From 1a468ba10c3bdbc25ef7aa7fecda20ee27007bdf Mon Sep 17 00:00:00 2001 From: Mario Schwalbe Date: Sun, 11 Jan 2009 00:19:31 +0000 Subject: [PATCH] backlight: mbp_nvidia_bl - Add a debug switch This patch adds a debug switch to enable (little) diagnostic output, to help to trace down the remaining problems. Signed-off-by: Mario Schwalbe Signed-off-by: Andrew Morton Signed-off-by: Richard Purdie --- drivers/video/backlight/mbp_nvidia_bl.c | 33 +++++++++++++++++++++++-- 1 file changed, 31 insertions(+), 2 deletions(-) diff --git a/drivers/video/backlight/mbp_nvidia_bl.c b/drivers/video/backlight/mbp_nvidia_bl.c index ce09b83244ac..3bb4c0a50c62 100644 --- a/drivers/video/backlight/mbp_nvidia_bl.c +++ b/drivers/video/backlight/mbp_nvidia_bl.c @@ -36,6 +36,11 @@ struct dmi_match_data { struct backlight_ops backlight_ops; }; +/* Module parameters. */ +static int debug; +module_param_named(debug, debug, int, 0644); +MODULE_PARM_DESC(debug, "Set to one to enable debugging messages."); + /* * Implementation for MacBooks with Intel chipset. */ @@ -43,6 +48,10 @@ static int intel_chipset_send_intensity(struct backlight_device *bd) { int intensity = bd->props.brightness; + if (debug) + printk(KERN_DEBUG "mbp_nvidia_bl: setting brightness to %d\n", + intensity); + outb(0x04 | (intensity << 4), 0xb3); outb(0xbf, 0xb2); return 0; @@ -50,9 +59,17 @@ static int intel_chipset_send_intensity(struct backlight_device *bd) static int intel_chipset_get_intensity(struct backlight_device *bd) { + int intensity; + outb(0x03, 0xb3); outb(0xbf, 0xb2); - return inb(0xb3) >> 4; + intensity = inb(0xb3) >> 4; + + if (debug) + printk(KERN_DEBUG "mbp_nvidia_bl: read brightness of %d\n", + intensity); + + return intensity; } static const struct dmi_match_data intel_chipset_data = { @@ -72,6 +89,10 @@ static int nvidia_chipset_send_intensity(struct backlight_device *bd) { int intensity = bd->props.brightness; + if (debug) + printk(KERN_DEBUG "mbp_nvidia_bl: setting brightness to %d\n", + intensity); + outb(0x04 | (intensity << 4), 0x52f); outb(0xbf, 0x52e); return 0; @@ -79,9 +100,17 @@ static int nvidia_chipset_send_intensity(struct backlight_device *bd) static int nvidia_chipset_get_intensity(struct backlight_device *bd) { + int intensity; + outb(0x03, 0x52f); outb(0xbf, 0x52e); - return inb(0x52f) >> 4; + intensity = inb(0x52f) >> 4; + + if (debug) + printk(KERN_DEBUG "mbp_nvidia_bl: read brightness of %d\n", + intensity); + + return intensity; } static const struct dmi_match_data nvidia_chipset_data = {