[PATCH v2 07/32] acpi-video-detect: Rewrite backlight interface selection logic
Hans de Goede
hdegoede at redhat.com
Fri Jun 12 04:23:26 PDT 2015
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 at redhat.com>
---
drivers/acpi/video_detect.c | 171 +++++++++++++++++++++-----------------------
include/acpi/video.h | 17 +++++
2 files changed, 100 insertions(+), 88 deletions(-)
diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
index 9af6768..1ae7536 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 at redhat.com>
* Copyright (C) 2008 SuSE Linux Products GmbH
* Thomas Renninger <trenn at 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 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
--
2.4.2
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