diff mbox series

[v1,net] net: dsa: microchip: fix initial port flush problem

Message ID 1718756202-2731-1-git-send-email-Tristram.Ha@microchip.com (mailing list archive)
State Accepted
Commit ad53f5f54f351e967128edbc431f0f26427172cf
Delegated to: Netdev Maintainers
Headers show
Series [v1,net] net: dsa: microchip: fix initial port flush problem | expand

Checks

Context Check Description
netdev/series_format success Single patches do not need cover letters
netdev/tree_selection success Clearly marked for net
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 859 this patch: 859
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 9 of 9 maintainers
netdev/build_clang success Errors and warnings before: 863 this patch: 863
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 863 this patch: 863
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 12 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-06-20--03-00 (tests: 659)

Commit Message

Tristram.Ha@microchip.com June 19, 2024, 12:16 a.m. UTC 
From: Tristram Ha <tristram.ha@microchip.com>

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 <tristram.ha@microchip.com>
---
v1
 - explain how the 2 extra bits affect the flushing operation
 - write directly to disable the default SW_FWD_MCAST_SRC_ADDR bit and so
   no need to read the register first

 drivers/net/dsa/microchip/ksz9477.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

Comments

patchwork-bot+netdevbpf@kernel.org June 21, 2024, 2:40 a.m. UTC | #1 
Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Tue, 18 Jun 2024 17:16:42 -0700 you wrote:
> From: Tristram Ha <tristram.ha@microchip.com>
> 
> 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.
> 
> [...]

Here is the summary with links:
  - [v1,net] net: dsa: microchip: fix initial port flush problem
    https://git.kernel.org/netdev/net/c/ad53f5f54f35

You are awesome, thank you!
diff mbox series

Patch

diff --git a/drivers/net/dsa/microchip/ksz9477.c b/drivers/net/dsa/microchip/ksz9477.c
index f8ad7833f5d9..2231128eef8b 100644
--- a/drivers/net/dsa/microchip/ksz9477.c
+++ b/drivers/net/dsa/microchip/ksz9477.c
@@ -355,10 +355,8 @@  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);