@@ -126,7 +126,7 @@ static int pwm_imx27_wait_fifo_empty(struct pwm_chip *chip,
struct device *dev = chip->dev;
unsigned int period_ms = DIV_ROUND_UP_ULL(pwm->state.period, NSEC_PER_MSEC);
int tries = MX3_PWM_FIFOAV_EMPTY_LOOP;
- int fifoav;
+ int fifoav, previous_fifoav = INT_MAX;
u32 sr;
while (tries--) {
@@ -134,6 +134,10 @@ static int pwm_imx27_wait_fifo_empty(struct pwm_chip *chip,
fifoav = FIELD_GET(MX3_PWMSR_FIFOAV, sr);
if (fifoav == MX3_PWMSR_FIFOAV_EMPTY)
return;
+ /* if the FIFO value does not decrease, there is another problem */
+ if (previous_fifoav == fifoav)
+ break;
+ previous_fifoav = fifoav;
msleep(period_ms);
}
dev_warn(dev, "FIFO has been refilled concurrently\n");
Avoid unnecessary sleeps as adviced[0], if the FIFO cannot be emptied. [0] https://lore.kernel.org/lkml/20230310174517.rb7xxrougkse2lrc@pengutronix.de/T/#ec9560c1f613d9c0d7b77d72ad9051768812f80db Signed-off-by: Leif Middelschulte <Leif.Middelschulte@gmail.com> --- drivers/pwm/pwm-imx27.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)