Commit ea8912b7 authored by Sean Young's avatar Sean Young Committed by Mauro Carvalho Chehab
Browse files

media: gpio-ir-tx: improve precision of transmitted signal due to scheduling 



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: default avatarSean Young <sean@mess.org>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+huawei@kernel.org>
parent 0e06a071

drivers/media/rc/gpio-ir-tx.c

+1 −6
Original line number Diff line number Diff line
@@ -79,13 +79,8 @@ static int gpio_ir_tx(struct rc_dev *dev, unsigned int *txbuf, 
			// 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]);