On failure pcie_capability_read_word() sets it's last parameter, val
to 0. However, with Patch 12/12, it is possible that val is set to
~0 on failure. This introduces a bug because (x & x) == (~0 & x).
Since ~0 is an invalid value here,
pciehp_get_power_status():
Add an extra check for ~0 on the value read. If found, set status
to 'Power On' and return.
pcie_wait_for_presence():
Add an extra check for no ~0 to the exit condition of the loop
Suggested-by: Bjorn Helgaas <bjorn@xxxxxxxxxxx>
Signed-off-by: Saheed O. Bolarinwa <refactormyself@xxxxxxxxx>
---
drivers/pci/hotplug/pciehp_hpc.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index b89c9ee4a3b5..39305aabc3a2 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -278,7 +278,7 @@ static void pcie_wait_for_presence(struct pci_dev *pdev)
do {
pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
- if (slot_status & PCI_EXP_SLTSTA_PDS)
+ if ((slot_status != (u16)~0) && (slot_status & PCI_EXP_SLTSTA_PDS))
return;
msleep(10);
timeout -= 10;
@@ -399,6 +399,11 @@ void pciehp_get_power_status(struct controller *ctrl, u8 *status)
ctrl_dbg(ctrl, "%s: SLOTCTRL %x value read %x\n", __func__,
pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_ctrl);
+ if (slot_ctrl == (u16)~0) {
+ *status = 1; /* On */
+ return;
+ }
+
switch (slot_ctrl & PCI_EXP_SLTCTL_PCC) {
case PCI_EXP_SLTCTL_PWR_OFF:
*status = 0; /* Off */
--
2.18.4
