ACPI: Skip the first two elements in the _BCL package (0a3db1ce) · Commits · 戴 / test

According to the Spec the first two elements in the _BCL package won't be regarded as the available brightness level. The first is the brightness when full power is connected to the box(It means that the AC adapter is plugged). The second is the brightness level when the box is on battery. If the first two elements are still used while finding the next brightness level, it will fall back to the lowest level when keeping on pressing hotkey. (On some boxes the brightness will be changed twice when hotkey is pressed once. One is in the ACPI video driver. The other is changed by sys I/F. In the ACPI video driver the first two elements will be used while changing the brightness. But the first two elements is skipped while using sys I/F. In such case there exists the inconsistency). So he first two elements had better be skipped while showing the available brightness or finding the next brightness level. http://bugzilla.kernel.org/show_bug.cgi?id=12450 Signed-off-by:

Zhao Yakui <yakui.zhao@intel.com> Signed-off-by:

Len Brown <len.brown@intel.com>

drivers/acpi/video.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -1020,7 +1020,7 @@ acpi_video_device_brightness_seq_show(struct seq_file seq, void offset)
		}

		seq_printf(seq, "levels: ");
		for (i = 0; i < dev->brightness->count; i++)
		for (i = 2; i < dev->brightness->count; i++)
		seq_printf(seq, " %d", dev->brightness->levels[i]);
		seq_printf(seq, "\ncurrent: %d\n", dev->brightness->curr);

		@@ -1059,7 +1059,7 @@ acpi_video_device_write_brightness(struct file *file,
		return -EFAULT;

		/* validate through the list of available levels */
		for (i = 0; i < dev->brightness->count; i++)
		for (i = 2; i < dev->brightness->count; i++)
		if (level == dev->brightness->levels[i]) {
		if (ACPI_SUCCESS
		(acpi_video_device_lcd_set_level(dev, level)))
		@@ -1712,7 +1712,7 @@ acpi_video_get_next_level(struct acpi_video_device *device,
		max = max_below = 0;
		min = min_above = 255;
		/* Find closest level to level_current */
		for (i = 0; i < device->brightness->count; i++) {
		for (i = 2; i < device->brightness->count; i++) {
		l = device->brightness->levels[i];
		if (abs(l - level_current) < abs(delta)) {
		delta = l - level_current;
		@@ -1722,7 +1722,7 @@ acpi_video_get_next_level(struct acpi_video_device *device,
		}
		/* Ajust level_current to closest available level */
		level_current += delta;
		for (i = 0; i < device->brightness->count; i++) {
		for (i = 2; i < device->brightness->count; i++) {
		l = device->brightness->levels[i];
		if (l < min)
		min = l;

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