* [PATCH 0/4] pwm: add power management on sysfs and switch to SPDX
@ 2019-05-29 7:47 Yoshihiro Shimoda
2019-05-29 7:47 ` [PATCH 1/4] pwm: Add power management descriptions Yoshihiro Shimoda
` (4 more replies)
0 siblings, 5 replies; 9+ messages in thread
From: Yoshihiro Shimoda @ 2019-05-29 7:47 UTC (permalink / raw)
To: thierry.reding; +Cc: linux-pwm, linux-renesas-soc, Yoshihiro Shimoda
This patch series is affected from the following email:
https://marc.info/?l=linux-renesas-soc&m=155896668906609&w=2
- The patch 1 adds descriptions into Documentation/pwm.txt.
- The patch 2 is not related to the topic though, switches to
SPDX identifier of sysfs.c.
- The patch 3 adds suspend/resume support into sysfs.c.
- The patch 4 removes suspend/resume support from pwm-rcar.c.
This is the first trial so that I didn't make patches for other
PWM drivers to remove suspend/resume support.
Yoshihiro Shimoda (4):
pwm: Add power management descriptions
pwm: sysfs: Switch to SPDX identifier
pwm: sysfs: Add suspend/resume support
pwm: rcar: Remove suspend/resume support
Documentation/pwm.txt | 7 +++++
drivers/pwm/pwm-rcar.c | 39 --------------------------
drivers/pwm/sysfs.c | 75 +++++++++++++++++++++++++++++++++++++++++++-------
3 files changed, 72 insertions(+), 49 deletions(-)
--
2.7.4
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH 1/4] pwm: Add power management descriptions
2019-05-29 7:47 [PATCH 0/4] pwm: add power management on sysfs and switch to SPDX Yoshihiro Shimoda
@ 2019-05-29 7:47 ` Yoshihiro Shimoda
2019-05-29 7:48 ` [PATCH 2/4] pwm: sysfs: Switch to SPDX identifier Yoshihiro Shimoda
` (3 subsequent siblings)
4 siblings, 0 replies; 9+ messages in thread
From: Yoshihiro Shimoda @ 2019-05-29 7:47 UTC (permalink / raw)
To: thierry.reding; +Cc: linux-pwm, linux-renesas-soc, Yoshihiro Shimoda
This patch adds power management descriptions that consumers should
implement it.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
---
Documentation/pwm.txt | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/Documentation/pwm.txt b/Documentation/pwm.txt
index 8fbf0aa..996e5ea 100644
--- a/Documentation/pwm.txt
+++ b/Documentation/pwm.txt
@@ -65,6 +65,10 @@ period). struct pwm_args contains 2 fields (period and polarity) and should
be used to set the initial PWM config (usually done in the probe function
of the PWM user). PWM arguments are retrieved with pwm_get_args().
+All consumers should really be reconfiguring the PWM upon resume as
+appropriate. This is the only way to ensure that everything is resumed in
+the proper order.
+
Using PWMs with the sysfs interface
-----------------------------------
@@ -141,6 +145,9 @@ The implementation of ->get_state() (a method used to retrieve initial PWM
state) is also encouraged for the same reason: letting the PWM user know
about the current PWM state would allow him to avoid glitches.
+Drivers should not implement any power management. In other words,
+consumers should implement it as described as the "Using PWMs" section.
