[PATCH 2/3] drivers/pci/hotplug: Fix initial state for empty slot

From
Gavin Shan <hidden>
Date
2017-01-11 00:50:19
Also in
stable
Reply to
Gavin Shan, 2017-01-11
In PowerNV PCI hotplug driver, the initial PCI slot's state is set
to PNV_PHP_STATE_POPULATED if no PCI devices are connected to the
slot. The PCI devices that are hot added to the slot won't be probed
and populated because of the check in pnv_php_enable():

        /* Check if the slot has been configured */
        if (php_slot->state != PNV_PHP_STATE_REGISTERED)
                return 0;

This fixes the issue by leaving the slot in PNV_PHP_STATE_REGISTERED
state initially if nothing is connected to the slot.

Fixes: 360aebd85a4 ("drivers/pci/hotplug: Support surprise hotplug in powernv driver")
Cc: <redacted> #v4.9+
Reported-by: Hank Chang <redacted>
Signed-off-by: Gavin Shan <redacted>
Tested-by: Willie Liauw <redacted>
---
 drivers/pci/hotplug/pnv_php.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c
index 306728c..41304b3 100644
--- a/drivers/pci/hotplug/pnv_php.c
+++ b/drivers/pci/hotplug/pnv_php.c
@@ -430,9 +430,21 @@ static int pnv_php_enable(struct pnv_php_slot *php_slot, bool rescan)
 	if (ret)
 		return ret;
 
-	/* Proceed if there have nothing behind the slot */
-	if (presence == OPAL_PCI_SLOT_EMPTY)
+	/*
+	 * Proceed if there have nothing behind the slot. However,
+	 * we should leave the slot in registered state at the
+	 * beginning. Otherwise, the PCI devices inserted afterwards
+	 * won't be probed and populated.
+	 */
+	if (presence == OPAL_PCI_SLOT_EMPTY) {
+		if (!php_slot->power_state_check) {
+			php_slot->power_state_check = true;
+
+			return 0;
+		}
+
 		goto scan;
+	}
 
 	/*
 	 * If the power supply to the slot is off, we can't detect
-- 
2.7.4
Thread (6 messages) 6 messages, 2 authors, last reply 2017-02-16
Keyboard shortcuts
hback out one level
jnext message in thread / next series-diff position
kprevious message in thread / previous series-diff position
ldrill in
Escclose help / fold thread tree
?toggle this help