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authorHoratiu Vultur <horatiu.vultur@microchip.com>2023-05-22 15:00:38 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-05-30 16:03:21 +0300
commit9bc1dbfd9158c53b11c458559381998c04e8c240 (patch)
tree60e2adff471c837a0120c43f0b020664a188629e
parent1a9e80f757bbb1562d82e350afce2bb2f712cc3d (diff)
downloadlinux-9bc1dbfd9158c53b11c458559381998c04e8c240.tar.xz
lan966x: Fix unloading/loading of the driver
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@microchip.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Link: https://lore.kernel.org/r/20230522120038.3749026-1-horatiu.vultur@microchip.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/net/ethernet/microchip/lan966x/lan966x_main.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
index 569108c49cbc..9ce46588aaf0 100644
--- 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 lan966x *lan966x)
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,