diff options
Diffstat (limited to 'drivers/acpi/video.c')
| -rw-r--r-- | drivers/acpi/video.c | 40 |
1 files changed, 39 insertions, 1 deletions
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c index 9730ec167590..ae427100a1ef 100644 --- a/drivers/acpi/video.c +++ b/drivers/acpi/video.c @@ -37,6 +37,8 @@ #include <linux/thermal.h> #include <linux/video_output.h> #include <linux/sort.h> +#include <linux/pci.h> +#include <linux/pci_ids.h> #include <asm/uaccess.h> #include <acpi/acpi_bus.h> @@ -2251,7 +2253,27 @@ static int acpi_video_bus_remove(struct acpi_device *device, int type) return 0; } -static int __init acpi_video_init(void) +static int __init intel_opregion_present(void) +{ +#if defined(CONFIG_DRM_I915) || defined(CONFIG_DRM_I915_MODULE) + struct pci_dev *dev = NULL; + u32 address; + + for_each_pci_dev(dev) { + if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA) + continue; + if (dev->vendor != PCI_VENDOR_ID_INTEL) + continue; + pci_read_config_dword(dev, 0xfc, &address); + if (!address) + continue; + return 1; + } +#endif + return 0; +} + +int acpi_video_register(void) { int result = 0; @@ -2268,6 +2290,22 @@ static int __init acpi_video_init(void) return 0; } +EXPORT_SYMBOL(acpi_video_register); + +/* + * This is kind of nasty. Hardware using Intel chipsets may require + * the video opregion code to be run first in order to initialise + * state before any ACPI video calls are made. To handle this we defer + * registration of the video class until the opregion code has run. + */ + +static int __init acpi_video_init(void) +{ + if (intel_opregion_present()) + return 0; + + return acpi_video_register(); +} static void __exit acpi_video_exit(void) { |