[PATCH] i2c: cadence: Fix PM device usage count

[PATCH] i2c: cadence: Fix PM device usage count

[Tobias Jordan]

pm_runtime_get_sync() increases the device's usage count even when
reporting an error, so add a call to pm_runtime_put_noidle() in the
error branch.

Fixes: 7fa32329ca03 ("i2c: cadence: Move to sensible power management")
Signed-off-by: Tobias Jordan <Tobias.Jordan@elektrobit.com>
---
This is one of a number of patches for problems found using coccinelle
scripting in the SIL2LinuxMP project. The patch has been compile-tested;
it's based on linux-next-20180223.

For a discussion of the corresponding issue, see
https://marc.info/?l=linux-pm&m=151904483924999&w=2

 drivers/i2c/busses/i2c-cadence.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c
index b13605718291..898faa7fbac5 100644
--- a/drivers/i2c/busses/i2c-cadence.c
+++ b/drivers/i2c/busses/i2c-cadence.c
@@ -574,8 +574,10 @@ static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 	bool hold_quirk;
 
 	ret = pm_runtime_get_sync(id->dev);
-	if (ret < 0)
+	if (ret < 0) {
+		pm_runtime_put_noidle(id->dev);
 		return ret;
+	}
 	/* Check if the bus is free */
 	if (cdns_i2c_readreg(CDNS_I2C_SR_OFFSET) & CDNS_I2C_SR_BA) {
 		ret = -EAGAIN;
-- 
2.11.0

Re: [SIL2review] [PATCH] i2c: cadence: Fix PM device usage count

[Nicholas Mc Guire]

On Sat, Feb 24, 2018 at 11:42:38PM +0100, Tobias Jordan wrote:
> pm_runtime_get_sync() increases the device's usage count even when
> reporting an error, so add a call to pm_runtime_put_noidle() in the
> error branch.
> 
> Fixes: 7fa32329ca03 ("i2c: cadence: Move to sensible power management")
> Signed-off-by: Tobias Jordan <Tobias.Jordan@elektrobit.com>
> ---
> This is one of a number of patches for problems found using coccinelle
> scripting in the SIL2LinuxMP project. The patch has been compile-tested;
> it's based on linux-next-20180223.
> 
> For a discussion of the corresponding issue, see
> https://marc.info/?l=linux-pm&m=151904483924999&w=2

just wondering if that should not be above the --- as:

Link: https://marc.info/?l=linux-pm&m=151904483924999&w=2

notably as the discussion about why not to fix it in __pm_runtime_resume
would seem reasonable to carry into the mainline logs.

thx!
hforat

> 
>  drivers/i2c/busses/i2c-cadence.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c
> index b13605718291..898faa7fbac5 100644
> --- a/drivers/i2c/busses/i2c-cadence.c
> +++ b/drivers/i2c/busses/i2c-cadence.c
> @@ -574,8 +574,10 @@ static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
>  	bool hold_quirk;
>  
>  	ret = pm_runtime_get_sync(id->dev);
> -	if (ret < 0)
> +	if (ret < 0) {
> +		pm_runtime_put_noidle(id->dev);
>  		return ret;
> +	}
>  	/* Check if the bus is free */
>  	if (cdns_i2c_readreg(CDNS_I2C_SR_OFFSET) & CDNS_I2C_SR_BA) {
>  		ret = -EAGAIN;
> -- 
> 2.11.0
> 
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