PCI: pciehp: Clear Presence Detect and Data Link Layer Status Changed on resume

BugLink: http://bugs.launchpad.net/bugs/1807469
commit 13c65840feab8109194f9490c9870587173cb29d upstream.

After a suspend/resume cycle the Presence Detect or Data Link Layer Status
Changed bits might be set.  If we don't clear them those events will not
fire anymore and nothing happens for instance when a device is now
hot-unplugged.

Fix this by clearing those bits in a newly introduced function
pcie_reenable_notification().  This should be fine because immediately
after, we check if the adapter is still present by reading directly from
the status register.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h
index 06109d40c4ac92168470382ab4ba5e740382b4d4..e7d6cfaf386581a7d89541c89298d235bde752d6 100644 (file)
--- a/drivers/pci/hotplug/pciehp.h
+++ b/drivers/pci/hotplug/pciehp.h
@@ -134,7 +134,7 @@ struct controller *pcie_init(struct pcie_device *dev);
 int pcie_init_notification(struct controller *ctrl);
 int pciehp_enable_slot(struct slot *p_slot);
 int pciehp_disable_slot(struct slot *p_slot);
-void pcie_enable_notification(struct controller *ctrl);
+void pcie_reenable_notification(struct controller *ctrl);
 int pciehp_power_on_slot(struct slot *slot);
 void pciehp_power_off_slot(struct slot *slot);
 void pciehp_get_power_status(struct slot *slot, u8 *status);

diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c
index 35d84845d5af93769c5062ccf1395c467e29d8fe..1288289cc85d38fa09190586f7743ac1271e5a83 100644 (file)
--- a/drivers/pci/hotplug/pciehp_core.c
+++ b/drivers/pci/hotplug/pciehp_core.c
@@ -297,7 +297,7 @@ static int pciehp_resume(struct pcie_device *dev)
        ctrl = get_service_data(dev);
 
        /* reinitialize the chipset's event detection logic */
-       pcie_enable_notification(ctrl);
+       pcie_reenable_notification(ctrl);
 
        slot = ctrl->slot;
 

diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index a89d8b99022864c79bcb68913f77ddfd84b97bf8..8e653ffbda07b375d658c5e33b7bc6bda323f433 100644 (file)
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -673,7 +673,7 @@ static irqreturn_t pcie_isr(int irq, void *dev_id)
        return handled;
 }
 
-void pcie_enable_notification(struct controller *ctrl)
+static void pcie_enable_notification(struct controller *ctrl)
 {
        u16 cmd, mask;
 
@@ -711,6 +711,17 @@ void pcie_enable_notification(struct controller *ctrl)
                 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, cmd);
 }
 
+void pcie_reenable_notification(struct controller *ctrl)
+{
+       /*
+        * Clear both Presence and Data Link Layer Changed to make sure
+        * those events still fire after we have re-enabled them.
+        */
+       pcie_capability_write_word(ctrl->pcie->port, PCI_EXP_SLTSTA,
+                                  PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC);
+       pcie_enable_notification(ctrl);
+}
+
 static void pcie_disable_notification(struct controller *ctrl)
 {
        u16 mask;