Re: [bug report] hwmon: Add hardware monitoring driver for Moortec MR75203 PVT controller

[Guenter Roeck <linux@roeck-us.net>]

On Tue, Oct 13, 2020 at 05:08:58PM +0300, Dan Carpenter wrote:
> Hello Rahul Tanwar,
> 
> The patch 9d823351a337: "hwmon: Add hardware monitoring driver for
> Moortec MR75203 PVT controller" from Oct 5, 2020, leads to the
> following static checker warning:
> 
> 	drivers/hwmon/mr75203.c:479 pvt_clk_enable()
> 	warn: 'pvt->clk' not released on lines: 479.
> 
> drivers/hwmon/mr75203.c
>    471  static int pvt_clk_enable(struct device *dev, struct pvt_device *pvt)
>    472  {
>    473          int ret;
>    474  
>    475          ret = clk_prepare_enable(pvt->clk);
>    476          if (ret)
>    477                  return ret;
>    478  
>    479          return devm_add_action_or_reset(dev, pvt_clk_disable, pvt);
> 
> Do we have to disable the clock if devm_add_action_or_reset() fails?
> This is sort of a new Smatch check so I'm not entirely sure of the rules
> mysql.

devm_add_action_or_reset calls the callback function (here:
pvt_clk_disable) if there is an error, and the callback function
releases the clock. This is a workaround for the missing
devm_clk_prepare_enable(); you'll find it all over the kernel
by now.

Guenter

> 
>    480  }
> 
> regards,
> dan carpenter