Re: [PATCH] lpfc: add PCI error recovery support

[James Smart <James.Smart@Emulex.Com>]

fyi - I'm not actually NACK'ing this, but letting everyone know
that Linas and I still working on the final bits. I will post upstream
when it is complete.

-- james s

Linas Vepstas wrote:
> James,
> 
> Please review the patch below. Presuming that you lke it,
> please forward upstream.
> 
> --linas
> 
> This patch adds PCI Error recovery support to the 
> Emulex Lightpulse Fibrechannel (lpfc) SCSI device driver.
> Lightly tested at this point, works.
> 
> Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
> Cc: James Smart <james.smart@emulex.com>
> 
> ----
> 
>  drivers/scsi/lpfc/lpfc_init.c |   91 ++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 91 insertions(+)
> 
> Index: linux-2.6.19-git7/drivers/scsi/lpfc/lpfc_init.c
> ===================================================================
> --- linux-2.6.19-git7.orig/drivers/scsi/lpfc/lpfc_init.c	2006-12-06 13:31:39.000000000 -0600
> +++ linux-2.6.19-git7/drivers/scsi/lpfc/lpfc_init.c	2006-12-06 13:33:49.000000000 -0600
> @@ -517,6 +517,11 @@ lpfc_handle_eratt(struct lpfc_hba * phba
>  	struct lpfc_sli_ring  *pring;
>  	uint32_t event_data;
>  
> +	/* If the pci channel is offline, ignore possible errors,
> +	 * since we cannot communicate with the pci card anyway. */
> +	if (pci_channel_offline(phba->pcidev))
> +		return;
> +
>  	if (phba->work_hs & HS_FFER6) {
>  		/* Re-establishing Link */
>  		lpfc_printf_log(phba, KERN_INFO, LOG_LINK_EVENT,
> @@ -1825,6 +1830,85 @@ lpfc_pci_remove_one(struct pci_dev *pdev
>  	pci_set_drvdata(pdev, NULL);
>  }
>  
> +/**
> + * lpfc_io_error_detected - called when PCI error is detected
> + * @pdev: Pointer to PCI device
> + * @state: The current pci conneection state
> + *
> + * This function is called after a PCI bus error affecting
> + * this device has been detected.
> + */
> +static pci_ers_result_t lpfc_io_error_detected(struct pci_dev *pdev, 
> +                        pci_channel_state_t state)
> +{
> +	if (state == pci_channel_io_perm_failure) {
> +		lpfc_pci_remove_one(pdev);
> +		return PCI_ERS_RESULT_DISCONNECT;
> +	}
> +	pci_disable_device(pdev);
> +
> +	/* Request a slot reset. */
> +	return PCI_ERS_RESULT_NEED_RESET;
> +}
> +
> +/**
> + * lpfc_io_slot_reset - called after the pci bus has been reset.
> + * @pdev: Pointer to PCI device
> + *
> + * Restart the card from scratch, as if from a cold-boot.
> + */
> +static pci_ers_result_t lpfc_io_slot_reset(struct pci_dev *pdev)
> +{
> +	struct Scsi_Host *host = pci_get_drvdata(pdev);
> +	struct lpfc_hba *phba = (struct lpfc_hba *)host->hostdata;
> +	struct lpfc_sli *psli = &phba->sli;
> +	struct lpfc_sli_ring  *pring;
> +
> +	dev_printk(KERN_INFO, &pdev->dev, "recovering from a slot reset.\n");
> +	if (pci_enable_device(pdev)) {
> +		printk(KERN_ERR "lpfc: Cannot re-enable PCI device after reset.\n");
> +		return PCI_ERS_RESULT_DISCONNECT;
> +	}
> +
> +	pci_set_master(pdev);
> +
> +	/* Re-establishing Link */
> +	spin_lock_irq(phba->host->host_lock);
> +	phba->fc_flag |= FC_ESTABLISH_LINK;
> +	psli->sli_flag &= ~LPFC_SLI2_ACTIVE;
> +	spin_unlock_irq(phba->host->host_lock);
> +
> +	/*
> +	 * There may be I/Os dropped by the firmware.
> +	 * Error iocb (I/O) on txcmplq and let the SCSI layer
> +	 * retry it after re-establishing link.
> +	 */
> +	pring = &psli->ring[psli->fcp_ring];
> +	lpfc_sli_abort_iocb_ring(phba, pring);
> +
> +	/* Take device offline; this will perform cleanup */
> +	lpfc_offline(phba);
> +	lpfc_sli_brdrestart(phba);
> +
> +	return PCI_ERS_RESULT_RECOVERED;
> +}
> +
> +/**
> + * lpfc_io_resume - called when traffic can start flowing again.
> + * @pdev: Pointer to PCI device
> + *
> + * This callback is called when the error recovery driver tells us that
> + * its OK to resume normal operation.
> + */
> +static void lpfc_io_resume(struct pci_dev *pdev)
> +{
> +	struct Scsi_Host *host = pci_get_drvdata(pdev);
> +	struct lpfc_hba *phba = (struct lpfc_hba *)host->hostdata;
> +
> +	lpfc_online(phba);
> +	mod_timer(&phba->fc_estabtmo, jiffies + HZ * 60);
> +}
> +
>  static struct pci_device_id lpfc_id_table[] = {
>  	{PCI_VENDOR_ID_EMULEX, PCI_DEVICE_ID_VIPER,
>  		PCI_ANY_ID, PCI_ANY_ID, },
> @@ -1885,11 +1969,18 @@ static struct pci_device_id lpfc_id_tabl
>  
>  MODULE_DEVICE_TABLE(pci, lpfc_id_table);
>  
> +static struct pci_error_handlers lpfc_err_handler = {
> +	.error_detected = lpfc_io_error_detected,
> +	.slot_reset = lpfc_io_slot_reset,
> +	.resume = lpfc_io_resume,
> +};
> +
>  static struct pci_driver lpfc_driver = {
>  	.name		= LPFC_DRIVER_NAME,
>  	.id_table	= lpfc_id_table,
>  	.probe		= lpfc_pci_probe_one,
>  	.remove		= __devexit_p(lpfc_pci_remove_one),
> +	.err_handler = &lpfc_err_handler,
>  };
>  
>  static int __init
>