Force-threaded interrupt handlers used to run with interrupts enabled,
something which could lead to deadlocks in case a threaded handler
shared a lock with code running in hard interrupt context (e.g. timer
callbacks) and did not explicitly disable interrupts.
Since commit 81e2073c175b ("genirq: Disable interrupts for force
threaded handlers") interrupt handlers always run with interrupts
disabled on non-RT so that drivers no longer need to do handle forced
threading ("threadirqs").
Drop the now obsolete workaround added by commit a1227f3c1030 ("usb:
ehci: fix deadlock when threadirqs option is used").
Cc: Stanislaw Gruszka <sgruszka@xxxxxxxxxx>
Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
---
drivers/usb/host/ehci-hcd.c | 13 +++----------
1 file changed, 3 insertions(+), 10 deletions(-)
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 1926b328b6aa..403bd3d6991f 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -705,15 +705,8 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd)
struct ehci_hcd *ehci = hcd_to_ehci (hcd);
u32 status, masked_status, pcd_status = 0, cmd;
int bh;
- unsigned long flags;
- /*
- * For threadirqs option we use spin_lock_irqsave() variant to prevent
- * deadlock with ehci hrtimer callback, because hrtimer callbacks run
- * in interrupt context even when threadirqs is specified. We can go
- * back to spin_lock() variant when hrtimer callbacks become threaded.
- */
- spin_lock_irqsave(&ehci->lock, flags);
+ spin_lock(&ehci->lock);
status = ehci_readl(ehci, &ehci->regs->status);
@@ -731,7 +724,7 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd)
/* Shared IRQ? */
if (!masked_status || unlikely(ehci->rh_state == EHCI_RH_HALTED)) {
- spin_unlock_irqrestore(&ehci->lock, flags);
+ spin_unlock(&ehci->lock);
return IRQ_NONE;
}
@@ -842,7 +835,7 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd)
if (bh)
ehci_work (ehci);
- spin_unlock_irqrestore(&ehci->lock, flags);
+ spin_unlock(&ehci->lock);
if (pcd_status)
usb_hcd_poll_rh_status(hcd);
return IRQ_HANDLED;
--
2.26.3
