57 lines
1.8 KiB
Diff
57 lines
1.8 KiB
Diff
ehci_irq() and ehci_hrtimer_func() can deadlock on ehci->lock when
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threadirqs option is used. To prevent the deadlock use
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spin_lock_irqsave() in ehci_irq().
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This change can be reverted when hrtimer callbacks become threaded.
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Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
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---
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drivers/usb/host/ehci-hcd.c | 13 ++++++++++---
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1 file changed, 10 insertions(+), 3 deletions(-)
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diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
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index 4711427..0bc6410 100644
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--- a/drivers/usb/host/ehci-hcd.c
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+++ b/drivers/usb/host/ehci-hcd.c
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@@ -685,8 +685,15 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd)
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struct ehci_hcd *ehci = hcd_to_ehci (hcd);
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u32 status, masked_status, pcd_status = 0, cmd;
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int bh;
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+ unsigned long flags;
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- spin_lock (&ehci->lock);
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+ /*
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+ * For threadirqs option we use spin_lock_irqsave() variant to prevent
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+ * deadlock with ehci hrtimer callback, because hrtimer callbacks run
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+ * in interrupt context even when threadirqs is specified. We can go
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+ * back to spin_lock() variant when hrtimer callbacks become threaded.
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+ */
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+ spin_lock_irqsave(&ehci->lock, flags);
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status = ehci_readl(ehci, &ehci->regs->status);
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@@ -704,7 +711,7 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd)
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/* Shared IRQ? */
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if (!masked_status || unlikely(ehci->rh_state == EHCI_RH_HALTED)) {
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- spin_unlock(&ehci->lock);
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+ spin_unlock_irqrestore(&ehci->lock, flags);
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return IRQ_NONE;
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}
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@@ -815,7 +822,7 @@ dead:
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if (bh)
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ehci_work (ehci);
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- spin_unlock (&ehci->lock);
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+ spin_unlock_irqrestore(&ehci->lock, flags);
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if (pcd_status)
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usb_hcd_poll_rh_status(hcd);
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return IRQ_HANDLED;
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--
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1.7.11.7
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--
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