media: gpio-ir-tx: improve precision of transmitted signal due to scheduling
[ Upstream commit ea8912b788f8144e7d32ee61e5ccba45424bef83 ]
usleep_range() may take longer than the max argument due to scheduling,
especially under load. This is causing random errors in the transmitted
IR. Remove the usleep_range() in favour of busy-looping with udelay().
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
diff --git a/drivers/media/rc/gpio-ir-tx.c b/drivers/media/rc/gpio-ir-tx.c
index cd476ca..4e70b67 100644
--- a/drivers/media/rc/gpio-ir-tx.c
+++ b/drivers/media/rc/gpio-ir-tx.c
@@ -87,13 +87,8 @@
// space
edge = ktime_add_us(edge, txbuf[i]);
delta = ktime_us_delta(edge, ktime_get());
- if (delta > 10) {
- spin_unlock_irqrestore(&gpio_ir->lock, flags);
- usleep_range(delta, delta + 10);
- spin_lock_irqsave(&gpio_ir->lock, flags);
- } else if (delta > 0) {
+ if (delta > 0)
udelay(delta);
- }
} else {
// pulse
ktime_t last = ktime_add_us(edge, txbuf[i]);