This is a note to let you know that I've just added the patch titled
lan966x: Fix unloading/loading of the driver
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
lan966x-fix-unloading-loading-of-the-driver.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 600761245952d7f70280add6ce02894f1528992b Mon Sep 17 00:00:00 2001
From: Horatiu Vultur <horatiu.vultur@xxxxxxxxxxxxx>
Date: Mon, 22 May 2023 14:00:38 +0200
Subject: lan966x: Fix unloading/loading of the driver
From: Horatiu Vultur <horatiu.vultur@xxxxxxxxxxxxx>
commit 600761245952d7f70280add6ce02894f1528992b upstream.
It was noticing that after a while when unloading/loading the driver and
sending traffic through the switch, it would stop working. It would stop
forwarding any traffic and the only way to get out of this was to do a
power cycle of the board. The root cause seems to be that the switch
core is initialized twice. Apparently initializing twice the switch core
disturbs the pointers in the queue systems in the HW, so after a while
it would stop sending the traffic.
Unfortunetly, it is not possible to use a reset of the switch here,
because the reset line is connected to multiple devices like MDIO,
SGPIO, FAN, etc. So then all the devices will get reseted when the
network driver will be loaded.
So the fix is to check if the core is initialized already and if that is
the case don't initialize it again.
Fixes: db8bcaad5393 ("net: lan966x: add the basic lan966x driver")
Signed-off-by: Horatiu Vultur <horatiu.vultur@xxxxxxxxxxxxx>
Reviewed-by: Simon Horman <simon.horman@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230522120038.3749026-1-horatiu.vultur@xxxxxxxxxxxxx
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/microchip/lan966x/lan966x_main.c | 10 ++++++++++
1 file changed, 10 insertions(+)
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
@@ -987,6 +987,16 @@ static int lan966x_reset_switch(struct l
reset_control_reset(switch_reset);
+ /* Don't reinitialize the switch core, if it is already initialized. In
+ * case it is initialized twice, some pointers inside the queue system
+ * in HW will get corrupted and then after a while the queue system gets
+ * full and no traffic is passing through the switch. The issue is seen
+ * when loading and unloading the driver and sending traffic through the
+ * switch.
+ */
+ if (lan_rd(lan966x, SYS_RESET_CFG) & SYS_RESET_CFG_CORE_ENA)
+ return 0;
+
lan_wr(SYS_RESET_CFG_CORE_ENA_SET(0), lan966x, SYS_RESET_CFG);
lan_wr(SYS_RAM_INIT_RAM_INIT_SET(1), lan966x, SYS_RAM_INIT);
ret = readx_poll_timeout(lan966x_ram_init, lan966x,
Patches currently in stable-queue which might be from horatiu.vultur@xxxxxxxxxxxxx are
queue-6.1/lan966x-fix-unloading-loading-of-the-driver.patch
