[bug report] firmware: scpi: add device power domain support using genpd

[Dan Carpenter <error27@gmail.com>]

Hello Sudeep Holla,

Commit 8bec4337ad40 ("firmware: scpi: add device power domain support
using genpd") from Jun 2, 2016 (linux-next), leads to the following
Smatch static checker warning:

	drivers/pmdomain/marvell/pxa1908-power-controller.c:231 pxa1908_pd_init()
	warn: passing positive error code '1' to 'dev_err_probe'

drivers/pmdomain/marvell/pxa1908-power-controller.c
    216 static int
    217 pxa1908_pd_init(struct pxa1908_pd_ctrl *ctrl, int id, struct device *dev)
    218 {
    219         struct pxa1908_pd *pd = &domains[id];
    220         int ret;
    221 
    222         ctrl->domains[id] = &pd->genpd;
    223 
    224         pd->ctrl = ctrl;
    225 
    226         /* Make sure the state of the hardware is synced with the domain table above. */
    227         if (pd->data.keep_on) {
    228                 ret = pd->genpd.power_on(&pd->genpd);
    229                 if (ret)
    230                         return dev_err_probe(dev, ret, "failed to power on domain '%s'\n",
--> 231                                              pd->genpd.name);
    232         } else {

The problem is that genpd.power_on() functions are supposed to return
0 on success or negative error codes.

drivers/pmdomain/arm/scpi_pm_domain.c
    34  static int scpi_pd_power(struct scpi_pm_domain *pd, bool power_on)
    35  {
    36          int ret;
    37          enum scpi_power_domain_state state;
    38  
    39          if (power_on)
    40                  state = SCPI_PD_STATE_ON;
    41          else
    42                  state = SCPI_PD_STATE_OFF;
    43  
    44          ret = pd->ops->device_set_power_state(pd->domain, state);
    45          if (ret)
    46                  return ret;
                        ^^^^^^^^^^^
Negatives.  Good.

    47  
    48          return !(state == pd->ops->device_get_power_state(pd->domain));
                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
But this returns 0/1.

    49  }
    50  
    51  static int scpi_pd_power_on(struct generic_pm_domain *domain)
    52  {
    53          struct scpi_pm_domain *pd = to_scpi_pd(domain);
    54  
    55          return scpi_pd_power(pd, true);
    56  }
    57  
    58  static int scpi_pd_power_off(struct generic_pm_domain *domain)
    59  {
    60          struct scpi_pm_domain *pd = to_scpi_pd(domain);
    61  
    62          return scpi_pd_power(pd, false);
    63  }

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regards,
dan carpenter