re: drm/i2c: tda998x: use irq for connection status and EDID read

[Dan Carpenter <dan.carpenter@oracle.com>]

Hello Jean-Francois Moine,

The patch 12473b7d8e60: "drm/i2c: tda998x: use irq for connection
status and EDID read" from Jan 25, 2014, leads to the following
static checker warning:

	drivers/gpu/drm/i2c/tda998x_drv.c:1199 tda998x_encoder_destroy()
	warn: variable dereferenced before check 'priv->cec' (see line 1194)

drivers/gpu/drm/i2c/tda998x_drv.c
  1188  static void
  1189  tda998x_encoder_destroy(struct drm_encoder *encoder)
  1190  {
  1191          struct tda998x_priv *priv = to_tda998x_priv(encoder);
  1192  
  1193          /* disable all IRQs and free the IRQ handler */
  1194          cec_write(priv, REG_CEC_RXSHPDINTENA, 0);
                ^^^^^^^^^^^^^^
We dereference priv->cec inside the call to cec_write().

  1195          reg_clear(priv, REG_INT_FLAGS_2, INT_FLAGS_2_EDID_BLK_RD);
  1196          if (priv->hdmi->irq)
  1197                  free_irq(priv->hdmi->irq, priv);
  1198  
  1199          if (priv->cec)
                    ^^^^^^^^^
But later in the function we assume that ->cec can be NULL.

  1200                  i2c_unregister_device(priv->cec);
  1201          drm_i2c_encoder_destroy(encoder);
  1202          kfree(priv);
  1203  }

regards,
dan carpenter