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_video.backlight=[video|vendor|native|none], and adding 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 --- drivers/acpi/video_detect.c | 172 +++++++++++++++++++++----------------------- include/acpi/video.h | 17 +++++ 2 files changed, 100 insertions(+), 89 deletions(-)
diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c index 0bc8b98..01c8c46 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 * @@ -9,28 +11,24 @@ * 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 <acpi/video.h> #include <linux/export.h> #include <linux/acpi.h> +#include <linux/backlight.h> #include <linux/dmi.h> #include <linux/module.h> #include <linux/pci.h> @@ -38,20 +36,24 @@ 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 char acpi_backlight_str[16]; module_param_string(backlight, acpi_backlight_str, 16, 0444); MODULE_PARM_DESC(backlight, - "Select which backlight interface to use [vendor|video]"); + "Select which backlight interface to use [vendor|video|native]");
static void acpi_video_parse_cmdline(void) { if (!strcmp("vendor", acpi_backlight_str)) - acpi_video_support |= ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR; + acpi_backlight_cmdline = acpi_backlight_vendor; if (!strcmp("video", acpi_backlight_str)) - acpi_video_support |= ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO; + acpi_backlight_cmdline = acpi_backlight_video; + if (!strcmp("native", acpi_backlight_str)) + acpi_backlight_cmdline = acpi_backlight_native; + if (!strcmp("none", acpi_backlight_str)) + acpi_backlight_cmdline = acpi_backlight_none; }
static acpi_status @@ -82,7 +84,7 @@ 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; }
@@ -130,99 +132,91 @@ static 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); diff --git a/include/acpi/video.h b/include/acpi/video.h index 843ef1a..01b5cc7 100644 --- a/include/acpi/video.h +++ b/include/acpi/video.h @@ -16,6 +16,14 @@ struct acpi_device; #define ACPI_VIDEO_DISPLAY_LEGACY_PANEL 0x0110 #define ACPI_VIDEO_DISPLAY_LEGACY_TV 0x0200
+enum acpi_backlight_type { + acpi_backlight_undef = -1, + acpi_backlight_none = 0, + acpi_backlight_video, + acpi_backlight_vendor, + acpi_backlight_native, +}; + #if (defined CONFIG_ACPI_VIDEO || defined CONFIG_ACPI_VIDEO_MODULE) extern int acpi_video_register(void); extern void acpi_video_unregister(void); @@ -23,6 +31,8 @@ extern void acpi_video_unregister_backlight(void); extern int acpi_video_get_edid(struct acpi_device *device, int type, int device_id, void **edid); extern bool acpi_video_verify_backlight_support(void); +extern enum acpi_backlight_type acpi_video_get_backlight_type(void); +extern void acpi_video_set_dmi_backlight_type(enum acpi_backlight_type type); #else static inline int acpi_video_register(void) { return 0; } static inline void acpi_video_unregister(void) { return; } @@ -33,6 +43,13 @@ static inline int acpi_video_get_edid(struct acpi_device *device, int type, return -ENODEV; } static inline bool acpi_video_verify_backlight_support(void) { return false; } +static inline enum acpi_backlight_type acpi_video_get_backlight_type(void) +{ + return acpi_backlight_vendor; +} +static void acpi_video_set_dmi_backlight_type(enum acpi_backlight_type type) +{ +} #endif
#endif