Re: [PATCH v4] watchdog: qcom_wdt: set WDOG_HW_RUNNING bit when appropriate

From: Guenter Roeck <linux@roeck-us.net>
To: Robert Marko <robert.marko@sartura.hr>
Cc: Kathiravan T <kathirav@codeaurora.org>,
	Andy Gross <agross@kernel.org>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	wim@linux-watchdog.org,
	linux-arm-msm <linux-arm-msm@vger.kernel.org>,
	linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org,
	Luka Perkov <luka.perkov@sartura.hr>
Subject: Re: [PATCH v4] watchdog: qcom_wdt: set WDOG_HW_RUNNING bit when appropriate
Date: Mon, 30 Nov 2020 15:56:35 -0800	[thread overview]
Message-ID: <20201130235635.GA46844@roeck-us.net> (raw)
In-Reply-To: <CA+HBbNFtfNcGKC0Tv7cfeBO-4p_momdQ9fr1=1hEd4O2ieskfw@mail.gmail.com>

On Mon, Nov 30, 2020 at 07:27:00PM +0100, Robert Marko wrote:
> On Mon, Nov 2, 2020 at 6:19 AM Kathiravan T <kathirav@codeaurora.org> wrote:
> >
> >
> > On 11/2/2020 10:33 AM, Guenter Roeck wrote:
> > > On 11/1/20 7:58 PM, Kathiravan T wrote:
> > >> On 10/31/2020 7:38 PM, Guenter Roeck wrote:
> > >>> On 10/31/20 5:11 AM, Robert Marko wrote:
> > >>>> If the watchdog hardware is enabled/running during boot, e.g.
> > >>>> due to a boot loader configuring it, we must tell the
> > >>>> watchdog framework about this fact so that it can ping the
> > >>>> watchdog until userspace opens the device and takes over
> > >>>> control.
> > >>>>
> > >>>> Do so using the WDOG_HW_RUNNING flag that exists for exactly
> > >>>> that use-case.
> > >>>>
> > >>>> Signed-off-by: Robert Marko <robert.marko@sartura.hr>
> > >>> Reviewed-by: Guenter Roeck <linux@roeck-us.net>
> > >> Thanks for addressing the comments and now the patch looks good to me. One more suggestion, can we make the initcall level of the driver to subsys_initcall_sync so that the driver gets registered immediately after the watchdog_core is registered and watchdog_core starts pinging the WDT?
> > >>
> > > That would mean to replace module_platform_driver(), which would be a whole
> > > different discussion, is not widely needed, and would potentially interfere
> > > with the subsys_initcall_sync() in the watchdog core. This will require
> > > specific evidence that a problem is seen in the field, and that it is truly
> > > needed. Plus, it would have to be a different patch (which you could submit
> > > yourself, with evidence). Let's stick with one logical change per patch,
> > > please.
> > >
> > > Guenter
> > Yeah, of course I don't want to squash the initcall level change with
> > this one. Just made a suggestion to consider it. Anyway I will try to
> > collect some data and post the patch by own on that suggestion. Thanks
> > Guenter.
> >
> > --
> > QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
> >
> 
> Any chance this could be picked for 5.11?
> I have some boards depending on it for normal boot.
> 
It is queued in my watchdog-next branch, so Wim will most likely pick it up.

Guenter