[PATCH 6.8 222/336] hsr: Simplify code for announcing HSR nodes timer setup

Greg Kroah-Hartman
2024-05-14T10:44:27Z

From: Lukasz Majewski <lukma@denx.de>

[ Upstream commit 4893b8b3ef8db2b182d1a1bebf6c7acf91405000 ]

Up till now the code to start HSR announce timer, which triggers sending
supervisory frames, was assuming that hsr_netdev_notify() would be called
at least twice for hsrX interface. This was required to have different
values for old and current values of network device's operstate.

This is problematic for a case where hsrX interface is already in the
operational state when hsr_netdev_notify() is called, so timer is not
configured to trigger and as a result the hsrX is not sending supervisory
frames to HSR ring.

This error has been discovered when hsr_ping.sh script was run. To be
more specific - for the hsr1 and hsr2 the hsr_netdev_notify() was
called at least twice with different IF_OPER_{LOWERDOWN|DOWN|UP} states
assigned in hsr_check_carrier_and_operstate(hsr). As a result there was
no issue with sending supervisory frames.
However, with hsr3, the notify function was called only once with
operstate set to IF_OPER_UP and timer responsible for triggering
supervisory frames was not fired.

The solution is to use netif_oper_up() and netif_running() helper
functions to assess if network hsrX device is up.
Only then, when the timer is not already pending, it is started.
Otherwise it is deactivated.

Fixes: f421436a591d ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)")
Signed-off-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240507111214.3519800-1-lukma@denx.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/hsr/hsr_device.c | 27 ++++++++++++---------------
1 file changed, 12 insertions(+), 15 deletions(-)

diff --git a/net/hsr/hsr_device.c b/net/hsr/hsr_device.c
index be0e43f46556e..03a42de7511e8 100644
--- a/net/hsr/hsr_device.c
+++ b/net/hsr/hsr_device.c
@@ -71,39 +71,36 @@ static bool hsr_check_carrier(struct hsr_port *master)
return false;
}

-static void hsr_check_announce(struct net_device *hsr_dev,
- unsigned char old_operstate)
+static void hsr_check_announce(struct net_device *hsr_dev)
{
struct hsr_priv *hsr;

hsr = netdev_priv(hsr_dev);
-
- if (READ_ONCE(hsr_dev->operstate) == IF_OPER_UP && old_operstate != IF_OPER_UP) {
- /* Went up */
- hsr->announce_count = 0;
- mod_timer(&hsr->announce_timer,
- jiffies + msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL));
+ if (netif_running(hsr_dev) && netif_oper_up(hsr_dev)) {
+ /* Enable announce timer and start sending supervisory frames */
+ if (!timer_pending(&hsr->announce_timer)) {
+ hsr->announce_count = 0;
+ mod_timer(&hsr->announce_timer, jiffies +
+ msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL));
+ }
+ } else {
+ /* Deactivate the announce timer */
+ timer_delete(&hsr->announce_timer);
}
-
- if (READ_ONCE(hsr_dev->operstate) != IF_OPER_UP && old_operstate == IF_OPER_UP)
- /* Went down */
- del_timer(&hsr->announce_timer);
}

void hsr_check_carrier_and_operstate(struct hsr_priv *hsr)
{
struct hsr_port *master;
- unsigned char old_operstate;
bool has_carrier;

master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
/* netif_stacked_transfer_operstate() cannot be used here since
* it doesn't set IF_OPER_LOWERLAYERDOWN (?)
*/
- old_operstate = READ_ONCE(master->dev->operstate);
has_carrier = hsr_check_carrier(master);
hsr_set_operstate(master, has_carrier);
- hsr_check_announce(master->dev, old_operstate);
+ hsr_check_announce(master->dev);
}

int hsr_get_max_mtu(struct hsr_priv *hsr)
--
2.43.0