2021-10-26 07:44:45

by Paul Menzel

[permalink] [raw]
Subject: Re: [Intel-wired-lan] [PATCH v2] e1000e: Add a delay to let ME unconfigure s0ix when DPG_EXIT_DONE is already flagged

Dear Kai-Heng,


On 26.10.21 08:51, Kai-Heng Feng wrote:

In the commit message summary, maybe write:

> e1000e: Add 1 s delay …


> On some ADL platforms, DPG_EXIT_DONE is always flagged so e1000e resume
> polling logic doesn't wait until ME really unconfigures s0ix.

Please list one broken system. The log message says, it’s a firmware
bug. Please elaborate.

> So check DPG_EXIT_DONE before issuing EXIT_DPG, and if it's already
> flagged, wait for 1 second to let ME unconfigure s0ix.

Where did you get the one second from?

> 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 <[email protected]>
> ---
> 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");

What firmware exactly? Management Engine?

> + msleep(1000);

One second is quite long. Can some bit be polled instead?

> + }
> +
> /* 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
>


Kind regards,

Paul