ARM: 5688/1: ks8695_serial: disable_irq() lockup

disable_irq() cannot be called from interrupt context without self imposed deadlock. This was happening in ks8695uart_stop_tx().

Signed-off-by: Dick Hollenbeck <dick@softplc.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/serial/serial_ks8695.c b/drivers/serial/serial_ks8695.c
index e0665630e4da..52db5cc3f900 100644
--- a/drivers/serial/serial_ks8695.c
+++ b/drivers/serial/serial_ks8695.c
@@ -110,7 +110,11 @@ static struct console ks8695_console;
 static void ks8695uart_stop_tx(struct uart_port *port)
 {
         if (tx_enabled(port)) {
-                disable_irq(KS8695_IRQ_UART_TX);
+                /* use disable_irq_nosync() and not disable_irq() to avoid self
+                 * imposed deadlock by not waiting for irq handler to end,
+                 * since this ks8695uart_stop_tx() is called from interrupt context.
+                 */
+                disable_irq_nosync(KS8695_IRQ_UART_TX);
                 tx_enable(port, 0);
         }
 }