From 848912e547c4569445a61203a7df402646a88c25 Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Thu, 12 May 2016 19:43:37 +1000 Subject: [PATCH] Revert "powerpc/powernv: Exclude root bus in pnv_pci_reset_secondary_bus()" This reverts commit c8ceacc22bce95d3a9cff198c9c27a30105a16b8. Gavin says: I missed the fact that it affects the PCI passthrou path as reported by Alexey: When passing GPU (0003:01:00.0) which seats behind the root port, the reset request is routed to skiboot in original code. In skiboot, the link bouncing events are masked during the reset. So we don't see EEH (freeze all) error even link bouncing happens. With the changes included, the reset is done by kernel and the link bouncing events aren't masked by altering content of PHB3 (or P7IOC) specific hardware registers which are invisible to kernel (skiboot hides the hardware specific). It means the link bouncing is seen by the root port and it causes a EEH (freeze all) error. The PCI passthrough on GPU device cannot work. Requested-by: Alexey Kardashevskiy Requested-by: Gavin Shan Signed-off-by: Michael Ellerman --- arch/powerpc/platforms/powernv/eeh-powernv.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c index 593b8dc0e137..9226df11bf39 100644 --- a/arch/powerpc/platforms/powernv/eeh-powernv.c +++ b/arch/powerpc/platforms/powernv/eeh-powernv.c @@ -868,8 +868,16 @@ static int pnv_eeh_bridge_reset(struct pci_dev *dev, int option) void pnv_pci_reset_secondary_bus(struct pci_dev *dev) { - pnv_eeh_bridge_reset(dev, EEH_RESET_HOT); - pnv_eeh_bridge_reset(dev, EEH_RESET_DEACTIVATE); + struct pci_controller *hose; + + if (pci_is_root_bus(dev->bus)) { + hose = pci_bus_to_host(dev->bus); + pnv_eeh_root_reset(hose, EEH_RESET_HOT); + pnv_eeh_root_reset(hose, EEH_RESET_DEACTIVATE); + } else { + pnv_eeh_bridge_reset(dev, EEH_RESET_HOT); + pnv_eeh_bridge_reset(dev, EEH_RESET_DEACTIVATE); + } } static void pnv_eeh_wait_for_pending(struct pci_dn *pdn, const char *type,