From 244cff7066f6b517ef30bba757e1837d5b8b3aa7 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Tue, 30 May 2017 20:52:26 +0200 Subject: [PATCH] xen: don't print error message in case of missing Xenstore entry [ Upstream commit 4e93b6481c87ea5afde944a32b4908357ec58992 ] When registering for the Xenstore watch of the node control/sysrq the handler will be called at once. Don't issue an error message if the Xenstore node isn't there, as it will be created only when an event is being triggered. Signed-off-by: Juergen Gross Reviewed-by: Boris Ostrovsky Signed-off-by: Juergen Gross Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/xen/manage.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c index 357a8db859c9..9122ba25bb00 100644 --- a/drivers/xen/manage.c +++ b/drivers/xen/manage.c @@ -277,8 +277,16 @@ static void sysrq_handler(struct xenbus_watch *watch, const char **vec, err = xenbus_transaction_start(&xbt); if (err) return; - if (xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key) < 0) { - pr_err("Unable to read sysrq code in control/sysrq\n"); + err = xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key); + if (err < 0) { + /* + * The Xenstore watch fires directly after registering it and + * after a suspend/resume cycle. So ENOENT is no error but + * might happen in those cases. + */ + if (err != -ENOENT) + pr_err("Error %d reading sysrq code in control/sysrq\n", + err); xenbus_transaction_end(xbt, 1); return; } -- 2.17.1