From: Jan Kiszka <jan.kiszka@siemens.com>
To: Wim Van Sebroeck <wim@linux-watchdog.org>,
Guenter Roeck <linux@roeck-us.net>
Cc: linux-watchdog@vger.kernel.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Tero Kristo <t-kristo@ti.com>,
"Su, Bao Cheng (RC-CN DF FA R&D)" <baocheng.su@siemens.com>
Subject: [RFC][PATCH] watchdog: rti-wdt: Provide set_timeout handler to make existing userspace happy
Date: Mon, 13 Sep 2021 13:41:43 +0200 [thread overview]
Message-ID: <4d82b8ce-bc34-e4b2-c5fe-9e883b0db59d@siemens.com> (raw)
From: Jan Kiszka <jan.kiszka@siemens.com>
Prominent userspace - systemd - cannot handle watchdogs without
WDIOF_SETTIMEOUT, even if it was configured to the same time as the
driver selected or was used by firmware to start the watchdog. To avoid
failing in this case, implement a handler that only fails if a deviating
set_timeout is requested.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
See also https://github.com/systemd/systemd/issues/20683
drivers/watchdog/rti_wdt.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c
index 359302f71f7e..365255b15a0d 100644
--- a/drivers/watchdog/rti_wdt.c
+++ b/drivers/watchdog/rti_wdt.c
@@ -173,13 +173,27 @@ static unsigned int rti_wdt_get_timeleft_ms(struct watchdog_device *wdd)
return timer_counter;
}
+static int rti_wdt_set_timeout(struct watchdog_device *wdd,
+ unsigned int timeout)
+{
+ /*
+ * Updating the timeout after start is actually not supported, but
+ * let's ignore requests for the already configured value. Helps
+ * existing userspace such as systemd.
+ */
+ if (timeout != heartbeat)
+ return -EOPNOTSUPP;
+
+ return 0;
+}
+
static unsigned int rti_wdt_get_timeleft(struct watchdog_device *wdd)
{
return rti_wdt_get_timeleft_ms(wdd) / 1000;
}
static const struct watchdog_info rti_wdt_info = {
- .options = WDIOF_KEEPALIVEPING,
+ .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT,
.identity = "K3 RTI Watchdog",
};
@@ -187,6 +201,7 @@ static const struct watchdog_ops rti_wdt_ops = {
.owner = THIS_MODULE,
.start = rti_wdt_start,
.ping = rti_wdt_ping,
+ .set_timeout = rti_wdt_set_timeout,
.get_timeleft = rti_wdt_get_timeleft,
};
--
2.31.1
next reply other threads:[~2021-09-13 11:42 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-13 11:41 Jan Kiszka [this message]
2021-09-13 14:37 ` [RFC][PATCH] watchdog: rti-wdt: Provide set_timeout handler to make existing userspace happy Guenter Roeck
2024-04-21 8:49 ` Francesco Dolcini
2024-04-22 5:35 ` Jan Kiszka
2024-04-22 8:20 ` Francesco Dolcini
2024-04-22 8:23 ` Francesco Dolcini
2024-04-21 23:50 ` Guenter Roeck
2024-04-22 5:36 ` Jan Kiszka
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4d82b8ce-bc34-e4b2-c5fe-9e883b0db59d@siemens.com \
--to=jan.kiszka@siemens.com \
--cc=baocheng.su@siemens.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-watchdog@vger.kernel.org \
--cc=linux@roeck-us.net \
--cc=t-kristo@ti.com \
--cc=wim@linux-watchdog.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).