On Monday, December 27, 2010, Andiry Xu wrote:
> 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().
>
> Reported-by: Matthew Garrett <mjg@xxxxxxxxxx>
> Signed-off-by: Andiry Xu <andiry.xu@xxxxxxx>
Looks good, but you need to remove the xhci_cleanup_msix() from under
the spinlock in _stop() and _shutdown() too.
Thanks,
Rafael
> ---
> 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(-)
>
> diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c
> index 3799573..4de52dc 100644
> --- a/drivers/usb/core/hcd-pci.c
> +++ b/drivers/usb/core/hcd-pci.c
> @@ -406,7 +406,12 @@ 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 45e4a31..d48edfa 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 0b6e751..6c37d78 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. */
>
--
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