Re: [PATCH net] net: dsa: microchip: fix initial port flush problem
From: Simon Horman <horms@kernel.org>
Date: 2024-05-31 19:02:39
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On Tue, May 28, 2024 at 02:35:45PM -0700, Tristram.Ha@microchip.com wrote:
From: Tristram Ha <redacted> The very first flush in any port will flush all learned addresses in all ports. This can be observed by unplugging a 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 register. After the first flush the value is reset back to the normal so the next port flush will not cause such problem again.
Hi Tristram, I think it would be worth spelling out why it is correct to: 1. Not set SW_FLUSH_STP_TABLE or SW_FLUSH_MSTP_TABLE; and 2. Preserve the value of the other bits of REG_SW_LUE_CTRL_1
quoted hunk ↗ jump to hunk
Fixes: b987e98e50ab ("dsa: add DSA switch driver for Microchip KSZ9477") Signed-off-by: Tristram Ha <redacted> --- drivers/net/dsa/microchip/ksz9477.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)diff --git a/drivers/net/dsa/microchip/ksz9477.c b/drivers/net/dsa/microchip/ksz9477.c index f8ad7833f5d9..7cc92b90ffea 100644 --- a/drivers/net/dsa/microchip/ksz9477.c +++ b/drivers/net/dsa/microchip/ksz9477.c@@ -356,8 +356,7 @@ int ksz9477_reset_switch(struct ksz_device *dev) /* 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; + data8 |= SW_AGING_ENABLE | SW_LINK_AUTO_AGING | SW_SRC_ADDR_FILTER; ksz_write8(dev, REG_SW_LUE_CTRL_1, data8); /* disable interrupts */-- 2.34.1