[bug report] drm/panfrost: Enable devfreq to work without regulator

[Dan Carpenter]

Hello Steven Price,

This is a semi-automatic email about new static checker warnings.

The patch e21dd290881b: "drm/panfrost: Enable devfreq to work without 
regulator" from Aug 16, 2019, leads to the following Smatch complaint:

    drivers/gpu/drm/panfrost/panfrost_devfreq.c:56 panfrost_devfreq_target()
    error: we previously assumed 'pfdev->regulator' could be null (see line 42)

drivers/gpu/drm/panfrost/panfrost_devfreq.c
    41		 */
    42		if (old_clk_rate < target_rate && pfdev->regulator) {
                                                  ^^^^^^^^^^^^^^^^
We added some new checks.

    43			err = regulator_set_voltage(pfdev->regulator, target_volt,
    44						    target_volt);
    45			if (err) {
    46				dev_err(dev, "Cannot set voltage %lu uV\n",
    47					target_volt);
    48				return err;
    49			}
    50		}
    51	
    52		err = clk_set_rate(pfdev->clock, target_rate);
    53		if (err) {
    54			dev_err(dev, "Cannot set frequency %lu (%d)\n", target_rate,
    55				err);
    56			regulator_set_voltage(pfdev->regulator, pfdev->devfreq.cur_volt,
                                              ^^^^^^^^^^^^^^^^
But here it isn't checked.

    57					      pfdev->devfreq.cur_volt);
    58			return err;

regards,
dan carpenter