Re: [PATCH v2 02/15] lpfc: Fix auto sli_mode and its effect on CONFIG_PORT for SLI3

[Daniel Wagner <dwagner@suse.de>]

Hi James,

On Mon, Jan 04, 2021 at 10:02:27AM -0800, James Smart wrote:
> A very long time ago, there was a feature: auto sli mode. It gave the
> user the ability to auto select the SLI mode (SLI2 or SLI3) to run the
> port in, or even force SLI2 mode if configured.  Because of the
> convoluted logic, the CONFIG_PORT mbox command ends up being called 2 or
> 3 times. It should have been called only once.  Additionally, the driver
> no longer supports SLI-2, so only SLI-3 mode should be allowed.
> 
> The following changes were made:
> - Force module parameter to SLI3 only.
> - Rip out redundant CONFIG_PORT mbox commands.
> - Force CONFIG_PORT mbox command to be in beginning of enable ISR routine.
> - Added changes for offline to online behavior

We got a regression report for this patch. The problem seems to be
related with older Emulex HBAs. The symptom is in this case one port is
not enabled. A revert of this patch fixed the problem. This was
observed with:

  Emulex LPe11000 FV2.72X2 DV12.8.0.7 HN:FR2AS6AP2-0001 OS:Linux

Here some ramblings from my debugging:

In the logs I found:

> 0000:0b:00.0: 0:0431 Failed to enable interrupt.
> 0000:0b:00.0: 0:0431 Failed to enable interrupt.
> 0000:0b:00.0: 0:0431 Failed to enable interrupt.

cfg_sli_mode used to be 0 (auto) and the config port setup
used to try first mode = 3 and then fall back to mode = 2

> -       rc = lpfc_sli_config_port(phba, mode);
> -
> -       if (rc && phba->cfg_sli_mode == 3)
> -               lpfc_printf_log(phba, KERN_ERR, LOG_TRACE_EVENT,
> -                               "1820 Unable to select SLI-3.  "
> -                               "Not supported by adapter.\n");
> -       if (rc && mode != 2)
> -               rc = lpfc_sli_config_port(phba, 2);

the port config is now in lpfc_sli_enable_intr which is hardcoded
to LPFC_SLI_REV3 and I think this fails and the HBA_NEEDS_CFG_PORT
flag is not resetted, hence in lpfc_sli_hba_setup() the new
code tries to enable the port again with:

> +       /* Enable ISR already does config_port because of config_msi mbx */
> +       if (phba->hba_flag & HBA_NEEDS_CFG_PORT) {
> +               rc = lpfc_sli_config_port(phba, LPFC_SLI_REV3);
> +               if (rc)
> +                       return -EIO;
> +               phba->hba_flag &= ~HBA_NEEDS_CFG_PORT;

Though I think this should something like

   lpfc_sli_config_port(phba, LPFC_SLI_REV2);

for the specific case.

HTH!

Thanks,
Daniel