[bug report] drm/ingenic: Add support for the IPU

[Dan Carpenter]

On Mon, Jul 20, 2020 at 10:22:37AM +0300, dan.carpenter at oracle.com wrote:
> Hello Paul Cercueil,
> 
> The patch fc1acf317b01: "drm/ingenic: Add support for the IPU" from
> Jul 16, 2020, leads to the following static checker warning:
> 
> 	drivers/gpu/drm/ingenic/ingenic-drm-drv.c:232 ingenic_drm_crtc_atomic_check()
> 	error: potentially dereferencing uninitialized 'ipu_state'.
> 
> drivers/gpu/drm/ingenic/ingenic-drm-drv.c
>    197  static int ingenic_drm_crtc_atomic_check(struct drm_crtc *crtc,
>    198                                           struct drm_crtc_state *state)
>    199  {
>    200          struct ingenic_drm *priv = drm_crtc_get_priv(crtc);
>    201          struct drm_plane_state *f1_state, *f0_state, *ipu_state;
>    202          long rate;
>    203  
>    204          if (!drm_atomic_crtc_needs_modeset(state))
>    205                  return 0;
>    206  
>    207          if (state->mode.hdisplay > priv->soc_info->max_width ||
>    208              state->mode.vdisplay > priv->soc_info->max_height)
>    209                  return -EINVAL;
>    210  
>    211          rate = clk_round_rate(priv->pix_clk,
>    212                                state->adjusted_mode.clock * 1000);
>    213          if (rate < 0)
>    214                  return rate;
>    215  
>    216          if (priv->soc_info->has_osd) {
>    217                  f1_state = drm_atomic_get_plane_state(state->state, &priv->f1);
>    218                  f0_state = drm_atomic_get_plane_state(state->state, &priv->f0);

drivers/gpu/drm/ingenic/ingenic-drm-drv.c:224 ingenic_drm_crtc_atomic_check() error: 'f1_state' dereferencing possible ERR_PTR()
drivers/gpu/drm/ingenic/ingenic-drm-drv.c:224 ingenic_drm_crtc_atomic_check() error: 'ipu_state' dereferencing possible ERR_PTR()
drivers/gpu/drm/ingenic/ingenic-drm-drv.c:231 ingenic_drm_crtc_atomic_check() error: 'f1_state' dereferencing possible ERR_PTR()
drivers/gpu/drm/ingenic/ingenic-drm-drv.c:231 ingenic_drm_crtc_atomic_check() error: 'f0_state' dereferencing possible ERR_PTR()
drivers/gpu/drm/ingenic/ingenic-drm-drv.c:232 ingenic_drm_crtc_atomic_check() error: 'ipu_state' dereferencing possible ERR_PTR()

Also Smatch complains that these need error checking.

regards,
dan carpenter