I found the problem that the present bit does not be cleared
though the slot is empty.
Step to reproduce:
# cd /sys/bus/pci/slots/66
# cat adapter
0
--- (insert PCIe card on slot#66) ---
# cat adapter
1
# echo 1 > power
# echo 0 > power
--- (eject PCIe card on slot#66) ---
# cat adapter
1
==> should be 0.
According to git-bisect this is caused by:
2debd9289997fc5d1c0043b41201a8b40d5e11d0
PCI: pciehp: Disable/enable link during slot power off/on
is the first bad commit
By reverting the above patch, this bug can be solved.
And I also found this can be fixed by changing the timing of link-disable
during power off the slot.
So, this patch changes the timing of link-disable during power off.
Signed-off-by: Taku Izumi <izumi.taku@xxxxxxxxxxxxxx>
---
drivers/pci/hotplug/pciehp_hpc.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 14acfcc..163f0b4 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -508,7 +508,12 @@ void pciehp_power_off_slot(struct slot * slot)
{
struct controller *ctrl = slot->ctrl;
- /* Disable the link at first */
+ pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_OFF, PCI_EXP_SLTCTL_PCC);
+ ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
+ pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
+ PCI_EXP_SLTCTL_PWR_OFF);
+
+ /* Disable the link */
pciehp_link_disable(ctrl);
/* wait the link is down */
if (ctrl->link_active_reporting)
@@ -516,10 +521,6 @@ void pciehp_power_off_slot(struct slot * slot)
else
msleep(1000);
- pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_OFF, PCI_EXP_SLTCTL_PCC);
- ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
- pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
- PCI_EXP_SLTCTL_PWR_OFF);
}
static irqreturn_t pcie_isr(int irq, void *dev_id)
--
1.8.3.1
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