[269/272] xHCI: synchronize irq in xhci_suspend()

Greg KH
2011-02-16T00:27:06Z

From: Andiry Xu <andiry.xu@amd.com>

commit 0029227f1bc30b6c809ae751f9e7af6cef900997 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/usb/core/hcd-pci.c | 7 +++++-
drivers/usb/host/xhci.c | 46 ++++++++++++++-------------------------------
include/linux/usb/hcd.h | 1
3 files changed, 22 insertions(+), 32 deletions(-)

--- a/drivers/usb/core/hcd-pci.c
+++ b/drivers/usb/core/hcd-pci.c
@@ -406,7 +406,12 @@ static int suspend_common(struct device
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
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -226,7 +226,8 @@ static int xhci_setup_msi(struct xhci_hc
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_h
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 xhc
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, b
{
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, b
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, b
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;
--- 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. */