From 2ef957de4e2dbbd76fa56b2ac8629e859ae618a5 Mon Sep 17 00:00:00 2001 From: Tristram Ha Date: Tue, 18 Jun 2024 17:16:42 -0700 Subject: [PATCH] net: dsa: microchip: fix initial port flush problem [ Upstream commit ad53f5f54f351e967128edbc431f0f26427172cf ] The very first flush in any port will flush all learned addresses in all ports. This can be observed by unplugging the cable from one port while additional ports are connected and dumping the fdb entries. This problem is caused by the initially wrong value programmed to the REG_SW_LUE_CTRL_1 register. Setting SW_FLUSH_STP_TABLE and SW_FLUSH_MSTP_TABLE bits does not have an immediate effect. It is when ksz9477_flush_dyn_mac_table() is called then the SW_FLUSH_STP_TABLE bit takes effect and flushes all learned entries. After that call both bits are reset and so the next port flush will not cause such problem again. Fixes: b987e98e50ab ("dsa: add DSA switch driver for Microchip KSZ9477") Signed-off-by: Tristram Ha Link: https://patch.msgid.link/1718756202-2731-1-git-send-email-Tristram.Ha@microchip.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/dsa/microchip/ksz9477.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/net/dsa/microchip/ksz9477.c b/drivers/net/dsa/microchip/ksz9477.c index 83b7f2d5c1ea..353c41e031f1 100644 --- a/drivers/net/dsa/microchip/ksz9477.c +++ b/drivers/net/dsa/microchip/ksz9477.c @@ -174,10 +174,8 @@ int ksz9477_reset_switch(struct ksz_device *dev) SPI_AUTO_EDGE_DETECTION, 0); /* default configuration */ - ksz_read8(dev, REG_SW_LUE_CTRL_1, &data8); - data8 = SW_AGING_ENABLE | SW_LINK_AUTO_AGING | - SW_SRC_ADDR_FILTER | SW_FLUSH_STP_TABLE | SW_FLUSH_MSTP_TABLE; - ksz_write8(dev, REG_SW_LUE_CTRL_1, data8); + ksz_write8(dev, REG_SW_LUE_CTRL_1, + SW_AGING_ENABLE | SW_LINK_AUTO_AGING | SW_SRC_ADDR_FILTER); /* disable interrupts */ ksz_write32(dev, REG_SW_INT_MASK__4, SWITCH_INT_MASK);