From: Johan Hovold <johan@kernel.org>
To: Mathias Nyman <mathias.nyman@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
Johan Hovold <johan@kernel.org>,
Alan Stern <stern@rowland.harvard.edu>,
Bart Van Assche <bart.vanassche@sandisk.com>,
Thomas Gleixner <tglx@linutronix.de>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>
Subject: [PATCH] USB: xhci: drop workaround for forced irq threading
Date: Mon, 22 Mar 2021 12:11:40 +0100 [thread overview]
Message-ID: <20210322111140.32056-1-johan@kernel.org> (raw)
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 63aea0dbab90 ("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>
---
drivers/usb/host/xhci-ring.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index ce38076901e2..20f5ded29b3b 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -3015,12 +3015,11 @@ 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) {
@@ -3083,7 +3082,7 @@ irqreturn_t xhci_irq(struct usb_hcd *hcd)
ret = IRQ_HANDLED;
out:
- spin_unlock_irqrestore(&xhci->lock, flags);
+ spin_unlock(&xhci->lock);
return ret;
}
--
2.26.3
reply other threads:[~2021-03-22 11:12 UTC|newest]
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