+
Locking
-------
--
2.7.4
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH 2/4] pwm: sysfs: Switch to SPDX identifier
2019-05-29 7:47 [PATCH 0/4] pwm: add power management on sysfs and switch to SPDX Yoshihiro Shimoda
2019-05-29 7:47 ` [PATCH 1/4] pwm: Add power management descriptions Yoshihiro Shimoda
@ 2019-05-29 7:48 ` Yoshihiro Shimoda
2019-05-29 7:48 ` [PATCH 3/4] pwm: sysfs: Add suspend/resume support Yoshihiro Shimoda
` (2 subsequent siblings)
4 siblings, 0 replies; 9+ messages in thread
From: Yoshihiro Shimoda @ 2019-05-29 7:48 UTC (permalink / raw)
To: thierry.reding; +Cc: linux-pwm, linux-renesas-soc, Yoshihiro Shimoda
Adopt the SPDX license identifier headers to ease license compliance
management.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
---
drivers/pwm/sysfs.c | 11 +----------
1 file changed, 1 insertion(+), 10 deletions(-)
diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c
index 719f8fa..7eb4a13 100644
--- a/drivers/pwm/sysfs.c
+++ b/drivers/pwm/sysfs.c
@@ -1,19 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0+
/*
* A simple sysfs interface for the generic PWM framework
*
* Copyright (C) 2013 H Hartley Sweeten <hsweeten@visionengravers.com>
*
* Based on previous work by Lars Poeschel <poeschel@lemonage.de>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2, or (at your option)
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
*/
#include <linux/device.h>
--
2.7.4
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH 3/4] pwm: sysfs: Add suspend/resume support
2019-05-29 7:47 [PATCH 0/4] pwm: add power management on sysfs and switch to SPDX Yoshihiro Shimoda
2019-05-29 7:47 ` [PATCH 1/4] pwm: Add power management descriptions Yoshihiro Shimoda
2019-05-29 7:48 ` [PATCH 2/4] pwm: sysfs: Switch to SPDX identifier Yoshihiro Shimoda
@ 2019-05-29 7:48 ` Yoshihiro Shimoda
2019-05-29 13:38 ` Thierry Reding
2019-05-29 7:48 ` [PATCH 4/4] pwm: rcar: Remove " Yoshihiro Shimoda
2019-05-29 13:32 ` [PATCH 0/4] pwm: add power management on sysfs and switch to SPDX Thierry Reding
4 siblings, 1 reply; 9+ messages in thread
From: Yoshihiro Shimoda @ 2019-05-29 7:48 UTC (permalink / raw)
To: thierry.reding; +Cc: linux-pwm, linux-renesas-soc, Yoshihiro Shimoda
According to the Documentation/pwm.txt, all PWM consumers should have
power management. Since this sysfs interface is one of consumers so that
this patch adds suspend/resume support.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
---
drivers/pwm/sysfs.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 64 insertions(+)
diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c
index 7eb4a13..72dafdd 100644
--- a/drivers/pwm/sysfs.c
+++ b/drivers/pwm/sysfs.c
@@ -18,6 +18,7 @@ struct pwm_export {
struct device child;
struct pwm_device *pwm;
struct mutex lock;
+ bool enabled_in_suspend;
};
static struct pwm_export *child_to_pwm_export(struct device *child)
@@ -372,10 +373,73 @@ static struct attribute *pwm_chip_attrs[] = {
};
ATTRIBUTE_GROUPS(pwm_chip);
+static int pwm_class_suspend_resume(struct device *parent, bool suspend)
+{
+ struct pwm_chip *chip = dev_get_drvdata(parent);
+ unsigned int i;
+ int ret = 0;
+
+ for (i = 0; i < chip->npwm; i++) {
+ struct pwm_device *pwm = &chip->pwms[i];
+ struct device *child;
+ struct pwm_export *export;
+ struct pwm_state state;
+
+ if (!test_bit(PWMF_EXPORTED, &pwm->flags))
+ continue;
+
+ child = device_find_child(parent, pwm, pwm_unexport_match);
+ if (!child)
+ goto rollback;
+
+ export = child_to_pwm_export(child);
+ put_device(child); /* for device_find_child() */
+ if (!export)
+ goto rollback;
+
+ mutex_lock(&export->lock);
+ pwm_get_state(pwm, &state);
+ if (suspend) {
+ if (state.enabled)
+ export->enabled_in_suspend = true;
+ state.enabled = false;
+ } else if (export->enabled_in_suspend) {
+ state.enabled = true;
+ export->enabled_in_suspend = false;
+ }
+ ret = pwm_apply_state(pwm, &state);
+ mutex_unlock(&export->lock);
+ if (ret < 0)
+ goto rollback;
+ }
+
+ return ret;
+
+rollback:
+ /* roll back only when suspend */
+ if (suspend)
+ pwm_class_suspend_resume(parent, false);
+
+ return ret;
+}
+
+static int pwm_class_suspend(struct device *parent)
+{
+ return pwm_class_suspend_resume(parent, true);
+}
+
+static int pwm_class_resume(struct device *parent)
+{
+ return pwm_class_suspend_resume(parent, false);
+}
+
+static SIMPLE_DEV_PM_OPS(pwm_class_pm_ops, pwm_class_suspend, pwm_class_resume);
+
static struct class pwm_class = {
.name = "pwm",
.owner = THIS_MODULE,
.dev_groups = pwm_chip_groups,
+ .pm = &pwm_class_pm_ops,
};
static int pwmchip_sysfs_match(struct device *parent, const void *data)
--
2.7.4
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH 4/4] pwm: rcar: Remove suspend/resume support
2019-05-29 7:47 [PATCH 0/4] pwm: add power management on sysfs and switch to SPDX Yoshihiro Shimoda
` (2 preceding siblings ...)
