From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Date: Wed, 01 Feb 2012 09:42:54 +0000 Subject: re: backlight: Add pcf50633 backlight driver Message-Id: <20120201094254.GA24044@elgon.mountain> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-fbdev@vger.kernel.org Hello Lars-Peter Clausen, This is a semi-automatic email about new static checker warnings. The patch 2ddfd12f3584: "backlight: Add pcf50633 backlight driver" from May 12, 2010, leads to the following Smatch complaint: drivers/video/backlight/pcf50633-backlight.c +136 pcf50633_bl_probe() error: we previously assumed 'pdata' could be null (see line 118) drivers/video/backlight/pcf50633-backlight.c 117 118 if (pdata) { ^^^^^ check. 119 bl_props.brightness = pdata->default_brightness; 120 pcf_bl->brightness_limit = pdata->default_brightness_limit; 121 } else { 122 bl_props.brightness = 0x3f; 123 pcf_bl->brightness_limit = 0x3f; 124 } 125 126 pcf_bl->pcf = dev_to_pcf50633(pdev->dev.parent); 127 128 pcf_bl->bl = backlight_device_register(pdev->name, &pdev->dev, pcf_bl, 129 &pcf50633_bl_ops, &bl_props); 130 131 if (IS_ERR(pcf_bl->bl)) 132 return PTR_ERR(pcf_bl->bl); 133 134 platform_set_drvdata(pdev, pcf_bl); 135 136 pcf50633_reg_write(pcf_bl->pcf, PCF50633_REG_LEDDIM, pdata->ramp_time); ^^^^^^^^^^^^^^^^ dereference with checking. 137 138 /* Should be different from bl_props.brightness, so we do not exit regards, dan carpenter