On Fri, Apr 22, 2016 at 11:28:02PM +1000, Gavin Shan wrote: > The function eeh_pe_reset_and_recover() is used to recover EEH > error when the passthrough device are transferred to guest and > backwards, meaning the device's driver is vfio-pci or none. > When the driver is vfio-pci that provides error_detected() error > handler only, the handler simply stops the guest and it's not > expected behaviour. On the other hand, no error handlers will > be called if we don't have a bound driver. > > This ignores all error handlers provided by device driver in > eeh_pe_reset_and_recover() to avoid the exceptional behaviour. > > Fixes: 5cfb20b9 ("powerpc/eeh: Emulate EEH recovery for VFIO devices") > Cc: sta...@vger.kernel.org #v3.18+ > Signed-off-by: Gavin Shan <gws...@linux.vnet.ibm.com> > Reviewed-by: Russell Currey <rus...@russell.cc> > --- > arch/powerpc/kernel/eeh_driver.c | 11 +---------- > 1 file changed, 1 insertion(+), 10 deletions(-) > > diff --git a/arch/powerpc/kernel/eeh_driver.c > b/arch/powerpc/kernel/eeh_driver.c > index fb6207d..1c7d703 100644 > --- a/arch/powerpc/kernel/eeh_driver.c > +++ b/arch/powerpc/kernel/eeh_driver.c > @@ -552,7 +552,7 @@ static int eeh_clear_pe_frozen_state(struct eeh_pe *pe, > > int eeh_pe_reset_and_recover(struct eeh_pe *pe) > { > - int result, ret; > + int ret; > > /* Bail if the PE is being recovered */ > if (pe->state & EEH_PE_RECOVERING) > @@ -564,9 +564,6 @@ int eeh_pe_reset_and_recover(struct eeh_pe *pe) > /* Save states */ > eeh_pe_dev_traverse(pe, eeh_dev_save_state, NULL); > > - /* Report error */ > - eeh_pe_dev_traverse(pe, eeh_report_error, &result);
Ok, so after chatting to Gavin, I've made sense of this. The basic thing here is that eeh_pe_reset_and_recover() should be discarding any errors from before the reset, not reporting them - the whole point is that we know things have gone bad, and we want to clear back to a good state. > /* Issue reset */ > ret = eeh_reset_pe(pe); > if (ret) { > @@ -581,15 +578,9 @@ int eeh_pe_reset_and_recover(struct eeh_pe *pe) > return ret; > } > > - /* Notify completion of reset */ > - eeh_pe_dev_traverse(pe, eeh_report_reset, &result); However, it's not clear if removing the report of a reset makes sense. There are no current users of reset notification IIUC, but if we're going to remove the reset reporting, we should put that in a separate patch with its own justification, and remove the other caller as well. > /* Restore device state */ > eeh_pe_dev_traverse(pe, eeh_dev_restore_state, NULL); > > - /* Resume */ > - eeh_pe_dev_traverse(pe, eeh_report_resume, NULL); And I'm not sure if it makes sense to remove the resume notification either. > /* Clear recovery mode */ > eeh_pe_state_clear(pe, EEH_PE_RECOVERING); > -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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