| Message ID | 20230815104332.55044-4-Leif.Middelschulte@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3,1/4] pwm: imx27: fix race condition .apply,.get_state | expand |
On Tue, Aug 15, 2023 at 12:43:32PM +0200, Leif Middelschulte wrote: > Instead of issuing a warning, return an error (as adviced[0]), if the > FIFO cannot be cleanly set up. > > [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 | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/drivers/pwm/pwm-imx27.c b/drivers/pwm/pwm-imx27.c > index 9673e809d212..5fd6d34a7722 100644 > --- a/drivers/pwm/pwm-imx27.c > +++ b/drivers/pwm/pwm-imx27.c > @@ -133,14 +133,15 @@ static int pwm_imx27_wait_fifo_empty(struct pwm_chip *chip, > sr = readl(imx->mmio_base + MX3_PWMSR); > fifoav = FIELD_GET(MX3_PWMSR_FIFOAV, sr); > if (fifoav == MX3_PWMSR_FIFOAV_EMPTY) > - return; > + return 0; > /* 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"); > + > + return -EAGAIN; > } > > static int pwm_imx27_get_state(struct pwm_chip *chip, > @@ -208,7 +209,9 @@ static int pwm_imx27_get_state(struct pwm_chip *chip, > * been supplied and a period expired between the call of the wait > * function and the subsequent readl. > */ > - pwm_imx27_wait_fifo_empty(chip, pwm); > + ret = pwm_imx27_wait_fifo_empty(chip, pwm); > + if (ret) > + return ret; > val = readl(imx->mmio_base + MX3_PWMSAR); > } else { > val = imx->duty_cycle; I'd squash this into the patch introducing pwm_imx27_wait_fifo_empty, too. Best regards Uwe
diff --git a/drivers/pwm/pwm-imx27.c b/drivers/pwm/pwm-imx27.c index 9673e809d212..5fd6d34a7722 100644 --- a/drivers/pwm/pwm-imx27.c +++ b/drivers/pwm/pwm-imx27.c @@ -133,14 +133,15 @@ static int pwm_imx27_wait_fifo_empty(struct pwm_chip *chip, sr = readl(imx->mmio_base + MX3_PWMSR); fifoav = FIELD_GET(MX3_PWMSR_FIFOAV, sr); if (fifoav == MX3_PWMSR_FIFOAV_EMPTY) - return; + return 0; /* 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"); + + return -EAGAIN; } static int pwm_imx27_get_state(struct pwm_chip *chip, @@ -208,7 +209,9 @@ static int pwm_imx27_get_state(struct pwm_chip *chip, * been supplied and a period expired between the call of the wait * function and the subsequent readl. */ - pwm_imx27_wait_fifo_empty(chip, pwm); + ret = pwm_imx27_wait_fifo_empty(chip, pwm); + if (ret) + return ret; val = readl(imx->mmio_base + MX3_PWMSAR); } else { val = imx->duty_cycle;
Instead of issuing a warning, return an error (as adviced[0]), if the FIFO cannot be cleanly set up. [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 | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)