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media: gpio-ir-tx: fix transmit with long spaces on Orange Pi PC

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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>
This commit is contained in:
Sean Young
2022-02-20 15:28:24 +01:00
committed by Greg Kroah-Hartman
parent 785ffce44a
commit cde90e8291
1 changed files with 21 additions and 7 deletions
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28
drivers/media/rc/gpio-ir-tx.c
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@@ -48,11 +48,29 @@ static int gpio_ir_tx_set_carrier(struct rc_dev *dev, u32 carrier)
return 0; 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, static void gpio_ir_tx_unmodulated(struct gpio_ir *gpio_ir, uint *txbuf,
uint count) uint count)
{ {
ktime_t edge; ktime_t edge;
s32 delta;
int i; int i;
local_irq_disable(); 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)); gpiod_set_value(gpio_ir->gpio, !(i % 2));
edge = ktime_add_us(edge, txbuf[i]); edge = ktime_add_us(edge, txbuf[i]);
delta = ktime_us_delta(edge, ktime_get()); delay_until(edge);
if (delta > 0)
udelay(delta);
} }
gpiod_set_value(gpio_ir->gpio, 0); 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) { if (i % 2) {
// space // space
edge = ktime_add_us(edge, txbuf[i]); edge = ktime_add_us(edge, txbuf[i]);
delta = ktime_us_delta(edge, ktime_get()); delay_until(edge);
if (delta > 0)
udelay(delta);
} else { } else {
// pulse // pulse
ktime_t last = ktime_add_us(edge, txbuf[i]); ktime_t last = ktime_add_us(edge, txbuf[i]);