[PATCH] phy: core: Allow phy_pm_runtime_xxx API calls with NULL phy

[PATCH] phy: core: Allow phy_pm_runtime_xxx API calls with NULL phy

[Manu Gautam]

phy_init() and phy_exit() calls, and phy_power_on() and
phy_power_off() already accept NULL as valid PHY refernece
and act as NOP. Extend same concept to phy runtime_pm APIs
to keep drivers (e.g. dwc3) code simple while dealing with
optional PHYs.

Signed-off-by: Manu Gautam <mgautam@codeaurora.org>
---
 drivers/phy/phy-core.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
index 09ac8af..48b9615 100644
--- a/drivers/phy/phy-core.c
+++ b/drivers/phy/phy-core.c
@@ -153,6 +153,9 @@ int phy_pm_runtime_get(struct phy *phy)
 {
 	int ret;
 
+	if (!phy)
+		return 0;
+
 	if (!pm_runtime_enabled(&phy->dev))
 		return -ENOTSUPP;
 
@@ -168,6 +171,9 @@ int phy_pm_runtime_get_sync(struct phy *phy)
 {
 	int ret;
 
+	if (!phy)
+		return 0;
+
 	if (!pm_runtime_enabled(&phy->dev))
 		return -ENOTSUPP;
 
@@ -181,6 +187,9 @@ int phy_pm_runtime_get_sync(struct phy *phy)
 
 int phy_pm_runtime_put(struct phy *phy)
 {
+	if (!phy)
+		return 0;
+
 	if (!pm_runtime_enabled(&phy->dev))
 		return -ENOTSUPP;
 
@@ -190,6 +199,9 @@ int phy_pm_runtime_put(struct phy *phy)
 
 int phy_pm_runtime_put_sync(struct phy *phy)
 {
+	if (!phy)
+		return 0;
+
 	if (!pm_runtime_enabled(&phy->dev))
 		return -ENOTSUPP;
 
@@ -199,6 +211,9 @@ int phy_pm_runtime_put_sync(struct phy *phy)
 
 void phy_pm_runtime_allow(struct phy *phy)
 {
+	if (!phy)
+		return 0;
+
 	if (!pm_runtime_enabled(&phy->dev))
 		return;
 
@@ -208,6 +223,9 @@ void phy_pm_runtime_allow(struct phy *phy)
 
 void phy_pm_runtime_forbid(struct phy *phy)
 {
+	if (!phy)
+		return 0;
+
 	if (!pm_runtime_enabled(&phy->dev))
 		return;
 
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH] phy: core: Allow phy_pm_runtime_xxx API calls with NULL phy

[kbuild test robot]

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Hi Manu,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on v4.16-rc4]
[also build test WARNING on next-20180316]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Manu-Gautam/phy-core-Allow-phy_pm_runtime_xxx-API-calls-with-NULL-phy/20180317-114302
config: x86_64-randconfig-x002-201810 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All warnings (new ones prefixed by >>):

   drivers/phy/phy-core.c: In function 'phy_pm_runtime_allow':
>> drivers/phy/phy-core.c:215:10: warning: 'return' with a value, in function returning void
      return 0;
             ^
   drivers/phy/phy-core.c:212:6: note: declared here
    void phy_pm_runtime_allow(struct phy *phy)
         ^~~~~~~~~~~~~~~~~~~~
   drivers/phy/phy-core.c: In function 'phy_pm_runtime_forbid':
   drivers/phy/phy-core.c:227:10: warning: 'return' with a value, in function returning void
      return 0;
             ^
   drivers/phy/phy-core.c:224:6: note: declared here
    void phy_pm_runtime_forbid(struct phy *phy)
         ^~~~~~~~~~~~~~~~~~~~~

vim +/return +215 drivers/phy/phy-core.c

   211	
   212	void phy_pm_runtime_allow(struct phy *phy)
   213	{
   214		if (!phy)
 > 215			return 0;
   216	
   217		if (!pm_runtime_enabled(&phy->dev))
   218			return;
   219	
   220		pm_runtime_allow(&phy->dev);
   221	}
   222	EXPORT_SYMBOL_GPL(phy_pm_runtime_allow);
   223	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

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Re: [PATCH] phy: core: Allow phy_pm_runtime_xxx API calls with NULL phy

[Vivek Gautam]

On 2018-03-16 14:40, Manu Gautam wrote:
> phy_init() and phy_exit() calls, and phy_power_on() and
> phy_power_off() already accept NULL as valid PHY refernece
> and act as NOP. Extend same concept to phy runtime_pm APIs
> to keep drivers (e.g. dwc3) code simple while dealing with
> optional PHYs.
> 
> Signed-off-by: Manu Gautam <mgautam@codeaurora.org>
> ---
>  drivers/phy/phy-core.c | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
> index 09ac8af..48b9615 100644
> --- a/drivers/phy/phy-core.c
> +++ b/drivers/phy/phy-core.c
> @@ -153,6 +153,9 @@ int phy_pm_runtime_get(struct phy *phy)
>  {
>  	int ret;
> 
> +	if (!phy)
> +		return 0;
> +
>  	if (!pm_runtime_enabled(&phy->dev))

Were we already trying to dereference a NULL here?
That shouldn't be good i guess.
Kishon, do we not expect phys to be NULL here?

<snip>

regards
Vivek