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USB: xhci: drop workaround for forced irq threading

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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 81e2073c17 ("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 63aea0dbab ("USB:
xhci: fix lock-inversion problem").

Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210322111140.32056-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Johan Hovold 2021-03-22 12:11:40 +01:00 committed by Greg Kroah-Hartman
parent 6fcf11295e
commit 5e7121723d
1 changed files with 2 additions and 3 deletions
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5
drivers/usb/host/xhci-ring.c
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@ -3014,12 +3014,11 @@ irqreturn_t xhci_irq(struct usb_hcd *hcd)
struct xhci_hcd *xhci = hcd_to_xhci(hcd); struct xhci_hcd *xhci = hcd_to_xhci(hcd);
union xhci_trb *event_ring_deq; union xhci_trb *event_ring_deq;
irqreturn_t ret = IRQ_NONE; irqreturn_t ret = IRQ_NONE;
unsigned long flags;
u64 temp_64; u64 temp_64;
u32 status; u32 status;
int event_loop = 0; int event_loop = 0;
spin_lock_irqsave(&xhci->lock, flags); spin_lock(&xhci->lock);
/* Check if the xHC generated the interrupt, or the irq is shared */ /* Check if the xHC generated the interrupt, or the irq is shared */
status = readl(&xhci->op_regs->status); status = readl(&xhci->op_regs->status);
if (status == ~(u32)0) { if (status == ~(u32)0) {
@ -3082,7 +3081,7 @@ irqreturn_t xhci_irq(struct usb_hcd *hcd)
ret = IRQ_HANDLED; ret = IRQ_HANDLED;
out: out:
spin_unlock_irqrestore(&xhci->lock, flags); spin_unlock(&xhci->lock);
return ret; return ret;
} }