Re: [Intel-wired-lan] [PATCH v4] e1000e: Increase polling timeout on MDIC ready bit

Neftin, Sasha
2020-09-29T13:08:57Z

On 9/28/2020 11:36, Kai-Heng Feng wrote:
> We are seeing the following error after S3 resume:
> [ 704.746874] e1000e 0000:00:1f.6 eno1: Setting page 0x6020
> [ 704.844232] e1000e 0000:00:1f.6 eno1: MDI Write did not complete
> [ 704.902817] e1000e 0000:00:1f.6 eno1: Setting page 0x6020
> [ 704.903075] e1000e 0000:00:1f.6 eno1: reading PHY page 769 (or 0x6020 shifted) reg 0x17
> [ 704.903281] e1000e 0000:00:1f.6 eno1: Setting page 0x6020
> [ 704.903486] e1000e 0000:00:1f.6 eno1: writing PHY page 769 (or 0x6020 shifted) reg 0x17
> [ 704.943155] e1000e 0000:00:1f.6 eno1: MDI Error
> ...
> [ 705.108161] e1000e 0000:00:1f.6 eno1: Hardware Error
>
> As Andrew Lunn pointed out, MDIO has nothing to do with phy, and indeed
> increase polling iteration can resolve the issue.
>
> This patch only papers over the symptom, as we don't really know the
> root cause of the issue. The most possible culprit is Intel ME, which
> may do its own things that conflict with software.
>
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> ---
> v4:
> - States that this patch just papers over the symptom.
>
> v3:
> - Moving delay to end of loop doesn't save anytime, move it back.
> - Point out this is quitely likely caused by Intel ME.
>
> v2:
> - Increase polling iteration instead of powering down the phy.
>
> drivers/net/ethernet/intel/e1000e/phy.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/intel/e1000e/phy.c b/drivers/net/ethernet/intel/e1000e/phy.c
> index e11c877595fb..e6d4acd90937 100644
> --- a/drivers/net/ethernet/intel/e1000e/phy.c
> +++ b/drivers/net/ethernet/intel/e1000e/phy.c
> @@ -203,7 +203,7 @@ s32 e1000e_write_phy_reg_mdic(struct e1000_hw *hw, u32 offset, u16 data)
> * Increasing the time out as testing showed failures with
> * the lower time out
> */
> - for (i = 0; i < (E1000_GEN_POLL_TIMEOUT * 3); i++) {
> + for (i = 0; i < (E1000_GEN_POLL_TIMEOUT * 10); i++) {
As we discussed (many threads) - AMT/ME systems not supported on Linux
as properly. I do not think increasing polling iteration will solve the
problem. Rather mask it.
I prefer you check option to disable ME vi BIOS on your system.
> udelay(50);
> mdic = er32(MDIC);
> if (mdic & E1000_MDIC_READY)
>
Thanks,
Sasha