Messages in this thread | | | Date | Tue, 2 Nov 2021 08:24:08 +0200 | Subject | Re: [PATCH v2] e1000e: Add a delay to let ME unconfigure s0ix when DPG_EXIT_DONE is already flagged | From | Sasha Neftin <> |
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On 11/2/2021 05:27, Kai-Heng Feng wrote: > On Fri, Oct 29, 2021 at 5:14 PM Sasha Neftin <sasha.neftin@intel.com> wrote: >> >> On 10/27/2021 01:50, Kai-Heng Feng wrote: >>> On Tue, Oct 26, 2021 at 4:48 PM Sasha Neftin <sasha.neftin@intel.com> wrote: >>>> >>>> On 10/26/2021 09:51, Kai-Heng Feng wrote: >>>>> On some ADL platforms, DPG_EXIT_DONE is always flagged so e1000e resume >>>>> polling logic doesn't wait until ME really unconfigures s0ix. >>>>> >>>>> So check DPG_EXIT_DONE before issuing EXIT_DPG, and if it's already >>>>> flagged, wait for 1 second to let ME unconfigure s0ix. >>>>> >>>>> Fixes: 3e55d231716e ("e1000e: Add handshake with the CSME to support S0ix") >>>>> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=214821 >>>>> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> >>>>> --- >>>>> v2: >>>>> Add missing "Fixes:" tag >>>>> >>>>> drivers/net/ethernet/intel/e1000e/netdev.c | 7 +++++++ >>>>> 1 file changed, 7 insertions(+) >>>>> >>>>> diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c >>>>> index 44e2dc8328a22..cd81ba00a6bc9 100644 >>>>> --- a/drivers/net/ethernet/intel/e1000e/netdev.c >>>>> +++ b/drivers/net/ethernet/intel/e1000e/netdev.c >>>>> @@ -6493,14 +6493,21 @@ static void e1000e_s0ix_exit_flow(struct e1000_adapter *adapter) >>>>> u32 mac_data; >>>>> u16 phy_data; >>>>> u32 i = 0; >>>>> + bool dpg_exit_done; >>>>> >>>>> if (er32(FWSM) & E1000_ICH_FWSM_FW_VALID) { >>>>> + dpg_exit_done = er32(EXFWSM) & E1000_EXFWSM_DPG_EXIT_DONE; >>>>> /* Request ME unconfigure the device from S0ix */ >>>>> mac_data = er32(H2ME); >>>>> mac_data &= ~E1000_H2ME_START_DPG; >>>>> mac_data |= E1000_H2ME_EXIT_DPG; >>>>> ew32(H2ME, mac_data); >>>>> >>>>> + if (dpg_exit_done) { >>>>> + e_warn("DPG_EXIT_DONE is already flagged. This is a firmware bug\n"); >>>>> + msleep(1000); >>>>> + } >>>> Thanks for working on the enablement. >>>> The delay approach is fragile. We need to work with CSME folks to >>>> understand why _DPG_EXIT_DONE indication is wrong on some ADL platforms. >>>> Could you provide CSME/BIOS version? dmidecode -t 0 and cat >>>> /sys/class/mei/mei0/fw_ver >>> >>> $ sudo dmidecode -t 0 >>> # dmidecode 3.2 >>> Getting SMBIOS data from sysfs. >>> SMBIOS 3.4 present. >>> # SMBIOS implementations newer than version 3.2.0 are not >>> # fully supported by this version of dmidecode. >>> >>> Handle 0x0001, DMI type 0, 26 bytes >>> BIOS Information >>> Vendor: Dell Inc. >>> Version: 0.12.68 >>> Release Date: 10/01/2021 >>> ROM Size: 48 MB >>> Characteristics: >>> PCI is supported >>> PNP is supported >>> BIOS is upgradeable >>> BIOS shadowing is allowed >>> Boot from CD is supported >>> Selectable boot is supported >>> EDD is supported >>> Print screen service is supported (int 5h) >>> 8042 keyboard services are supported (int 9h) >>> Serial services are supported (int 14h) >>> Printer services are supported (int 17h) >>> ACPI is supported >>> USB legacy is supported >>> BIOS boot specification is supported >>> Function key-initiated network boot is supported >>> Targeted content distribution is supported >>> UEFI is supported >>> BIOS Revision: 0.12 >>> >>> $ cat /sys/class/mei/mei0/fw_ver >>> 0:16.0.15.1518 >>> 0:16.0.15.1518 >>> 0:16.0.15.1518 >>> >> Thank you Kai-Heng. The _DPG_EXIT_DONE bit indication comes from the >> EXFWSM register controlled by the CSME. We have only read access. I >> realized that this indication was set to 1 even before our request to >> unconfigure the s0ix settings from the CSME. I am wondering. Does after >> a ~ 1s delay (or less, or more) _DPG_EXIT_DONE indication eventually >> change by CSME to 0? (is it consistently) > > Never. It's consistently being 1. no. On my TGL platform is cleared by CSME: [Sun Oct 31 08:54:40 2021] s0ix exit: EXFWSM register: 0x00000000 [Sun Oct 31 08:54:40 2021] s0ix exit (right after sent H2ME): EXFWSM register: 0x00000000 [Sun Oct 31 08:54:40 2021] s0ix exit(after polling): EXFWSM register: 0x00000001 [Sun Oct 31 08:54:40 2021] e1000e 0000:00:1f.6 enp0s31f6: DPG_EXIT_DONE cleared after 130 msec > > Right now we are seeing the same issue on TGL, so I wonder if it's > better to just revert the CSME series? no. We need to investigate it and understand what is CSME state we hit. Meanwhile few options: 1. use privilege flags to disable s0ix flow for problematic system (power will increased) ethtool --set-priv-flags enp0s31f6 s0ix-enabled off ethtool --show-priv-flags enp0s31f6 Private flags for enp0s31f6: s0ix-enabled: off 2. delay as you suggested - less preferable I though 3. I would like to suggest (need to check it) in case the DPG_EXIT_DONE is 1 (and polling will be exit immediately) - let's perform enforce settings to the CSME, before write request to CSME unconfigure the device from s0ix :
if (er32(EXFWSM) & E1000_EXFWSM_DPG_EXIT_DONE) mac_data |= E1000_H2ME_ENFORCE_SETTINGS;
I will update Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=214821 with this information.
I also will need some another information regards SMB state in this case. > > Kai-Heng > >>>>> /* Poll up to 2.5 seconds for ME to unconfigure DPG. >>>>> * If this takes more than 1 second, show a warning indicating a >>>>> * firmware bug >>>>> >>
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