From: Sean Young sean@mess.org
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 --- drivers/media/rc/gpio-ir-tx.c | 28 +++++++++++++++++++++------- 1 file changed, 21 insertions(+), 7 deletions(-)
--- 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 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(struc 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 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]);