The Lenovo ThinkPad W530 uses a nvidia k1000m GPU. When this gets used
together with one of the older nvidia binary driver series (the latest
series does not support it), then backlight control does not work.
This is caused by commit 3dbc80a3e4c5 ("ACPI: video: Make backlight
class device registration a separate step (v2)") combined with
commit 5aa9d943e9b6 ("ACPI: video: Don't enable fallback path for
creating ACPI backlight by default").
After these changes the acpi_video# backlight device is only registered
when requested by a GPU driver calling acpi_video_register_backlight()
which the nvidia binary driver does not do.
I realize that using the nvidia binary driver is not a supported use-case
and users can workaround this by adding acpi_backlight=video on the kernel
commandline, but the ThinkPad W530 is a popular model under Linux users,
so it seems worthwhile to add a quirk for this.
I will also email Nvidia asking them to make the driver call
acpi_video_register_backlight() when an internal LCD panel is detected.
So maybe the next maintenance release of the drivers will fix this...
Fixes: 5aa9d943e9b6 ("ACPI: video: Don't enable fallback path for creating ACPI backlight by default")
Cc: stable(a)vger.kernel.org
Reviewed-by: Mario Limonciello <mario.limonciello(a)amd.com>
Signed-off-by: Hans de Goede <hdegoede(a)redhat.com>
---
drivers/acpi/video_detect.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
index 295744fe7c92..e85729fc481f 100644
--- a/drivers/acpi/video_detect.c
+++ b/drivers/acpi/video_detect.c
@@ -299,6 +299,20 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
},
},
+ /*
+ * Older models with nvidia GPU which need acpi_video backlight
+ * control and where the old nvidia binary driver series does not
+ * call acpi_video_register_backlight().
+ */
+ {
+ .callback = video_detect_force_video,
+ /* ThinkPad W530 */
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+ DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad W530"),
+ },
+ },
+
/*
* These models have a working acpi_video backlight control, and using
* native backlight causes a regression where backlight does not work
--
2.39.1
On the Apple iMac14,1 and iMac14,2 all-in-ones (monitors with builtin "PC")
the connection between the GPU and the panel is seen by the GPU driver as
regular DP instead of eDP, causing the GPU driver to never call
acpi_video_register_backlight().
(GPU drivers only call acpi_video_register_backlight() when an internal
panel is detected, to avoid non working acpi_video# devices getting
registered on desktops which unfortunately is a real issue.)
Fix the missing acpi_video# backlight device on these all-in-ones by
adding a acpi_backlight=video DMI quirk, so that video.ko will
immediately register the backlight device instead of waiting for
an acpi_video_register_backlight() call.
Fixes: 5aa9d943e9b6 ("ACPI: video: Don't enable fallback path for creating ACPI backlight by default")
Cc: stable(a)vger.kernel.org
Reviewed-by: Mario Limonciello <mario.limonciello(a)amd.com>
Signed-off-by: Hans de Goede <hdegoede(a)redhat.com>
---
drivers/acpi/video_detect.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
index f7c218dd8742..295744fe7c92 100644
--- a/drivers/acpi/video_detect.c
+++ b/drivers/acpi/video_detect.c
@@ -276,6 +276,29 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
},
},
+ /*
+ * Models which need acpi_video backlight control where the GPU drivers
+ * do not call acpi_video_register_backlight() because no internal panel
+ * is detected. Typically these are all-in-ones (monitors with builtin
+ * PC) where the panel connection shows up as regular DP instead of eDP.
