Commit 5e712172 authored by Johan Hovold's avatar Johan Hovold Committed by Greg Kroah-Hartman
Browse files

USB: xhci: drop workaround for forced irq threading 



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 81e2073c ("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 63aea0db ("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: default avatarJohan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210322111140.32056-1-johan@kernel.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 6fcf1129

drivers/usb/host/xhci-ring.c

+2 −3
Original line number Diff line number Diff line
@@ -3014,12 +3014,11 @@ irqreturn_t xhci_irq(struct usb_hcd *hcd) 
	struct xhci_hcd *xhci = hcd_to_xhci(hcd);

	union xhci_trb *event_ring_deq;

	irqreturn_t ret = IRQ_NONE;

	unsigned long flags;

	u64 temp_64;

	u32 status;

	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 */

	status = readl(&xhci->op_regs->status);

	if (status == ~(u32)0) {
@@ -3082,7 +3081,7 @@ irqreturn_t xhci_irq(struct usb_hcd *hcd) 
	ret = IRQ_HANDLED;



out:

	spin_unlock_irqrestore(&xhci->lock, flags);

	spin_unlock(&xhci->lock);



	return ret;

}