xHCI: synchronize irq in xhci_suspend()

Synchronize the interrupts instead of free them in xhci_suspend(). This will
prevent a double free when the host is suspended and then the card removed.

Set the flag hcd->msix_enabled when using MSI-X, and check the flag in
suspend_common(). MSI-X synchronization will be handled by xhci_suspend(),
and MSI/INTx will be synchronized in suspend_common().

This patch should be queued for the 2.6.37 stable tree.

Reported-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@kernel.org

3 files changed, 22 insertions, 32 deletions

diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c
index b55d46070a25..f71e8e307e0f 100644
--- a/drivers/usb/core/hcd-pci.c
+++ b/drivers/usb/core/hcd-pci.c
@@ -405,7 +405,12 @@ static int suspend_common(struct device *dev, bool do_wakeup)
                         return retval;
         }
 
-        synchronize_irq(pci_dev->irq);
+        /* If MSI-X is enabled, the driver will have synchronized all vectors
+         * in pci_suspend(). If MSI or legacy PCI is enabled, that will be
+         * synchronized here.
+         */
+        if (!hcd->msix_enabled)
+                synchronize_irq(pci_dev->irq);
 
         /* Downstream ports from this root hub should already be quiesced, so
          * there will be no DMA activity.  Now we can shut down the upstream
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 45e4a3108cc3..d48edfa5043a 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -226,7 +226,8 @@ static int xhci_setup_msi(struct xhci_hcd *xhci)
 static int xhci_setup_msix(struct xhci_hcd *xhci)
 {
         int i, ret = 0;
-        struct pci_dev *pdev = to_pci_dev(xhci_to_hcd(xhci)->self.controller);
+        struct usb_hcd *hcd = xhci_to_hcd(xhci);
+        struct pci_dev *pdev = to_pci_dev(hcd->self.controller);
 
         /*
          * calculate number of msi-x vectors supported.
@@ -265,6 +266,7 @@ static int xhci_setup_msix(struct xhci_hcd *xhci)
                         goto disable_msix;
         }
 
+        hcd->msix_enabled = 1;
         return ret;
 
 disable_msix:
@@ -280,7 +282,8 @@ free_entries:
 /* Free any IRQs and disable MSI-X */
 static void xhci_cleanup_msix(struct xhci_hcd *xhci)
 {
-        struct pci_dev *pdev = to_pci_dev(xhci_to_hcd(xhci)->self.controller);
+        struct usb_hcd *hcd = xhci_to_hcd(xhci);
+        struct pci_dev *pdev = to_pci_dev(hcd->self.controller);
 
         xhci_free_irq(xhci);
 
@@ -292,6 +295,7 @@ static void xhci_cleanup_msix(struct xhci_hcd *xhci)
                 pci_disable_msi(pdev);
         }
 
+        hcd->msix_enabled = 0;
         return;
 }
 
@@ -647,6 +651,7 @@ int xhci_suspend(struct xhci_hcd *xhci)
         int                     rc = 0;
         struct usb_hcd          *hcd = xhci_to_hcd(xhci);
         u32                     command;
+        int                     i;
 
         spin_lock_irq(&xhci->lock);
         clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
@@ -677,10 +682,15 @@ int xhci_suspend(struct xhci_hcd *xhci)
                 spin_unlock_irq(&xhci->lock);
                 return -ETIMEDOUT;
         }
-        /* step 5: remove core well power */
-        xhci_cleanup_msix(xhci);
         spin_unlock_irq(&xhci->lock);
 
+        /* step 5: remove core well power */
+        /* synchronize irq when using MSI-X */
+        if (xhci->msix_entries) {
+                for (i = 0; i < xhci->msix_count; i++)
+                        synchronize_irq(xhci->msix_entries[i].vector);
+        }
+
         return rc;
 }
 
@@ -694,7 +704,6 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
 {
         u32                     command, temp = 0;
         struct usb_hcd          *hcd = xhci_to_hcd(xhci);
-        struct pci_dev          *pdev = to_pci_dev(hcd->self.controller);
         int     old_state, retval;
 
         old_state = hcd->state;
@@ -729,9 +738,8 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
                 xhci_dbg(xhci, "Stop HCD\n");
                 xhci_halt(xhci);
                 xhci_reset(xhci);
-                if (hibernated)
-                        xhci_cleanup_msix(xhci);
                 spin_unlock_irq(&xhci->lock);
+                xhci_cleanup_msix(xhci);
 
 #ifdef CONFIG_USB_XHCI_HCD_DEBUGGING
                 /* Tell the event ring poll function not to reschedule */
@@ -765,30 +773,6 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
                 return retval;
         }
 
-        spin_unlock_irq(&xhci->lock);
-        /* Re-setup MSI-X */
-        if (hcd->irq)
-                free_irq(hcd->irq, hcd);
-        hcd->irq = -1;
-
-        retval = xhci_setup_msix(xhci);
-        if (retval)
-                /* fall back to msi*/
-                retval = xhci_setup_msi(xhci);
-
-        if (retval) {
-                /* fall back to legacy interrupt*/
-                retval = request_irq(pdev->irq, &usb_hcd_irq, IRQF_SHARED,
-                                        hcd->irq_descr, hcd);
-                if (retval) {
-                        xhci_err(xhci, "request interrupt %d failed\n",
-                                        pdev->irq);
-                        return retval;
-                }
-                hcd->irq = pdev->irq;
-        }
-
-        spin_lock_irq(&xhci->lock);
         /* step 4: set Run/Stop bit */
         command = xhci_readl(xhci, &xhci->op_regs->command);
         command |= CMD_RUN;
diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
index dd6ee49a0844..a854fe89484e 100644
--- a/include/linux/usb/hcd.h
+++ b/include/linux/usb/hcd.h
@@ -112,6 +112,7 @@ struct usb_hcd {
         /* Flags that get set only during HCD registration or removal. */
         unsigned                rh_registered:1;/* is root hub registered? */
         unsigned                rh_pollable:1;  /* may we poll the root hub? */
+        unsigned                msix_enabled:1; /* driver has MSI-X enabled? */
 
         /* The next flag is a stopgap, to be removed when all the HCDs
          * support the new root-hub polling mechanism. */