[PATCH net 1/1] igb: skip phy status check where unavailable

[PATCH net 1/1] igb: skip phy status check where unavailable

[Tony Nguyen]

From: Kevin Mitchell <kevmitch@arista.com>

igb_read_phy_reg() will silently return, leaving phy_data untouched, if
hw->ops.read_reg isn't set. Depending on the uninitialized value of
phy_data, this led to the phy status check either succeeding immediately
or looping continuously for 2 seconds before emitting a noisy err-level
timeout. This message went out to the console even though there was no
actual problem.

Instead, first check if there is read_reg function pointer. If not,
proceed without trying to check the phy status register.

Fixes: b72f3f72005d ("igb: When GbE link up, wait for Remote receiver status condition")
Signed-off-by: Kevin Mitchell <kevmitch@arista.com>
Tested-by: Gurucharan <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/igb/igb_main.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index 34b33b21e0dc..68be2976f539 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -5505,7 +5505,8 @@ static void igb_watchdog_task(struct work_struct *work)
 				break;
 			}
 
-			if (adapter->link_speed != SPEED_1000)
+			if (adapter->link_speed != SPEED_1000 ||
+			    !hw->phy.ops.read_reg)
 				goto no_wait;
 
 			/* wait for Remote receiver status OK */
-- 
2.35.1

Re: [PATCH net 1/1] igb: skip phy status check where unavailable

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (master)
by David S. Miller <davem@davemloft.net>:

On Tue, 17 May 2022 11:01:05 -0700 you wrote:
> From: Kevin Mitchell <kevmitch@arista.com>
> 
> igb_read_phy_reg() will silently return, leaving phy_data untouched, if
> hw->ops.read_reg isn't set. Depending on the uninitialized value of
> phy_data, this led to the phy status check either succeeding immediately
> or looping continuously for 2 seconds before emitting a noisy err-level
> timeout. This message went out to the console even though there was no
> actual problem.
> 
> [...]

Here is the summary with links:
  - [net,1/1] igb: skip phy status check where unavailable
    https://git.kernel.org/netdev/net/c/942d2ad5d2e0

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html