Subject: [PATCH] powerpc/powernv: Escalate reset when IODA reset fails

From: Oliver O'Halloran <[email-masked]>
Date: Fri, 1 Feb 2019 11:42:01 +1100

The IODA reset is used to flush out any OS controlled state from the PHB.
This reset can fail if a PHB fatal error has occurred in early boot,
probably due to a because of a bad device. We already do a fundemental
reset of the device in some cases, so this patch just adds a test to force
a full reset if firmware reports an error when performing the IODA reset.

Signed-off-by: Oliver O'Halloran <[email-masked]>
---
 arch/powerpc/platforms/powernv/pci-ioda.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 1d6406a..53982f8 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -3943,9 +3943,12 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
 	 * shutdown PCI devices correctly. We already got IODA table
 	 * cleaned out. So we have to issue PHB reset to stop all PCI
 	 * transactions from previous kernel. The ppc_pci_reset_phbs
-	 * kernel parameter will force this reset too.
+	 * kernel parameter will force this reset too. Additionally,
+	 * if the IODA reset above failed then use a bigger hammer.
+	 * This can happen if we get a PHB fatal error in very early
+	 * boot.
 	 */
-	if (is_kdump_kernel() || pci_reset_phbs) {
+	if (is_kdump_kernel() || pci_reset_phbs || rc) {
 		pr_info("  Issue PHB reset ...\n");
 		pnv_eeh_phb_reset(hose, EEH_RESET_FUNDAMENTAL);
 		pnv_eeh_phb_reset(hose, EEH_RESET_DEACTIVATE);
-- 
2.9.4