+ */
+ {
+ .callback = video_detect_force_video,
+ /* Apple iMac14,1 */
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+ DMI_MATCH(DMI_PRODUCT_NAME, "iMac14,1"),
+ },
+ },
+ {
+ .callback = video_detect_force_video,
+ /* Apple iMac14,2 */
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+ DMI_MATCH(DMI_PRODUCT_NAME, "iMac14,2"),
+ },
+ },
+
/*
* These models have a working acpi_video backlight control, and using
* native backlight causes a regression where backlight does not work
--
2.39.1
Commit 3dbc80a3e4c5 ("ACPI: video: Make backlight class device
registration a separate step (v2)") combined with
commit 5aa9d943e9b6 ("ACPI: video: Don't enable fallback path for
creating ACPI backlight by default")
Means that the video.ko code now fully depends on the GPU driver calling
acpi_video_register_backlight() for the acpi_video# backlight class
devices to get registered.
This means that if the GPU driver does not do this, acpi_backlight=video
on the cmdline, or DMI quirks for selecting acpi_video# will not work.
This is a problem on for example Apple iMac14,1 all-in-ones where
the monitor's LCD panel shows up as a regular DP connection instead of
eDP so the GPU driver will not call acpi_video_register_backlight() [1].
Fix this by making video.ko directly register the acpi_video# devices
when these have been explicitly requested either on the cmdline or
through DMI quirks (rather then auto-detection being used).
[1] GPU drivers only call acpi_video_register_backlight() when an internal
panel is detected, to avoid non working acpi_video# devices getting
registered on desktops which unfortunately is a real issue.
Fixes: 5aa9d943e9b6 ("ACPI: video: Don't enable fallback path for creating ACPI backlight by default")
Cc: stable(a)vger.kernel.org
Reviewed-by: Mario Limonciello <mario.limonciello(a)amd.com>
Signed-off-by: Hans de Goede <hdegoede(a)redhat.com>
---
drivers/acpi/acpi_video.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/drivers/acpi/acpi_video.c b/drivers/acpi/acpi_video.c
index 97b711e57bff..c7a6d0b69dab 100644
--- a/drivers/acpi/acpi_video.c
+++ b/drivers/acpi/acpi_video.c
@@ -1984,6 +1984,7 @@ static int instance;
static int acpi_video_bus_add(struct acpi_device *device)
{
struct acpi_video_bus *video;
+ bool auto_detect;
int error;
acpi_status status;
@@ -2045,10 +2046,20 @@ static int acpi_video_bus_add(struct acpi_device *device)
mutex_unlock(&video_list_lock);
/*
- * The userspace visible backlight_device gets registered separately
- * from acpi_video_register_backlight().
+ * If backlight-type auto-detection is used then a native backlight may
+ * show up later and this may change the result from video to native.
+ * Therefor normally the userspace visible /sys/class/backlight device
+ * gets registered separately by the GPU driver calling
+ * acpi_video_register_backlight() when an internal panel is detected.
+ * Register the backlight now when not using auto-detection, so that
+ * when the kernel cmdline or DMI-quirks are used the backlight will
+ * get registered even if acpi_video_register_backlight() is not called.
*/
acpi_video_run_bcl_for_osi(video);
+ if (__acpi_video_get_backlight_type(false, &auto_detect) == acpi_backlight_video &&
+ !auto_detect)
+ acpi_video_bus_register_backlight(video);
+
acpi_video_bus_add_notify_handler(video);
return 0;
--
2.39.1
Allow callers of __acpi_video_get_backlight_type() to pass a pointer
to a bool which will get set to false if the backlight-type comes from
the cmdline or a DMI quirk and set to true if auto-detection was used.
And make __acpi_video_get_backlight_type() non static so that it can
be called directly outside of video_detect.c .
While at it turn the acpi_video_get_backlight_type() and
acpi_video_backlight_use_native() wrappers into static inline functions
in include/acpi/video.h, so that we need to export one less symbol.