2019-05-29 7:48 ` [PATCH 3/4] pwm: sysfs: Add suspend/resume support Yoshihiro Shimoda
@ 2019-05-29 7:48 ` Yoshihiro Shimoda
2019-05-29 13:38 ` Thierry Reding
2019-05-29 13:32 ` [PATCH 0/4] pwm: add power management on sysfs and switch to SPDX Thierry Reding
4 siblings, 1 reply; 9+ messages in thread
From: Yoshihiro Shimoda @ 2019-05-29 7:48 UTC (permalink / raw)
To: thierry.reding; +Cc: linux-pwm, linux-renesas-soc, Yoshihiro Shimoda
According to the Documentation/pwm.txt, all PWM consumers should
implement power management instead of the PWM driver. So, this
patch removes suspend/resume support.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
---
drivers/pwm/pwm-rcar.c | 39 ---------------------------------------
1 file changed, 39 deletions(-)
diff --git a/drivers/pwm/pwm-rcar.c b/drivers/pwm/pwm-rcar.c
index cfe7dd1..5b2b8ec 100644
--- a/drivers/pwm/pwm-rcar.c
+++ b/drivers/pwm/pwm-rcar.c
@@ -254,50 +254,11 @@ static const struct of_device_id rcar_pwm_of_table[] = {
};
MODULE_DEVICE_TABLE(of, rcar_pwm_of_table);
-#ifdef CONFIG_PM_SLEEP
-static struct pwm_device *rcar_pwm_dev_to_pwm_dev(struct device *dev)
-{
- struct rcar_pwm_chip *rcar_pwm = dev_get_drvdata(dev);
- struct pwm_chip *chip = &rcar_pwm->chip;
-
- return &chip->pwms[0];
-}
-
-static int rcar_pwm_suspend(struct device *dev)
-{
- struct pwm_device *pwm = rcar_pwm_dev_to_pwm_dev(dev);
-
- if (!test_bit(PWMF_REQUESTED, &pwm->flags))
- return 0;
-
- pm_runtime_put(dev);
-
- return 0;
-}
-
-static int rcar_pwm_resume(struct device *dev)
-{
- struct pwm_device *pwm = rcar_pwm_dev_to_pwm_dev(dev);
- struct pwm_state state;
-
- if (!test_bit(PWMF_REQUESTED, &pwm->flags))
- return 0;
-
- pm_runtime_get_sync(dev);
-
- pwm_get_state(pwm, &state);
-
- return rcar_pwm_apply(pwm->chip, pwm, &state);
-}
-#endif /* CONFIG_PM_SLEEP */
-static SIMPLE_DEV_PM_OPS(rcar_pwm_pm_ops, rcar_pwm_suspend, rcar_pwm_resume);
-
static struct platform_driver rcar_pwm_driver = {
.probe = rcar_pwm_probe,
.remove = rcar_pwm_remove,
.driver = {
.name = "pwm-rcar",
- .pm = &rcar_pwm_pm_ops,
.of_match_table = of_match_ptr(rcar_pwm_of_table),
}
};
--
2.7.4
^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH 0/4] pwm: add power management on sysfs and switch to SPDX
2019-05-29 7:47 [PATCH 0/4] pwm: add power management on sysfs and switch to SPDX Yoshihiro Shimoda
` (3 preceding siblings ...)
2019-05-29 7:48 ` [PATCH 4/4] pwm: rcar: Remove " Yoshihiro Shimoda
@ 2019-05-29 13:32 ` Thierry Reding
4 siblings, 0 replies; 9+ messages in thread
From: Thierry Reding @ 2019-05-29 13:32 UTC (permalink / raw)
To: Yoshihiro Shimoda; +Cc: linux-pwm, linux-renesas-soc
[-- Attachment #1: Type: text/plain, Size: 1203 bytes --]
On Wed, May 29, 2019 at 04:47:58PM +0900, Yoshihiro Shimoda wrote:
> This patch series is affected from the following email:
> https://marc.info/?l=linux-renesas-soc&m=155896668906609&w=2
>
> - The patch 1 adds descriptions into Documentation/pwm.txt.
