: move wake setup from ACPI glue into RTC driver")
    Link: https://lore.kernel.org/linux-acpi/20221010141630.zfzi7mk7zvnmclzy@techsingularity.net/
    Reported-by: Mel Gorman <mgorman@techsingularity.net>
    Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
    Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>
    Tested-by: Mel Gorman <mgorman@techsingularity.net>
    Link: https://lore.kernel.org/r/5629262.DvuYhMxLoT@kreacher
    Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

This seems to be introduced by commit
commit 4919d3eb2ec0ee364f7e3cf2d99646c1b224fae8
Author:     Rafael J. Wysocki <rafael.j.wysocki@intel.com>
AuthorDate: Wed Oct 12 20:07:01 2022 +0200
Commit:     Alexandre Belloni <alexandre.belloni@bootlin.com>
CommitDate: Thu Oct 13 23:27:52 2022 +0200

    rtc: cmos: Fix event handler registration ordering issue


with the commit, the rtc device is registered (cmos_do_probe()) before wakeup-capability enabled in cmos_wake_setup(), thus "wakealarm" attribute is not created because rtc_does_wakealarm() returns failure.

I have confirmed the workaround below can bring the wakealarm attribute back.

diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index 343f31ab7a01..76a5c7d968a4 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -1368,6 +1368,7 @@ static int cmos_pnp_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
                irq = pnp_irq(pnp, 0);
        }

+       device_init_wakeup(&pnp->dev, 1);
        ret = cmos_do_probe(&pnp->dev, pnp_get_resource(pnp, IORESOURCE_IO, 0), irq);
        if (ret)

TWIMC and for proper Link: and reported-by tags, there afaics is another report about this issue here: https://lore.kernel.org/all/87edv6mlow.fsf@kernel.org/

Created attachment 303029 [details]
[PATCH] Revert "rtc: cmos: Fix event handler registration ordering issue"

The change in comment #3 did not work for me,
but the revert (attached) does work for me.

Should be fixed by:

https://lore.kernel.org/linux-acpi/5887691.lOV4Wx5bFT@kreacher/

Just tested Raphael's patch, it appears to work on the 6 machines I've tried.

This patch still does not appear in 6.1.0-rc2, so I'm keeping it open until it actually makes it into the upstream kernel.

I just verified the fix has made it into 6.1-rc3. This bug is now closed.