ipack/devices/ipoctal: protect the channel data processing with a spinlock

We protect important data such as TX buffer pointer, nb_bytes counter and status
registers of the device, from accessing several times at the same time.

Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/ipack/devices/ipoctal.c b/drivers/ipack/devices/ipoctal.c
index 9cd5572457ff..5ce2c4c5bb32 100644
--- a/drivers/ipack/devices/ipoctal.c
+++ b/drivers/ipack/devices/ipoctal.c
@@ -191,6 +191,8 @@ static void ipoctal_irq_channel(struct ipoctal_channel *channel)
         tty = tty_port_tty_get(&channel->tty_port);
         if (!tty)
                 return;
+
+        spin_lock(&channel->lock);
         /* The HW is organized in pair of channels.  See which register we need
          * to read from */
         isr = ioread8(&channel->block_regs->r.isr);
@@ -216,6 +218,7 @@ static void ipoctal_irq_channel(struct ipoctal_channel *channel)
 
         tty_flip_buffer_push(tty);
         tty_kref_put(tty);
+        spin_unlock(&channel->lock);
 }
 
 static irqreturn_t ipoctal_irq_handler(void *arg)