[Intel-wired-lan] [PATCH v2] e1000e: move force SMBUS near the end of enable_ulp function
Paul Menzel
pmenzel at molgen.mpg.de
Fri May 17 10:07:36 UTC 2024
Dear Hui,
Thank you for your response.
Am 17.05.24 um 11:45 schrieb Hui Wang:
>
> On 5/17/24 13:45, Paul Menzel wrote:
>> Am 08.05.24 um 14:06 schrieb Hui Wang:
>>> The commit 861e8086029e ("e1000e: move force SMBUS from enable ulp
>>> function to avoid PHY loss issue") introduces a regression on
>>> CH_MTP_I219_LM18 (PCIID: 0x8086550A). Without the referred commit, the
>>
>> *P*CH
>>
>>> ethernet works well after suspend and resume, but after applying the
>>> commit, the ethernet couldn't work anymore after the resume and the
>>> dmesg shows that the NIC Link changes to 10Mbps (1000Mbps originally):
>>
>> 1. s/Link/link/
>> 2. “couldn’t work” means the reduced bandwidth?
>
> On my side, once the link changes to 10Mbps, I couldn't ping the machine
> anymore. And as you said, it probably has sth to do with switch/router
> configuration.
>
>> 3. Please add a blank line and maybe indent the past with four spaces.
>>
>>> [ 43.305084] e1000e 0000:00:1f.6 enp0s31f6: NIC Link is Up 10 Mbps Full Duplex, Flow Control: Rx/Tx
>>>
>>> Without the commit, the force SMBUS code will not be executed if
>>> "return 0" or "goto out" is executed in the enable_ulp(), and in my
>>> case, the "goto out" is executed since FWSM_FW_VALID is set. But after
>>> applying the commit, the force SMBUS code will be ran unconditionally.
>>>
>>> Here move the force SMBUS code back to enable_ulp() and put it
>>> immediate ahead of hw->phy.ops.release(hw), this could allow the
>>
>> immediate*l*?
Sorry, I meant immediate*ly*.
>>> longest settling time as possible for interface in this function and
>>> doesn't change the original code logic.
>>
>> Re-ordering code to achieve some waiting time sounds like, it’s not
>> 100 % sure, that the problem won’t occur again?
>
> Actually this patch not only adds the waiting time, but also restore the
> original code logic:
>
> original: On a machine with the CSME, the SMBUS will not be forced,
> accordingly the SMBUS will not be unforced after resume.
>
> wrong: On a machine with the CSME, the SMBUS is forced, but the SMBUS
> is not unforced after resume, there is an unbalance. My patch could fix
> this case.
Thank you for elaborating. In my opinion, then two commits would be
better. One revert with a description of the problem and documentation
of the test systems. Then the second patch with the fix.
>> Could you please document your test system?
> Lenovo Thinkpad P16Gen2 with ethernet card:
>
> 00:1f.6 Ethernet controller [0200]: Intel Corporation Device [8086:550a] (rev 20)
>
>> Just a side note: Booting Linux 6.9-rc5+ *with kexec* on Supermicro
>> Super Server/X13SAE, BIOS 2.0 10/17/2022 with the network device
>> below, it also came up only with 10 Mbps and Ethernet did not work,
>> for example `ping`. I conjectured though, that the non-working part
>> was due to the switch configuration not allowing 10 Mbps.
>>
>> 00:1f.6 Ethernet controller [0200]: Intel Corporation Ethernet Connection (17) I219-LM [8086:1a1c] (rev 11)
>>
> My test and result are same as yours.
>
> Thanks.
Thank you for the confirmation.
>> I didn’t find the time to further analyze and report the issue.
>>
>> Also could this also be related to the regression reported by the
>> kernel test robot [1]?
