drm/rockchip: add an common abstracted PSR driver

Hello Yakir Yang,

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

The patch 5182c1a556d7: "drm/rockchip: add an common abstracted PSR driver" from Jul 24, 2016, leads to the following Smatch complaint:

drivers/gpu/drm/rockchip/rockchip_drm_psr.c:228 rockchip_drm_psr_register()
warn: variable dereferenced before check 'encoder' (see line 224)

drivers/gpu/drm/rockchip/rockchip_drm_psr.c
223 {

   224		struct rockchip_drm_private *drm_drv = encoder->dev->dev_private;
                                                       ^^^^^^^^^

Dereference.

225 struct psr_drv *psr;
226 unsigned long flags;
227
228 if (!encoder || !psr_set)

                     ^^^^^^^

Check.

229 return -EINVAL;
230

regards,
dan carpenter