From: Daniel Axtens <dja@axtens•net>
To: Sam Bobroff <sam.bobroff@au1•ibm.com>, linuxppc-dev@lists•ozlabs.org
Subject: Re: [PATCH 1/9] powerpc/eeh: Remove eeh_handle_event()
Date: Tue, 06 Mar 2018 12:08:26 +1100 [thread overview]
Message-ID: <87tvtuc8ol.fsf@linkitivity.dja.id.au> (raw)
In-Reply-To: <d3d01073da02a5eb844cc8998fdac602b8121b62.1520294174.git.sam.bobroff@au1.ibm.com>
Hi Sam,
> The function eeh_handle_event(pe) does nothing other than switching
> between calling eeh_handle_normal_event(pe) and
> eeh_handle_special_event(). However it is only called in two places,
> one where pe can't be NULL and the other where it must be NULL (see
> eeh_event_handler()) so it does nothing but obscure the flow of
> control.
I've verified this.
>
> So, remove it.
Sounds good.
> + * While PHB detects address or data parity errors on particular PCI
> + * slot, the associated PE will be frozen. Besides, DMA's occurring
> + * to wild addresses (which usually happen due to bugs in device
> + * drivers or in PCI adapter firmware) can cause EEH error. #SERR,
> + * #PERR or other misc PCI-related errors also can trigger EEH errors.
> + *
> + * Recovery process consists of unplugging the device driver (which
> + * generated hotplug events to userspace), then issuing a PCI #RST to
> + * the device, then reconfiguring the PCI config space for all bridges
> + * & devices under this slot, and then finally restarting the device
> + * drivers (which cause a second set of hotplug events to go out to
> + * userspace).
> + *
So this is the comment from eeh_handle_event. This seems as good a place
as any to put it. (At some point someone should check if it lines up
well with Documentation/powerpc/eeh-pci-error-recovery.txt but it can wait.)
In conclusion:
Reviewed-by: Daniel Axtens <dja@axtens•net>
Thanks Sam!
Regards,
Daniel
> * Returns true if @pe should no longer be used, else false.
> */
> -static bool eeh_handle_normal_event(struct eeh_pe *pe)
> +bool eeh_handle_normal_event(struct eeh_pe *pe)
> {
> struct pci_bus *frozen_bus;
> struct eeh_dev *edev, *tmp;
> @@ -942,7 +955,7 @@ static bool eeh_handle_normal_event(struct eeh_pe *pe)
> * specific PE. Iterates through possible failures and handles them as
> * necessary.
> */
> -static void eeh_handle_special_event(void)
> +void eeh_handle_special_event(void)
> {
> struct eeh_pe *pe, *phb_pe;
> struct pci_bus *bus;
> @@ -1049,28 +1062,3 @@ static void eeh_handle_special_event(void)
> break;
> } while (rc != EEH_NEXT_ERR_NONE);
> }
> -
> -/**
> - * eeh_handle_event - Reset a PCI device after hard lockup.
> - * @pe: EEH PE
> - *
> - * While PHB detects address or data parity errors on particular PCI
> - * slot, the associated PE will be frozen. Besides, DMA's occurring
> - * to wild addresses (which usually happen due to bugs in device
> - * drivers or in PCI adapter firmware) can cause EEH error. #SERR,
> - * #PERR or other misc PCI-related errors also can trigger EEH errors.
> - *
> - * Recovery process consists of unplugging the device driver (which
> - * generated hotplug events to userspace), then issuing a PCI #RST to
> - * the device, then reconfiguring the PCI config space for all bridges
> - * & devices under this slot, and then finally restarting the device
> - * drivers (which cause a second set of hotplug events to go out to
> - * userspace).
> - */
> -void eeh_handle_event(struct eeh_pe *pe)
> -{
> - if (pe)
> - eeh_handle_normal_event(pe);
> - else
> - eeh_handle_special_event();
> -}
> diff --git a/arch/powerpc/kernel/eeh_event.c b/arch/powerpc/kernel/eeh_event.c
> index accbf8b5fd46..872bcfe8f90e 100644
> --- a/arch/powerpc/kernel/eeh_event.c
> +++ b/arch/powerpc/kernel/eeh_event.c
> @@ -81,10 +81,10 @@ static int eeh_event_handler(void * dummy)
> pr_info("EEH: Detected PCI bus error on "
> "PHB#%x-PE#%x\n",
> pe->phb->global_number, pe->addr);
> - eeh_handle_event(pe);
> + eeh_handle_normal_event(pe);
> eeh_pe_state_clear(pe, EEH_PE_RECOVERING);
> } else {
> - eeh_handle_event(NULL);
> + eeh_handle_special_event();
> }
>
> kfree(event);
> --
> 2.16.1.74.g9b0b1f47b
next prev parent reply other threads:[~2018-03-06 1:08 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-05 23:58 [PATCH 0/9] EEH refactoring 1 Sam Bobroff
2018-03-05 23:58 ` [PATCH 1/9] powerpc/eeh: Remove eeh_handle_event() Sam Bobroff
2018-03-06 0:44 ` Russell Currey
2018-03-06 1:08 ` Daniel Axtens [this message]
2018-03-05 23:58 ` [PATCH 2/9] powerpc/eeh: Manage EEH_PE_RECOVERING inside eeh_handle_normal_event() Sam Bobroff
2018-03-06 0:48 ` Russell Currey
2018-03-06 1:47 ` Daniel Axtens
2018-03-05 23:59 ` [PATCH 3/9] powerpc/eeh: Fix misleading comment in __eeh_addr_cache_get_device() Sam Bobroff
2018-03-06 0:49 ` Russell Currey
2018-03-05 23:59 ` [PATCH 4/9] powerpc/eeh: Remove misleading test in eeh_handle_normal_event() Sam Bobroff
2018-03-06 0:56 ` Russell Currey
2018-03-06 2:14 ` Daniel Axtens
2018-03-05 23:59 ` [PATCH 5/9] powerpc/eeh: Rename frozen_bus to bus " Sam Bobroff
2018-03-06 0:57 ` Russell Currey
2018-03-05 23:59 ` [PATCH 6/9] powerpc/eeh: Clarify arguments to eeh_reset_device() Sam Bobroff
2018-03-06 4:37 ` Russell Currey
2018-03-05 23:59 ` [PATCH 7/9] powerpc/eeh: Remove always-true tests in eeh_reset_device() Sam Bobroff
2018-03-06 4:38 ` Russell Currey
2018-03-05 23:59 ` [PATCH 8/9] powerpc/eeh: Factor out common code eeh_reset_device() Sam Bobroff
2018-03-06 5:48 ` Russell Currey
2018-03-06 0:00 ` [PATCH 9/9] powerpc/eeh: Add eeh_state_active() helper Sam Bobroff
2018-03-06 5:49 ` Russell Currey
2018-03-07 3:33 ` Sam Bobroff
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