On Fri, Oct 23, 2015 at 05:19:46PM +1100, Andrew Donnellan wrote:
>In eeh_pci_enable(), after making the request to set the new options, we
>call eeh_ops->wait_state() to check that the request finished successfully.
>
>At the moment, if eeh_ops->wait_state() returns 0, we return 0 without
>checking that it reflects the expected outcome. This can lead to callers
>further up the chain incorrectly assuming the slot has been successfully
>unfrozen and continuing to attempt recovery.
>
>On powernv, this will occur if pnv_eeh_get_pe_state() or
>pnv_eeh_get_phb_state() return 0, which in turn occurs if the relevant OPAL
>call returns OPAL_EEH_STOPPED_MMIO_DMA_FREEZE or
>OPAL_EEH_PHB_ERROR respectively.
>
>On pseries, this will occur if pseries_eeh_get_state() returns 0, which in
>turn occurs if RTAS reports that the PE is in the MMIO Stopped and DMA
>Stopped states.
>
>Obviously, none of these cases represent a successful completion of a
>request to thaw MMIO or DMA.
>
>Fix the check so that a wait_state() return value of 0 won't be considered
>successful for the EEH_OPT_THAW_MMIO or EEH_OPT_THAW_DMA cases.
>
>Cc: Gavin Shan <gws...@linux.vnet.ibm.com>
>Signed-off-by: Andrew Donnellan <andrew.donnel...@au1.ibm.com>
Acked-by: Gavin Shan <gws...@linux.vnet.ibm.com>
Thanks,
Gavin
>---
> arch/powerpc/kernel/eeh.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
>diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
>index 40e4d4a..d757e7c 100644
>--- a/arch/powerpc/kernel/eeh.c
>+++ b/arch/powerpc/kernel/eeh.c
>@@ -677,7 +677,7 @@ int eeh_pci_enable(struct eeh_pe *pe, int function)
> /* Check if the request is finished successfully */
> if (active_flag) {
> rc = eeh_ops->wait_state(pe, PCI_BUS_RESET_WAIT_MSEC);
>- if (rc <= 0)
>+ if (rc < 0)
> return rc;
>
> if (rc & active_flag)
>--
>Andrew Donnellan Software Engineer, OzLabs
>andrew.donnel...@au1.ibm.com Australia Development Lab, Canberra
>+61 2 6201 8874 (work) IBM Australia Limited
>
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