openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

mbp_nvidia_bl: check that the backlight control functions 

The SMI-based backlight control functionality may fail to work if the
system is running under EFI rather than BIOS.  Check that the hardware
responds as expected, and exit if it doesn't.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Acked-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Cc: Mourad De Clerck <mourad@aquazul.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Matthew Garrett 2011-03-22 16:30:27 -07:00 committed by Linus Torvalds
parent 23a9847f0d
commit 99fd28e194
1 changed files with 13 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
drivers/video/backlight/mbp_nvidia_bl.c
View File

@ -143,6 +143,7 @@ static int __devinit mb_bl_add(struct acpi_device *dev)
{
struct backlight_properties props;
struct pci_dev *host;
int intensity;
host = pci_get_bus_and_slot(0, 0);
@ -163,6 +164,18 @@ static int __devinit mb_bl_add(struct acpi_device *dev)
return -ENODEV;
}
/* Check that the hardware responds - this may not work under EFI */
intensity = hw_data->backlight_ops.get_brightness(NULL);
if (!intensity) {
hw_data->set_brightness(1);
if (!hw_data->backlight_ops.get_brightness(NULL))
return -ENODEV;
hw_data->set_brightness(0);
}
if (!request_region(hw_data->iostart, hw_data->iolen,
"Macbook backlight"))
return -ENXIO;