PCI/PCIe: Clear Root PME Status bits early during system resume

I noticed that PCI Express PMEs don't work on my Toshiba Portege R500
after the system has been woken up from a sleep state by a PME
(through Wake-on-LAN).  After some investigation it turned out that
the BIOS didn't clear the Root PME Status bit in the root port that
received the wakeup PME and since the Requester ID was also set in
the port's Root Status register, any subsequent PMEs didn't trigger
interrupts.

This problem can be avoided by clearing the Root PME Status bits in
all PCI Express root ports during early resume.  For this purpose,
add an early resume routine to the PCIe port driver and make this
driver be always registered, even if pci_ports_disable is set (in
which case the driver's only function is to provide the early
resume callback).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 4 insertions, 23 deletions

diff --git a/drivers/pci/pcie/pme.c b/drivers/pci/pcie/pme.c
index 2f3c90407227..073f0308c6b2 100644
--- a/drivers/pci/pcie/pme.c
+++ b/drivers/pci/pcie/pme.c
@@ -26,9 +26,6 @@
 #include "../pci.h"
 #include "portdrv.h"
 
-#define PCI_EXP_RTSTA_PME       0x10000 /* PME status */
-#define PCI_EXP_RTSTA_PENDING   0x20000 /* PME pending */
-
 /*
  * If this switch is set, MSI will not be used for PCIe PME signaling.  This
  * causes the PCIe port driver to use INTx interrupts only, but it turns out
@@ -74,22 +71,6 @@ void pcie_pme_interrupt_enable(struct pci_dev *dev, bool enable)
 }
 
 /**
- * pcie_pme_clear_status - Clear root port PME interrupt status.
- * @dev: PCIe root port or event collector.
- */
-static void pcie_pme_clear_status(struct pci_dev *dev)
-{
-        int rtsta_pos;
-        u32 rtsta;
-
-        rtsta_pos = pci_pcie_cap(dev) + PCI_EXP_RTSTA;
-
-        pci_read_config_dword(dev, rtsta_pos, &rtsta);
-        rtsta |= PCI_EXP_RTSTA_PME;
-        pci_write_config_dword(dev, rtsta_pos, rtsta);
-}
-
-/**
  * pcie_pme_walk_bus - Scan a PCI bus for devices asserting PME#.
  * @bus: PCI bus to scan.
  *
@@ -253,7 +234,7 @@ static void pcie_pme_work_fn(struct work_struct *work)
                          * Clear PME status of the port.  If there are other
                          * pending PMEs, the status will be set again.
                          */
-                        pcie_pme_clear_status(port);
+                        pcie_clear_root_pme_status(port);
 
                         spin_unlock_irq(&data->lock);
                         pcie_pme_handle_request(port, rtsta & 0xffff);
@@ -378,7 +359,7 @@ static int pcie_pme_probe(struct pcie_device *srv)
 
         port = srv->port;
         pcie_pme_interrupt_enable(port, false);
-        pcie_pme_clear_status(port);
+        pcie_clear_root_pme_status(port);
 
         ret = request_irq(srv->irq, pcie_pme_irq, IRQF_SHARED, "PCIe PME", srv);
         if (ret) {
@@ -402,7 +383,7 @@ static int pcie_pme_suspend(struct pcie_device *srv)
 
         spin_lock_irq(&data->lock);
         pcie_pme_interrupt_enable(port, false);
-        pcie_pme_clear_status(port);
+        pcie_clear_root_pme_status(port);
         data->noirq = true;
         spin_unlock_irq(&data->lock);
 
@@ -422,7 +403,7 @@ static int pcie_pme_resume(struct pcie_device *srv)
 
         spin_lock_irq(&data->lock);
         data->noirq = false;
-        pcie_pme_clear_status(port);
+        pcie_clear_root_pme_status(port);
         pcie_pme_interrupt_enable(port, true);
         spin_unlock_irq(&data->lock);