> - The patch 2 is not related to the topic though, switches to
> SPDX identifier of sysfs.c.
> - The patch 3 adds suspend/resume support into sysfs.c.
> - The patch 4 removes suspend/resume support from pwm-rcar.c.
>
> This is the first trial so that I didn't make patches for other
> PWM drivers to remove suspend/resume support.
Thanks for doing this. It's looking already pretty good. Just a couple
of minor comments in the individual patches.
Thierry
>
> Yoshihiro Shimoda (4):
> pwm: Add power management descriptions
> pwm: sysfs: Switch to SPDX identifier
> pwm: sysfs: Add suspend/resume support
> pwm: rcar: Remove suspend/resume support
>
> Documentation/pwm.txt | 7 +++++
> drivers/pwm/pwm-rcar.c | 39 --------------------------
> drivers/pwm/sysfs.c | 75 +++++++++++++++++++++++++++++++++++++++++++-------
> 3 files changed, 72 insertions(+), 49 deletions(-)
>
> --
> 2.7.4
>
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^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH 3/4] pwm: sysfs: Add suspend/resume support
2019-05-29 7:48 ` [PATCH 3/4] pwm: sysfs: Add suspend/resume support Yoshihiro Shimoda
@ 2019-05-29 13:38 ` Thierry Reding
2019-05-30 10:12 ` Yoshihiro Shimoda
0 siblings, 1 reply; 9+ messages in thread
From: Thierry Reding @ 2019-05-29 13:38 UTC (permalink / raw)
To: Yoshihiro Shimoda; +Cc: linux-pwm, linux-renesas-soc
[-- Attachment #1: Type: text/plain, Size: 4006 bytes --]
On Wed, May 29, 2019 at 04:48:01PM +0900, Yoshihiro Shimoda wrote:
> According to the Documentation/pwm.txt, all PWM consumers should have
> power management. Since this sysfs interface is one of consumers so that
> this patch adds suspend/resume support.
>
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> ---
> drivers/pwm/sysfs.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 64 insertions(+)
>
> diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c
> index 7eb4a13..72dafdd 100644
> --- a/drivers/pwm/sysfs.c
> +++ b/drivers/pwm/sysfs.c
> @@ -18,6 +18,7 @@ struct pwm_export {
> struct device child;
> struct pwm_device *pwm;
> struct mutex lock;
> + bool enabled_in_suspend;
How about if we save the complete state here? Something like:
struct pwm_state suspend;
Or similar? Then we can just pwm_get_state() into that and then disable
the PWM like you do.
> };
>
> static struct pwm_export *child_to_pwm_export(struct device *child)
> @@ -372,10 +373,73 @@ static struct attribute *pwm_chip_attrs[] = {
> };
> ATTRIBUTE_GROUPS(pwm_chip);
>
> +static int pwm_class_suspend_resume(struct device *parent, bool suspend)
I would prefer if these were separate functions. I think the kind of
conditionals that you have below isn't worth the few lines that you may
save by fusing suspend/resume into one function.
Also, if you store struct pwm_state suspend during suspend, then both
implementations will end up being fairly different, so reusing the code
isn't going to be much of an advantage.
> +{
> + struct pwm_chip *chip = dev_get_drvdata(parent);
> + unsigned int i;
> + int ret = 0;
> +
> + for (i = 0; i < chip->npwm; i++) {
> + struct pwm_device *pwm = &chip->pwms[i];
> + struct device *child;
> + struct pwm_export *export;
> + struct pwm_state state;
> +
> + if (!test_bit(PWMF_EXPORTED, &pwm->flags))
> + continue;
> +
> + child = device_find_child(parent, pwm, pwm_unexport_match);
> + if (!child)
> + goto rollback;
> +
> + export = child_to_pwm_export(child);
> + put_device(child); /* for device_find_child() */
> + if (!export)
> + goto rollback;
Con this even happen? I have a hard time seeing how.
> +
> + mutex_lock(&export->lock);
> + pwm_get_state(pwm, &state);
All of the above is shared code, so perhaps it'd be worth putting that
into a separate helper function to achieve the code reuse that you
otherwise get from sharing the function.
