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

[Vitaly Lifshits]

On 9/29/2020 18:08, Kai-Heng Feng wrote:

Hello Kai-Heng,
> > On Sep 29, 2020, at 21:46, Neftin, Sasha <sasha.neftin@xxxxxxxxx> wrote:
> >
> > Hello Kai-Heng,
> > On 9/29/2020 16:31, Kai-Heng Feng wrote:
> > > Hi Sasha,
> > > > On Sep 29, 2020, at 21:08, Neftin, Sasha <sasha.neftin@xxxxxxxxx> wrote:
> > > >
> > > > 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@xxxxxxxxxxxxx>
> > > > > ---
> > > > > 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 am aware of the status quo of no proper support on Intel ME.
> > > > I prefer you check option to disable ME vi BIOS on your system.
> > > We can't ask user to change the BIOS to accommodate Linux. So before a proper solution comes out, masking the problem is good enough for me.
> > > Until then, I'll carry it as a downstream distro patch.
> > What will you do with system that even after increasing polling time will run into HW error?
>
> Hope we finally have proper ME support under Linux?
>
> Kai-Heng
>
> > > Kai-Heng
> > > > >   		udelay(50);
> > > > >   		mdic = er32(MDIC);
> > > > >   		if (mdic & E1000_MDIC_READY)
> > > > Thanks,
> > > > Sasha
> > Thanks,
> > Sasha

On which device ID/platform do you see the issue? What is the Firmware 
version on your platform? What is the ME firmware version that you have?

I am asking these questions, since I know there is supposed to be a fix 
in the firmware to many issues that are related to ME and device 
interoperability.

Thanks,

Vitaly