Re: [PATCH] rtc: imxdi: add wakeup support

From: Martin Kaiser <martin@kaiser.cx>
To: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>,
	Shawn Guo <shawnguo@kernel.org>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	Fabio Estevam <festevam@gmail.com>,
	linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org,
	Stephen Boyd <sboyd@kernel.org>
Subject: Re: [PATCH] rtc: imxdi: add wakeup support
Date: Wed, 5 May 2021 18:25:22 +0200	[thread overview]
Message-ID: <20210505162522.whho2nbqtxof62zk@viti.kaiser.cx> (raw)
In-Reply-To: <YJE6QhePvy7f4LKW@piout.net>

Hi Alexandre,

thanks for the quick reply.

Thus wrote Alexandre Belloni (alexandre.belloni@bootlin.com):

> Doesn't everyone expect the RTC to be a wakeup source? :)

Ok, I'll change this.

> > What is the right approach here? Are there any rtc drivers that act as a
> > wakeup source and can still be unloaded if compiled as a module?

> Yes, when you don't have alarmtimer ;)
> I honestly think the RTC selection needs to be a bit more dynamic but at
> the same time, it would not be great to change it at suspend time. I
> guess the best way would be to allow module unloading and tracking when
> the RTC disappears.

Ok, understood. There's no chance to address this in an rtc driver.

Out of curiousity, I tried adding a .remove_dev function in alarmtimer.
It isn't called when the I try to unload the rtc-imxdi module. It seems
that the module layer checks the refcount and returns an error before we
even attempt to remove the rtc device...

Best regards,
Martin