[Skiboot] [PATCH 08/16] core/pci: Cache power state on slot without power control

[Gavin Shan]

For PCI slots depending on builtin power control functionality and
it's not supported, we should update (cache) the slot's power state
unconditionally. The slot's power state reflects the slot's hotplug
state (added or removed). Without this fix, the power and slot's
hotplug state are mismatched.

Signed-off-by: Gavin Shan <gwshan at linux.vnet.ibm.com>
---
 core/pcie-slot.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/core/pcie-slot.c b/core/pcie-slot.c
index 7fe3785..711e2e2 100644
--- a/core/pcie-slot.c
+++ b/core/pcie-slot.c
@@ -202,9 +202,13 @@ static int64_t pcie_slot_set_power_state(struct pci_slot *slot, uint8_t val)
 	if (slot->power_state == val)
 		return OPAL_PARAMETER;
 
-	/* Drop the request if functionality doesn't exist */
-	if (!(slot->slot_cap & PCICAP_EXP_SLOTCAP_PWCTRL))
+	/* Update the power state and return immediately if the power
+	 * control functionality isn't supported on the PCI slot.
+	 */
+	if (!(slot->slot_cap & PCICAP_EXP_SLOTCAP_PWCTRL)) {
+		slot->power_state = val;
 		return OPAL_SUCCESS;
+	}
 
 	pci_slot_set_state(slot, PCI_SLOT_STATE_SPOWER_START);
 	slot->power_state = val;
-- 
2.1.0