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From: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
To: wim@linux-watchdog.org, linux@roeck-us.net, shawnguo@kernel.org
Cc: linux-watchdog@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, grzegorz.jaszczyk@linaro.org
Subject: [PATCH 0/2] introduce watchdog_dev_suspend/resume
Date: Tue, 15 Jun 2021 14:39:02 +0200	[thread overview]
Message-ID: <20210615123904.2568052-1-grzegorz.jaszczyk@linaro.org> (raw)

Hi All,

This patch-set fixes system hang which occurs when the ping worker fires after
wdog suspend and before wdog resume. This happens because the ping worker can
issue low-level ping while the wdog clk was disabled by the suspend routine
(accessing hw wdog registers while they are not fed by the clk).

To overcome this issue two patches were introduced. Patch #1 provides
watchdog_dev_suspend/resume function, which can be used in wdog drivers. First
function allows to cancel watchdog ping worker during suspend, preventing
watchdog_dev from issuing low-level ping and second one restores ping worker if
needed.

Patch #2 introduces relevant changes to imx2_wdt driver and takes advantage of
just introduced routines.

Grzegorz Jaszczyk (2):
  watchdog: introduce watchdog_dev_suspend/resume
  watchdog: imx2_wdg: notify wdog subsystem about wdog suspend/resume

 drivers/watchdog/imx2_wdt.c     | 20 ++++++++++----
 drivers/watchdog/watchdog_dev.c | 49 +++++++++++++++++++++++++++++++++
 include/linux/watchdog.h        |  2 ++
 3 files changed, 66 insertions(+), 5 deletions(-)

-- 
2.29.0


             reply	other threads:[~2021-06-15 12:39 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-15 12:39 Grzegorz Jaszczyk [this message]
2021-06-15 12:39 ` [PATCH 1/2] watchdog: introduce watchdog_dev_suspend/resume Grzegorz Jaszczyk
2021-06-15 14:18   ` Guenter Roeck
2021-06-16 13:59     ` Grzegorz Jaszczyk
2021-06-16 17:57       ` Guenter Roeck
2021-06-16 23:21   ` kernel test robot
2021-06-15 12:39 ` [PATCH 2/2] watchdog: imx2_wdg: notify wdog subsystem about wdog suspend/resume Grzegorz Jaszczyk

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