diff options
| author | Sean Young <sean@mess.org> | 2022-02-20 17:28:24 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-08 15:23:02 +0300 |
| commit | 0a45148635f8f5d4b26e8c1a0e69719605914eb3 (patch) | |
| tree | ee2598e89d26d545f927880a2c76b78657feae57 /drivers/media | |
| parent | 3e3c8d88e0caadb4ff9c8e8e8ec95590f91546f5 (diff) | |
| download | linux-0a45148635f8f5d4b26e8c1a0e69719605914eb3.tar.xz | |
media: gpio-ir-tx: fix transmit with long spaces on Orange Pi PC
commit 5ad05ecad4326ddaa26a83ba2233a67be24c1aaa upstream.
Calling udelay for than 1000us does not always yield the correct
results.
Cc: stable@vger.kernel.org
Reported-by: Михаил <vrserver1@gmail.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/media')
| -rw-r--r-- | drivers/media/rc/gpio-ir-tx.c | 28 |
1 files changed, 21 insertions, 7 deletions
diff --git a/drivers/media/rc/gpio-ir-tx.c b/drivers/media/rc/gpio-ir-tx.c index c6cd2e6d8e65..a50701cfbbd7 100644 --- a/drivers/media/rc/gpio-ir-tx.c +++ b/drivers/media/rc/gpio-ir-tx.c @@ -48,11 +48,29 @@ static int gpio_ir_tx_set_carrier(struct rc_dev *dev, u32 carrier) return 0; } +static void delay_until(ktime_t until) +{ + /* + * delta should never exceed 0.5 seconds (IR_MAX_DURATION) and on + * m68k ndelay(s64) does not compile; so use s32 rather than s64. + */ + s32 delta; + + while (true) { + delta = ktime_us_delta(until, ktime_get()); + if (delta <= 0) + return; + + /* udelay more than 1ms may not work */ + delta = min(delta, 1000); + udelay(delta); + } +} + static void gpio_ir_tx_unmodulated(struct gpio_ir *gpio_ir, uint *txbuf, uint count) { ktime_t edge; - s32 delta; int i; local_irq_disable(); @@ -63,9 +81,7 @@ static void gpio_ir_tx_unmodulated(struct gpio_ir *gpio_ir, uint *txbuf, gpiod_set_value(gpio_ir->gpio, !(i % 2)); edge = ktime_add_us(edge, txbuf[i]); - delta = ktime_us_delta(edge, ktime_get()); - if (delta > 0) - udelay(delta); + delay_until(edge); } gpiod_set_value(gpio_ir->gpio, 0); @@ -97,9 +113,7 @@ static void gpio_ir_tx_modulated(struct gpio_ir *gpio_ir, uint *txbuf, if (i % 2) { // space edge = ktime_add_us(edge, txbuf[i]); - delta = ktime_us_delta(edge, ktime_get()); - if (delta > 0) - udelay(delta); + delay_until(edge); } else { // pulse ktime_t last = ktime_add_us(edge, txbuf[i]); |