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| author | Sean Young <sean@mess.org> | 2020-05-02 14:50:52 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-09-03 11:24:23 +0200 |
| commit | 0961d7fe12491b474546952e25b441b9e56915c6 (patch) | |
| tree | dc350525f0ecf40a28e7674c96d233698ed25b8c /drivers/media/rc | |
| parent | 70323cca909d68ec88d44141a357b4c77e194492 (diff) | |
| download | linux-stable-0961d7fe12491b474546952e25b441b9e56915c6.tar.gz linux-stable-0961d7fe12491b474546952e25b441b9e56915c6.tar.bz2 linux-stable-0961d7fe12491b474546952e25b441b9e56915c6.zip | |
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>
Diffstat (limited to 'drivers/media/rc')
| -rw-r--r-- | drivers/media/rc/gpio-ir-tx.c | 7 |
1 files changed, 1 insertions, 6 deletions
diff --git a/drivers/media/rc/gpio-ir-tx.c b/drivers/media/rc/gpio-ir-tx.c index cd476cab9782..4e70b67ccd18 100644 --- a/drivers/media/rc/gpio-ir-tx.c +++ b/drivers/media/rc/gpio-ir-tx.c @@ -87,13 +87,8 @@ 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]); |