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author | Hans de Goede <hdegoede@redhat.com> | 2015-06-16 16:27:48 +0200 |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2015-06-19 01:10:44 +0200 |
commit | 87521e16a7abbf3fa337f56cb4d1e18247f15e8a (patch) | |
tree | 63ae44bbc4a4aaf0b48f03536c825d36baaf4238 /drivers/acpi/video_detect.c | |
parent | 14ca7a47d0ab2a7a35faab130e6d9682f8ff1a46 (diff) | |
download | linux-87521e16a7abbf3fa337f56cb4d1e18247f15e8a.tar.gz linux-87521e16a7abbf3fa337f56cb4d1e18247f15e8a.tar.bz2 linux-87521e16a7abbf3fa337f56cb4d1e18247f15e8a.zip |
acpi-video-detect: Rewrite backlight interface selection logic
Currently we have 2 kernel commandline options + dmi-quirks in 3 places all
interacting (in interesting ways) to select which which backlight interface
to use. On the commandline we've acpi_backlight=[video|vendor] and
video.use_native_backlight=[0|1]. DMI quirks we have in
acpi/video-detect.c, acpi/video.c and drivers/platform/x86/*.c .
This commit is the first step to cleaning this up, replacing the 2 cmdline
options with just acpi_backlight=[video|vendor|native|none], and adds a
new API to video_detect.c to reflect this.
Follow up commits will also move other related code, like unregistering the
acpi_video backlight interface if it was registered before other drivers
which take priority over it are loaded, to video_detect.c where this
logic really belongs.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/video_detect.c')
-rw-r--r-- | drivers/acpi/video_detect.c | 171 |
1 files changed, 83 insertions, 88 deletions
diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c index bb6133c60175..0f9586b7f3d1 100644 --- a/drivers/acpi/video_detect.c +++ b/drivers/acpi/video_detect.c @@ -1,4 +1,6 @@ /* + * Copyright (C) 2015 Red Hat Inc. + * Hans de Goede <hdegoede@redhat.com> * Copyright (C) 2008 SuSE Linux Products GmbH * Thomas Renninger <trenn@suse.de> * @@ -9,44 +11,45 @@ * acpi_get_pci_dev() can be called to identify ACPI graphics * devices for which a real graphics card is plugged in * - * Now acpi_video_get_capabilities() can be called to check which - * capabilities the graphics cards plugged in support. The check for general - * video capabilities will be triggered by the first caller of - * acpi_video_get_capabilities(NULL); which will happen when the first - * backlight switching supporting driver calls: - * acpi_video_backlight_support(); - * * Depending on whether ACPI graphics extensions (cmp. ACPI spec Appendix B) * are available, video.ko should be used to handle the device. * * Otherwise vendor specific drivers like thinkpad_acpi, asus-laptop, * sony_acpi,... can take care about backlight brightness. * - * If CONFIG_ACPI_VIDEO is neither set as "compiled in" (y) nor as a module (m) - * this file will not be compiled, acpi_video_get_capabilities() and - * acpi_video_backlight_support() will always return 0 and vendor specific - * drivers always can handle backlight. + * Backlight drivers can use acpi_video_get_backlight_type() to determine + * which driver should handle the backlight. * + * If CONFIG_ACPI_VIDEO is neither set as "compiled in" (y) nor as a module (m) + * this file will not be compiled and acpi_video_get_backlight_type() will + * always return acpi_backlight_vendor. */ #include <linux/export.h> #include <linux/acpi.h> +#include <linux/backlight.h> #include <linux/dmi.h> #include <linux/module.h> #include <linux/pci.h> +#include <linux/types.h> +#include <acpi/video.h> ACPI_MODULE_NAME("video"); #define _COMPONENT ACPI_VIDEO_COMPONENT -static long acpi_video_support; -static bool acpi_video_caps_checked; +static enum acpi_backlight_type acpi_backlight_cmdline = acpi_backlight_undef; +static enum acpi_backlight_type acpi_backlight_dmi = acpi_backlight_undef; static void acpi_video_parse_cmdline(void) { if (!strcmp("vendor", acpi_video_backlight_string)) - acpi_video_support |= ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR; + acpi_backlight_cmdline = acpi_backlight_vendor; if (!strcmp("video", acpi_video_backlight_string)) - acpi_video_support |= ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO; + acpi_backlight_cmdline = acpi_backlight_video; + if (!strcmp("native", acpi_video_backlight_string)) + acpi_backlight_cmdline = acpi_backlight_native; + if (!strcmp("none", acpi_video_backlight_string)) + acpi_backlight_cmdline = acpi_backlight_none; } static acpi_status @@ -77,7 +80,7 @@ find_video(acpi_handle handle, u32 lvl, void *context, void **rv) * buggy */ static int video_detect_force_vendor(const struct dmi_system_id *d) { - acpi_video_support |= ACPI_VIDEO_BACKLIGHT_DMI_VENDOR; + acpi_backlight_dmi = acpi_backlight_vendor; return 0; } @@ -125,99 +128,91 @@ static const struct dmi_system_id video_detect_dmi_table[] = { }; /* - * Returns the video capabilities of a specific ACPI graphics device + * Determine which type of backlight interface to use on this system, + * First check cmdline, then dmi quirks, then do autodetect. + * + * The autodetect order is: + * 1) Is the acpi-video backlight interface supported -> + * no, use a vendor interface + * 2) Is this a win8 "ready" BIOS and do we have a native interface -> + * yes, use a native interface + * 3) Else use the acpi-video interface * - * if NULL is passed as argument all ACPI devices are enumerated and - * all graphics capabilities of physically present devices are - * summarized and returned. This is cached and done only once. + * Arguably the native on win8 check should be done first, but that would + * be a behavior change, which may causes issues. */ -static long acpi_video_get_capabilities(acpi_handle graphics_handle) +enum acpi_backlight_type acpi_video_get_backlight_type(void) { - long caps = 0; - struct acpi_device *tmp_dev; - acpi_status status; - - if (acpi_video_caps_checked && graphics_handle == NULL) - return acpi_video_support; - - if (!graphics_handle) { - /* Only do the global walk through all graphics devices once */ - acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, - ACPI_UINT32_MAX, find_video, NULL, - &caps, NULL); - /* There might be boot param flags set already... */ - acpi_video_support |= caps; - acpi_video_caps_checked = 1; - /* Add blacklists here. Be careful to use the right *DMI* bits - * to still be able to override logic via boot params, e.g.: - * - * if (dmi_name_in_vendors("XY")) { - * acpi_video_support |= - * ACPI_VIDEO_BACKLIGHT_DMI_VENDOR; - *} - */ + static DEFINE_MUTEX(init_mutex); + static bool init_done; + static long video_caps; + /* Parse cmdline, dmi and acpi only once */ + mutex_lock(&init_mutex); + if (!init_done) { + acpi_video_parse_cmdline(); dmi_check_system(video_detect_dmi_table); - } else { - status = acpi_bus_get_device(graphics_handle, &tmp_dev); - if (ACPI_FAILURE(status)) { - ACPI_EXCEPTION((AE_INFO, status, "Invalid device")); - return 0; - } - acpi_walk_namespace(ACPI_TYPE_DEVICE, graphics_handle, + acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, ACPI_UINT32_MAX, find_video, NULL, - &caps, NULL); + &video_caps, NULL); + init_done = true; } - ACPI_DEBUG_PRINT((ACPI_DB_INFO, "We have 0x%lX video support %s %s\n", - graphics_handle ? caps : acpi_video_support, - graphics_handle ? "on device " : "in general", - graphics_handle ? acpi_device_bid(tmp_dev) : "")); - return caps; + mutex_unlock(&init_mutex); + + if (acpi_backlight_cmdline != acpi_backlight_undef) + return acpi_backlight_cmdline; + + if (acpi_backlight_dmi != acpi_backlight_undef) + return acpi_backlight_dmi; + + if (!(video_caps & ACPI_VIDEO_BACKLIGHT)) + return acpi_backlight_vendor; + + if (acpi_osi_is_win8() && backlight_device_registered(BACKLIGHT_RAW)) + return acpi_backlight_native; + + return acpi_backlight_video; } +EXPORT_SYMBOL(acpi_video_get_backlight_type); -static void acpi_video_caps_check(void) +/* + * Set the preferred backlight interface type based on DMI info. + * This function allows DMI blacklists to be implemented by external + * platform drivers instead of putting a big blacklist in video_detect.c + */ +void acpi_video_set_dmi_backlight_type(enum acpi_backlight_type type) { - /* - * We must check whether the ACPI graphics device is physically plugged - * in. Therefore this must be called after binding PCI and ACPI devices - */ - if (!acpi_video_caps_checked) { - acpi_video_parse_cmdline(); - acpi_video_get_capabilities(NULL); - } + acpi_backlight_dmi = type; } +EXPORT_SYMBOL(acpi_video_set_dmi_backlight_type); -/* Promote the vendor interface instead of the generic video module. - * This function allow DMI blacklists to be implemented by externals - * platform drivers instead of putting a big blacklist in video_detect.c +/* + * Compatiblity function, this is going away as soon as all drivers are + * converted to acpi_video_set_dmi_backlight_type(). + * + * Promote the vendor interface instead of the generic video module. * After calling this function you will probably want to call * acpi_video_unregister() to make sure the video module is not loaded */ void acpi_video_dmi_promote_vendor(void) { - acpi_video_caps_check(); - acpi_video_support |= ACPI_VIDEO_BACKLIGHT_DMI_VENDOR; + acpi_video_set_dmi_backlight_type(acpi_backlight_vendor); } EXPORT_SYMBOL(acpi_video_dmi_promote_vendor); -/* Returns true if video.ko can do backlight switching */ +/* + * Compatiblity function, this is going away as soon as all drivers are + * converted to acpi_video_get_backlight_type(). + * + * Returns true if video.ko can do backlight switching. + */ int acpi_video_backlight_support(void) { - acpi_video_caps_check(); - - /* First check for boot param -> highest prio */ - if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR) - return 0; - else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO) - return 1; - - /* Then check for DMI blacklist -> second highest prio */ - if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VENDOR) - return 0; - else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VIDEO) - return 1; - - /* Then go the default way */ - return acpi_video_support & ACPI_VIDEO_BACKLIGHT; + /* + * This is done this way since vendor drivers call this to see + * if they should load, and we do not want them to load for both + * the acpi_backlight_video and acpi_backlight_native cases. + */ + return acpi_video_get_backlight_type() != acpi_backlight_vendor; } EXPORT_SYMBOL(acpi_video_backlight_support); |