linux-kernel - [Query]: Resource cleanup for Alarmtimer

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Date:   Wed, 20 Sep 2023 08:12:10 +0000
From:   Biju Das <biju.das.jz@...renesas.com>
To:     Thomas Gleixner <tglx@...utronix.de>,
        John Stultz <jstultz@...gle.com>,
        Stephen Boyd <sboyd@...nel.org>,
        Alexandre Belloni <alexandre.belloni@...tlin.com>,
        Geert Uytterhoeven <geert+renesas@...der.be>
CC:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        John Stultz <jstultz@...gle.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Stephen Boyd <sboyd@...nel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Biju Das <biju.das.au@...il.com>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        "linux-rtc@...r.kernel.org" <linux-rtc@...r.kernel.org>,
        "linux-renesas-soc@...r.kernel.org" 
        <linux-renesas-soc@...r.kernel.org>,
        Trent Piepho <tpiepho@...il.com>
Subject: [Query]: Resource cleanup for Alarmtimer

Hi All,

Currently unbind/bind is not working as expected on rtc-isl1208 driver. The reason is put_device() is not calling rtc_device_release()
as some of the kobjects are not freed during unbind.

The commit 	c79108bd19a8 "alarmtimer: Make alarmtimer platform device child of RTC device" adds kobjects for alarmtimer device/sysfs, when we call device_init_wakeup() followed by devm_rtc_register_device()from the end point driver during probe().
But these kobjects are never freed when we do unbind on the endpoint driver.

The alarm timer device has alarmtimer_rtc_add_device() but it does not have remove_device() callbacks to free kbjects.

Q1) Has anyone tested unbind/rebind on RTC subsystem with device_init_wakeup() followed by devm_rtc_register_device() in
the probe?

Cheers,
Biju