Fixes: 5aa9d943e9b6 ("ACPI: video: Don't enable fallback path for creating ACPI backlight by default")
Cc: stable(a)vger.kernel.org
Reviewed-by: Mario Limonciello <mario.limonciello(a)amd.com>
Signed-off-by: Hans de Goede <hdegoede(a)redhat.com>
---
drivers/acpi/video_detect.c | 21 ++++++++-------------
include/acpi/video.h | 15 +++++++++++++--
2 files changed, 21 insertions(+), 15 deletions(-)
diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
index fd7cbce8076e..f7c218dd8742 100644
--- a/drivers/acpi/video_detect.c
+++ b/drivers/acpi/video_detect.c
@@ -782,7 +782,7 @@ static bool prefer_native_over_acpi_video(void)
* Determine which type of backlight interface to use on this system,
* First check cmdline, then dmi quirks, then do autodetect.
*/
-static enum acpi_backlight_type __acpi_video_get_backlight_type(bool native)
+enum acpi_backlight_type __acpi_video_get_backlight_type(bool native, bool *auto_detect)
{
static DEFINE_MUTEX(init_mutex);
static bool nvidia_wmi_ec_present;
@@ -807,6 +807,9 @@ static enum acpi_backlight_type __acpi_video_get_backlight_type(bool native)
native_available = true;
mutex_unlock(&init_mutex);
+ if (auto_detect)
+ *auto_detect = false;
+
/*
* The below heuristics / detection steps are in order of descending
* presedence. The commandline takes presedence over anything else.
@@ -818,6 +821,9 @@ static enum acpi_backlight_type __acpi_video_get_backlight_type(bool native)
if (acpi_backlight_dmi != acpi_backlight_undef)
return acpi_backlight_dmi;
+ if (auto_detect)
+ *auto_detect = true;
+
/* Special cases such as nvidia_wmi_ec and apple gmux. */
if (nvidia_wmi_ec_present)
return acpi_backlight_nvidia_wmi_ec;
@@ -837,15 +843,4 @@ static enum acpi_backlight_type __acpi_video_get_backlight_type(bool native)
/* No ACPI video/native (old hw), use vendor specific fw methods. */
return acpi_backlight_vendor;
}
-
-enum acpi_backlight_type acpi_video_get_backlight_type(void)
-{
- return __acpi_video_get_backlight_type(false);
-}
-EXPORT_SYMBOL(acpi_video_get_backlight_type);
-
-bool acpi_video_backlight_use_native(void)
-{
- return __acpi_video_get_backlight_type(true) == acpi_backlight_native;
-}
-EXPORT_SYMBOL(acpi_video_backlight_use_native);
+EXPORT_SYMBOL(__acpi_video_get_backlight_type);
diff --git a/include/acpi/video.h b/include/acpi/video.h
index 8ed9bec03e53..ff5a8da5d883 100644
--- a/include/acpi/video.h
+++ b/include/acpi/video.h
@@ -59,8 +59,6 @@ extern void acpi_video_unregister(void);
extern void acpi_video_register_backlight(void);
extern int acpi_video_get_edid(struct acpi_device *device, int type,
int device_id, void **edid);
-extern enum acpi_backlight_type acpi_video_get_backlight_type(void);
-extern bool acpi_video_backlight_use_native(void);
/*
* Note: The value returned by acpi_video_handles_brightness_key_presses()
* may change over time and should not be cached.
@@ -69,6 +67,19 @@ extern bool acpi_video_handles_brightness_key_presses(void);
extern int acpi_video_get_levels(struct acpi_device *device,
struct acpi_video_device_brightness **dev_br,
int *pmax_level);
+
+extern enum acpi_backlight_type __acpi_video_get_backlight_type(bool native,
+ bool *auto_detect);
+
+static inline enum acpi_backlight_type acpi_video_get_backlight_type(void)
+{
+ return __acpi_video_get_backlight_type(false, NULL);
+}
+
+static inline bool acpi_video_backlight_use_native(void)
+{
+ return __acpi_video_get_backlight_type(true, NULL) == acpi_backlight_native;
+}
#else
static inline void acpi_video_report_nolcd(void) { return; };
static inline int acpi_video_register(void) { return -ENODEV; }
--
2.39.1