[PATCH] serial/amba-pl011: Disable interrupts around TX softirq

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



pl011_tx_softirq() currently uses spin_{,un}lock(), which are not
sufficient to inhibit pl011_int() from being triggered by a local
IRQ and trying to re-take the same lock.  This can lead to
deadlocks.

This patch uses the _irq() locking variants instead to ensure that
pl011_int() handling for a given port is deferred until any
pl011_tx_softirq() work for that port is complete.

Fixes: 734745caeb9f serial/amba-pl011: Activate TX IRQ passively
Signed-off-by: Dave Martin <Dave.Martin@xxxxxxx>
Tested-by: Robin Murphy <robin.murphy@xxxxxxx>
Tested-by: Stefan Wahren <stefan.wahren@xxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx> # 4.1
---
 drivers/tty/serial/amba-pl011.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 763eb20..0cc622a 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -1360,9 +1360,9 @@ static void pl011_tx_softirq(struct work_struct *work)
 	struct uart_amba_port *uap =
 		container_of(dwork, struct uart_amba_port, tx_softirq_work);
 
-	spin_lock(&uap->port.lock);
+	spin_lock_irq(&uap->port.lock);
 	while (pl011_tx_chars(uap)) ;
-	spin_unlock(&uap->port.lock);
+	spin_unlock_irq(&uap->port.lock);
 }
 
 static void pl011_tx_irq_seen(struct uart_amba_port *uap)
-- 
1.7.10.4

--
To unsubscribe from this list: send the line "unsubscribe linux-serial" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Kernel Newbies]     [Security]     [Netfilter]     [Bugtraq]     [Linux PPP]     [Linux FS]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Video 4 Linux]     [Linmodem]     [Device Mapper]     [Linux Kernel for ARM]

  Powered by Linux