* [PATCH 1/2] pwm: rcar: Drop useless call to pwm_get_state
@ 2019-10-24 7:14 Uwe Kleine-König
2019-10-24 7:14 ` [PATCH 2/2] pwm: rcar: Document inability to set duty_cycle = 0 Uwe Kleine-König
2019-10-24 7:20 ` [PATCH 1/2] pwm: rcar: Drop useless call to pwm_get_state Yoshihiro Shimoda
0 siblings, 2 replies; 4+ messages in thread
From: Uwe Kleine-König @ 2019-10-24 7:14 UTC (permalink / raw)
To: Thierry Reding, Yoshihiro Shimoda; +Cc: linux-pwm, kernel
pwm_get_state has no side effects and the resulting pwm_state is unused.
So drop the call to pwm_get_state and the local variable from
rcar_pwm_apply().
The call was introduced in commit 7f68ce8287d3 ("pwm: rcar: Add support
"atomic" API") and already then was useless.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
drivers/pwm/pwm-rcar.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/drivers/pwm/pwm-rcar.c b/drivers/pwm/pwm-rcar.c
index 852eb2347954..6fac8eb98d54 100644
--- a/drivers/pwm/pwm-rcar.c
+++ b/drivers/pwm/pwm-rcar.c
@@ -161,11 +161,9 @@ static int rcar_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
const struct pwm_state *state)
{
struct rcar_pwm_chip *rp = to_rcar_pwm_chip(chip);
- struct pwm_state cur_state;
int div, ret;
/* This HW/driver only supports normal polarity */
- pwm_get_state(pwm, &cur_state);
if (state->polarity != PWM_POLARITY_NORMAL)
return -ENOTSUPP;
--
2.23.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH 2/2] pwm: rcar: Document inability to set duty_cycle = 0
2019-10-24 7:14 [PATCH 1/2] pwm: rcar: Drop useless call to pwm_get_state Uwe Kleine-König
@ 2019-10-24 7:14 ` Uwe Kleine-König
2019-10-24 7:20 ` Yoshihiro Shimoda
2019-10-24 7:20 ` [PATCH 1/2] pwm: rcar: Drop useless call to pwm_get_state Yoshihiro Shimoda
1 sibling, 1 reply; 4+ messages in thread
From: Uwe Kleine-König @ 2019-10-24 7:14 UTC (permalink / raw)
To: Thierry Reding, Yoshihiro Shimoda; +Cc: linux-pwm, kernel
When .apply is called with state->duty_cycle = 0 the duty_ns parameter
to rcar_pwm_set_counter() is 0 which results in ph being 0 and
rcar_pwm_set_counter() returning -EINVAL.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
drivers/pwm/pwm-rcar.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/pwm/pwm-rcar.c b/drivers/pwm/pwm-rcar.c
index 6fac8eb98d54..2685577b6dd4 100644
--- a/drivers/pwm/pwm-rcar.c
+++ b/drivers/pwm/pwm-rcar.c
@@ -3,6 +3,9 @@
* R-Car PWM Timer driver
*
* Copyright (C) 2015 Renesas Electronics Corporation
+ *
+ * Limitations:
+ * - The hardware cannot generate a 0% duty cycle.
*/
#include <linux/clk.h>
--
2.23.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* RE: [PATCH 1/2] pwm: rcar: Drop useless call to pwm_get_state
2019-10-24 7:14 [PATCH 1/2] pwm: rcar: Drop useless call to pwm_get_state Uwe Kleine-König
2019-10-24 7:14 ` [PATCH 2/2] pwm: rcar: Document inability to set duty_cycle = 0 Uwe Kleine-König
@ 2019-10-24 7:20 ` Yoshihiro Shimoda
1 sibling, 0 replies; 4+ messages in thread
From: Yoshihiro Shimoda @ 2019-10-24 7:20 UTC (permalink / raw)
To: Uwe Kleine-König, Thierry Reding; +Cc: linux-pwm, kernel
Hi Uwe,
> From: Uwe Kleine-Konig, Sent: Thursday, October 24, 2019 4:14 PM
>
> pwm_get_state has no side effects and the resulting pwm_state is unused.
> So drop the call to pwm_get_state and the local variable from
> rcar_pwm_apply().
>
> The call was introduced in commit 7f68ce8287d3 ("pwm: rcar: Add support
> "atomic" API") and already then was useless.
>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Thank you for the patch!
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Best regards,
Yoshihiro Shimoda
^ permalink raw reply [flat|nested] 4+ messages in thread
* RE: [PATCH 2/2] pwm: rcar: Document inability to set duty_cycle = 0
2019-10-24 7:14 ` [PATCH 2/2] pwm: rcar: Document inability to set duty_cycle = 0 Uwe Kleine-König
@ 2019-10-24 7:20 ` Yoshihiro Shimoda
0 siblings, 0 replies; 4+ messages in thread
From: Yoshihiro Shimoda @ 2019-10-24 7:20 UTC (permalink / raw)
To: Uwe Kleine-König, Thierry Reding; +Cc: linux-pwm, kernel
Hi Uwe,
> From: Uwe Kleine-Konig, Sent: Thursday, October 24, 2019 4:14 PM
>
> When .apply is called with state->duty_cycle = 0 the duty_ns parameter
> to rcar_pwm_set_counter() is 0 which results in ph being 0 and
> rcar_pwm_set_counter() returning -EINVAL.
>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Thank you for the patch!
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Best regards,
Yoshihiro Shimoda
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2019-10-24 7:20 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2019-10-24 7:14 [PATCH 1/2] pwm: rcar: Drop useless call to pwm_get_state Uwe Kleine-König
2019-10-24 7:14 ` [PATCH 2/2] pwm: rcar: Document inability to set duty_cycle = 0 Uwe Kleine-König
2019-10-24 7:20 ` Yoshihiro Shimoda
2019-10-24 7:20 ` [PATCH 1/2] pwm: rcar: Drop useless call to pwm_get_state Yoshihiro Shimoda
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