2024-05-07 11:41:39

by Lukasz Majewski

[permalink] [raw]
Subject: [net PATCH v2] hsr: Simplify code for announcing HSR nodes timer setup

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.

Signed-off-by: Lukasz Majewski <[email protected]>

Fixes: f421436a591d ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)")
---
Changes for v2:

- Add extra condition to check if the hsr network device is running
(not only up).

- Only start announce timer when it is not pending (to avoid period
shortening/violation)
---
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 e9d45133d641..5afc450d0855 100644
--- a/net/hsr/hsr_device.c
+++ b/net/hsr/hsr_device.c
@@ -61,39 +61,36 @@ 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)
--
2.20.1



2024-05-08 10:17:00

by Simon Horman

[permalink] [raw]
Subject: Re: [net PATCH v2] hsr: Simplify code for announcing HSR nodes timer setup

On Tue, May 07, 2024 at 01:12:14PM +0200, Lukasz Majewski wrote:
> 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.
>
> Signed-off-by: Lukasz Majewski <[email protected]>
>
> Fixes: f421436a591d ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)")
> ---
> Changes for v2:
>
> - Add extra condition to check if the hsr network device is running
> (not only up).
>
> - Only start announce timer when it is not pending (to avoid period
> shortening/violation)

Reviewed-by: Simon Horman <[email protected]>


2024-05-09 02:00:53

by patchwork-bot+netdevbpf

[permalink] [raw]
Subject: Re: [net PATCH v2] hsr: Simplify code for announcing HSR nodes timer setup

Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <[email protected]>:

On Tue, 7 May 2024 13:12:14 +0200 you wrote:
> 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.
>
> [...]

Here is the summary with links:
- [net,v2] hsr: Simplify code for announcing HSR nodes timer setup
https://git.kernel.org/netdev/net/c/4893b8b3ef8d

You are awesome, thank you!
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