[PATCH net-next v2] net: dsa: motorcomm: Remove the redundant MIB clear

[PATCH net-next v2] net: dsa: motorcomm: Remove the redundant MIB clear

[David Yang]

The MIB clear in yt921x_chip_setup() is redundant. yt921x_dsa_setup()
issues a hardware reset first, and the reset itself zeroes all the MIB
counters.

It does not follow the correct procedure either: CLEAN only takes effect
while ALL_PORT is low, so a single-step CLEAN | ALL_PORT write does
nothing once ALL_PORT is latched - and this write is what latches it for
any CLEAN requested later.

Signed-off-by: David Yang <mmyangfl@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
v2:
  - reword
v1: https://lore.kernel.org/r/20261010231015.2600207-1-mmyangfl@gmail.com
 drivers/net/dsa/motorcomm/chip.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/net/dsa/motorcomm/chip.c b/drivers/net/dsa/motorcomm/chip.c
index 91cc5647f2b6..5218beb77ec7 100644
--- a/drivers/net/dsa/motorcomm/chip.c
+++ b/drivers/net/dsa/motorcomm/chip.c
@@ -3902,12 +3902,6 @@ static int yt921x_chip_setup(struct yt921x_priv *priv)
 		return res;
 #endif
 
-	/* Clear MIB */
-	ctrl = YT921X_MIB_CTRL_CLEAN | YT921X_MIB_CTRL_ALL_PORT;
-	res = yt921x_reg_write(priv, YT921X_MIB_CTRL, ctrl);
-	if (res)
-		return res;
-
 	/* Miscellaneous */
 	res = yt921x_reg_set_bits(priv, YT921X_SENSOR, YT921X_SENSOR_TEMP);
 	if (res)
-- 
2.53.0

Re: [PATCH net-next v2] net: dsa: motorcomm: Remove the redundant MIB clear

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (main)
by Paolo Abeni <pabeni@redhat.com>:

On Thu, 15 Oct 2026 08:44:19 +0800 you wrote:
> The MIB clear in yt921x_chip_setup() is redundant. yt921x_dsa_setup()
> issues a hardware reset first, and the reset itself zeroes all the MIB
> counters.
> 
> It does not follow the correct procedure either: CLEAN only takes effect
> while ALL_PORT is low, so a single-step CLEAN | ALL_PORT write does
> nothing once ALL_PORT is latched - and this write is what latches it for
> any CLEAN requested later.
> 
> [...]

Here is the summary with links:
  - [net-next,v2] net: dsa: motorcomm: Remove the redundant MIB clear
    https://git.kernel.org/netdev/net-next/c/7d23f0f650d9

You are awesome, thank you!
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