> + if (suspend) {
> + if (state.enabled)
> + export->enabled_in_suspend = true;
> + state.enabled = false;
> + } else if (export->enabled_in_suspend) {
> + state.enabled = true;
> + export->enabled_in_suspend = false;
> + }
This in particular is what I mean. I think the two levels of
conditionals here make this more complicated to understand than
necessary.
> + ret = pwm_apply_state(pwm, &state);
> + mutex_unlock(&export->lock);
> + if (ret < 0)
> + goto rollback;
> + }
> +
> + return ret;
> +
> +rollback:
> + /* roll back only when suspend */
> + if (suspend)
> + pwm_class_suspend_resume(parent, false);
And then there's stuff like this where you need to explain what's going
on just to save a couple of lines of code.
Other than that, looks really nice.
Thierry
> +
> + return ret;
> +}
> +
> +static int pwm_class_suspend(struct device *parent)
> +{
> + return pwm_class_suspend_resume(parent, true);
> +}
> +
> +static int pwm_class_resume(struct device *parent)
> +{
> + return pwm_class_suspend_resume(parent, false);
> +}
> +
> +static SIMPLE_DEV_PM_OPS(pwm_class_pm_ops, pwm_class_suspend, pwm_class_resume);
> +
> static struct class pwm_class = {
> .name = "pwm",
> .owner = THIS_MODULE,
> .dev_groups = pwm_chip_groups,
> + .pm = &pwm_class_pm_ops,
> };
>
> static int pwmchip_sysfs_match(struct device *parent, const void *data)
> --
> 2.7.4
>
[-- Attachment #2: signature.asc --]
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^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH 4/4] pwm: rcar: Remove suspend/resume support
2019-05-29 7:48 ` [PATCH 4/4] pwm: rcar: Remove " Yoshihiro Shimoda
@ 2019-05-29 13:38 ` Thierry Reding
0 siblings, 0 replies; 9+ messages in thread
From: Thierry Reding @ 2019-05-29 13:38 UTC (permalink / raw)
To: Yoshihiro Shimoda; +Cc: linux-pwm, linux-renesas-soc
[-- Attachment #1: Type: text/plain, Size: 478 bytes --]
On Wed, May 29, 2019 at 04:48:02PM +0900, Yoshihiro Shimoda wrote:
> According to the Documentation/pwm.txt, all PWM consumers should
> implement power management instead of the PWM driver. So, this
> patch removes suspend/resume support.
>
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> ---
> drivers/pwm/pwm-rcar.c | 39 ---------------------------------------
> 1 file changed, 39 deletions(-)
Yes, I like that very much. =)
Thierry
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]
^ permalink raw reply [flat|nested] 9+ messages in thread
* RE: [PATCH 3/4] pwm: sysfs: Add suspend/resume support
2019-05-29 13:38 ` Thierry Reding
@ 2019-05-30 10:12 ` Yoshihiro Shimoda
0 siblings, 0 replies; 9+ messages in thread
From: Yoshihiro Shimoda @ 2019-05-30 10:12 UTC (permalink / raw)
To: Thierry Reding; +Cc: linux-pwm, linux-renesas-soc
Hi Thierry,
> From: Thierry Reding, Sent: Wednesday, May 29, 2019 10:38 PM
>
> On Wed, May 29, 2019 at 04:48:01PM +0900, Yoshihiro Shimoda wrote:
> > According to the Documentation/pwm.txt, all PWM consumers should have
> > power management. Since this sysfs interface is one of consumers so that
> > this patch adds suspend/resume support.
> >
> > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> > ---
> > drivers/pwm/sysfs.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 64 insertions(+)
> >
> > diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c
> > index 7eb4a13..72dafdd 100644
> > --- a/drivers/pwm/sysfs.c
> > +++ b/drivers/pwm/sysfs.c
> > @@ -18,6 +18,7 @@ struct pwm_export {
> > struct device child;
> > struct pwm_device *pwm;
> > struct mutex lock;
> > + bool enabled_in_suspend;
>
> How about if we save the complete state here? Something like:
>
> struct pwm_state suspend;
>
> Or similar? Then we can just pwm_get_state() into that and then disable
> the PWM like you do.
I got it. I'll fix it on v2.
> > };
> >
> > static struct pwm_export *child_to_pwm_export(struct device *child)
> > @@ -372,10 +373,73 @@ static struct attribute *pwm_chip_attrs[] = {
> > };
> > ATTRIBUTE_GROUPS(pwm_chip);
> >
> > +static int pwm_class_suspend_resume(struct device *parent, bool suspend)
>
> I would prefer if these were separate functions. I think the kind of
> conditionals that you have below isn't worth the few lines that you may
> save by fusing suspend/resume into one function.
