1 files changed, 29 insertions, 4 deletions

diff --git a/drivers/media/rc/ir-lirc-codec.c b/drivers/media/rc/ir-lirc-codec.c
index d2fd064474aa..6ad4a0770613 100644
--- a/drivers/media/rc/ir-lirc-codec.c
+++ b/drivers/media/rc/ir-lirc-codec.c
@@ -107,6 +107,12 @@ static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
         unsigned int *txbuf; /* buffer with values to transmit */
         ssize_t ret = -EINVAL;
         size_t count;
+        ktime_t start;
+        s64 towait;
+        unsigned int duration = 0; /* signal duration in us */
+        int i;
+
+        start = ktime_get();
 
         lirc = lirc_get_pdata(file);
         if (!lirc)
@@ -129,11 +135,30 @@ static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
                 goto out;
         }
 
-        if (dev->tx_ir)
-                ret = dev->tx_ir(dev, txbuf, count);
+        if (!dev->tx_ir) {
+                ret = -ENOSYS;
+                goto out;
+        }
+
+        ret = dev->tx_ir(dev, txbuf, (u32)n);
+        if (ret < 0)
+                goto out;
+
+        for (i = 0; i < ret; i++)
+                duration += txbuf[i];
 
-        if (ret > 0)
-                ret *= sizeof(unsigned);
+        ret *= sizeof(unsigned int);
+
+        /*
+         * The lircd gap calculation expects the write function to
+         * wait for the actual IR signal to be transmitted before
+         * returning.
+         */
+        towait = ktime_us_delta(ktime_add_us(start, duration), ktime_get());
+        if (towait > 0) {
+                set_current_state(TASK_INTERRUPTIBLE);
+                schedule_timeout(usecs_to_jiffies(towait));
+        }
 
 out:
         kfree(txbuf);