>>
>> 00:19.0 Ethernet controller: Intel Corporation Ethernet Connection (3) I218-V (rev 03)
>>
>>> Fixes: 861e8086029e ("e1000e: move force SMBUS from enable ulp
>>> function to avoid PHY loss issue")
>>> Signed-off-by: Hui Wang <hui.wang at canonical.com>
>>> Acked-by: Vitaly Lifshits <vitaly.lifshits at intel.com>
>>> Tested-by: Naama Meir <naamax.meir at linux.intel.com>
>>> Signed-off-by: Tony Nguyen <anthony.l.nguyen at intel.com>
>>> ---
>>> In the v2:
>>> Change "this commit" to "the referred commit" in the commit header
>>> Fix a potential infinite loop if ret_val is not zero
>>> drivers/net/ethernet/intel/e1000e/ich8lan.c | 22 +++++++++++++++++++++
>>> drivers/net/ethernet/intel/e1000e/netdev.c | 18 -----------------
>>> 2 files changed, 22 insertions(+), 18 deletions(-)
>>>
>>> diff --git a/drivers/net/ethernet/intel/e1000e/ich8lan.c
>>> b/drivers/net/ethernet/intel/e1000e/ich8lan.c
>>> index f9e94be36e97..2e98a2a0bead 100644
>>> --- a/drivers/net/ethernet/intel/e1000e/ich8lan.c
>>> +++ b/drivers/net/ethernet/intel/e1000e/ich8lan.c
>>> @@ -1225,6 +1225,28 @@ s32 e1000_enable_ulp_lpt_lp(struct e1000_hw
>>> *hw, bool to_sx)
>>> }
>>> release:
>>> + /* Switching PHY interface always returns MDI error
>>> + * so disable retry mechanism to avoid wasting time
>>> + */
>>> + e1000e_disable_phy_retry(hw);
>>> +
>>> + /* Force SMBus mode in PHY */
>>> + ret_val = e1000_read_phy_reg_hv_locked(hw, CV_SMB_CTRL, &phy_reg);
>>> + if (ret_val) {
>>> + e1000e_enable_phy_retry(hw);
>>> + hw->phy.ops.release(hw);
>>> + goto out;
>>> + }
>>> + phy_reg |= CV_SMB_CTRL_FORCE_SMBUS;
>>> + e1000_write_phy_reg_hv_locked(hw, CV_SMB_CTRL, phy_reg);
>>> +
>>> + e1000e_enable_phy_retry(hw);
>>> +
>>> + /* Force SMBus mode in MAC */
>>> + mac_reg = er32(CTRL_EXT);
>>> + mac_reg |= E1000_CTRL_EXT_FORCE_SMBUS;
>>> + ew32(CTRL_EXT, mac_reg);
>>> +
>>> hw->phy.ops.release(hw);
>>> out:
>>> if (ret_val)
>>> diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c
>>> b/drivers/net/ethernet/intel/e1000e/netdev.c
>>> index 3692fce20195..cc8c531ec3df 100644
>>> --- a/drivers/net/ethernet/intel/e1000e/netdev.c
>>> +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
>>> @@ -6623,7 +6623,6 @@ static int __e1000_shutdown(struct pci_dev
>>> *pdev, bool runtime)
>>> struct e1000_hw *hw = &adapter->hw;
>>> u32 ctrl, ctrl_ext, rctl, status, wufc;
>>> int retval = 0;
>>> - u16 smb_ctrl;
>>> /* Runtime suspend should only enable wakeup for link changes */
>>> if (runtime)
>>> @@ -6697,23 +6696,6 @@ static int __e1000_shutdown(struct pci_dev
>>> *pdev, bool runtime)
>>> if (retval)
>>> return retval;
>>> }
>>> -
>>> - /* Force SMBUS to allow WOL */
>>> - /* Switching PHY interface always returns MDI error
>>> - * so disable retry mechanism to avoid wasting time
>>> - */
>>> - e1000e_disable_phy_retry(hw);
>>> -
>>> - e1e_rphy(hw, CV_SMB_CTRL, &smb_ctrl);
>>> - smb_ctrl |= CV_SMB_CTRL_FORCE_SMBUS;
>>> - e1e_wphy(hw, CV_SMB_CTRL, smb_ctrl);
>>> -
>>> - e1000e_enable_phy_retry(hw);
>>> -
>>> - /* Force SMBus mode in MAC */
>>> - ctrl_ext = er32(CTRL_EXT);
>>> - ctrl_ext |= E1000_CTRL_EXT_FORCE_SMBUS;
>>> - ew32(CTRL_EXT, ctrl_ext);
>>> }
>>> /* Ensure that the appropriate bits are set in LPI_CTRL
Kind regards,
Paul
>> [1]: https://lore.kernel.org/intel-wired-lan/202405150942.f9b873b1-oliver.sang@intel.com/
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