>
> Also, if you store struct pwm_state suspend during suspend, then both
> implementations will end up being fairly different, so reusing the code
> isn't going to be much of an advantage.
I got it. As you said, separate functions are better for the code readability.
> > +{
> > + struct pwm_chip *chip = dev_get_drvdata(parent);
> > + unsigned int i;
> > + int ret = 0;
> > +
> > + for (i = 0; i < chip->npwm; i++) {
> > + struct pwm_device *pwm = &chip->pwms[i];
> > + struct device *child;
> > + struct pwm_export *export;
> > + struct pwm_state state;
> > +
> > + if (!test_bit(PWMF_EXPORTED, &pwm->flags))
> > + continue;
> > +
> > + child = device_find_child(parent, pwm, pwm_unexport_match);
> > + if (!child)
> > + goto rollback;
> > +
> > + export = child_to_pwm_export(child);
> > + put_device(child); /* for device_find_child() */
> > + if (!export)
> > + goto rollback;
>
> Con this even happen? I have a hard time seeing how.
Oops! This condition is unnecessary. I'll remove it.
> > +
> > + mutex_lock(&export->lock);
> > + pwm_get_state(pwm, &state);
>
> All of the above is shared code, so perhaps it'd be worth putting that
> into a separate helper function to achieve the code reuse that you
> otherwise get from sharing the function.
I got it. I'll make such a helper function on v2.
> > + if (suspend) {
> > + if (state.enabled)
> > + export->enabled_in_suspend = true;
> > + state.enabled = false;
> > + } else if (export->enabled_in_suspend) {
> > + state.enabled = true;
> > + export->enabled_in_suspend = false;
> > + }
>
> This in particular is what I mean. I think the two levels of
> conditionals here make this more complicated to understand than
> necessary.
I think so.
> > + ret = pwm_apply_state(pwm, &state);
> > + mutex_unlock(&export->lock);
> > + if (ret < 0)
> > + goto rollback;
> > + }
> > +
> > + return ret;
> > +
> > +rollback:
> > + /* roll back only when suspend */
> > + if (suspend)
> > + pwm_class_suspend_resume(parent, false);
>
> And then there's stuff like this where you need to explain what's going
> on just to save a couple of lines of code.
I'll add a comment on v2.
> Other than that, looks really nice.
Thank you for your review!
Best regards,
Yoshihiro Shimoda
> Thierry
>
> > +
> > + return ret;
> > +}
> > +
> > +static int pwm_class_suspend(struct device *parent)
> > +{
> > + return pwm_class_suspend_resume(parent, true);
> > +}
> > +
> > +static int pwm_class_resume(struct device *parent)
> > +{
> > + return pwm_class_suspend_resume(parent, false);
> > +}
> > +
> > +static SIMPLE_DEV_PM_OPS(pwm_class_pm_ops, pwm_class_suspend, pwm_class_resume);
> > +
> > static struct class pwm_class = {
> > .name = "pwm",
> > .owner = THIS_MODULE,
> > .dev_groups = pwm_chip_groups,
> > + .pm = &pwm_class_pm_ops,
> > };
> >
> > static int pwmchip_sysfs_match(struct device *parent, const void *data)
> > --
> > 2.7.4
> >
^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2019-05-30 10:13 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-05-29 7:47 [PATCH 0/4] pwm: add power management on sysfs and switch to SPDX Yoshihiro Shimoda
2019-05-29 7:47 ` [PATCH 1/4] pwm: Add power management descriptions Yoshihiro Shimoda
2019-05-29 7:48 ` [PATCH 2/4] pwm: sysfs: Switch to SPDX identifier Yoshihiro Shimoda
2019-05-29 7:48 ` [PATCH 3/4] pwm: sysfs: Add suspend/resume support Yoshihiro Shimoda
2019-05-29 13:38 ` Thierry Reding
2019-05-30 10:12 ` Yoshihiro Shimoda
2019-05-29 7:48 ` [PATCH 4/4] pwm: rcar: Remove " Yoshihiro Shimoda
2019-05-29 13:38 ` Thierry Reding
2019-05-29 13:32 ` [PATCH 0/4] pwm: add power management on sysfs and switch to SPDX Thierry Reding
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