+dri-devel
For those joining late; this is the full series for context.
https://lore.kernel.org/linux-pm/20240919171952.403745-1-lkml@xxxxxxxxxxx/T/#maee308be5349d8df25c8ccf12144ea96bbd4cbbd
On 9/19/2024 12:19, Antheas Kapenekakis wrote:
Currently, the screen off/on calls are handled within the suspend
sequence, which is a deviation from Windows. This causes issues with
certain devices, such as the ROG Ally, which expects this call to be
executed with the kernel fully awake. The subsequent half-suspended
state makes the controller of the device to fail to suspend properly.
This patch calls the screen off/on callbacks before entering the suspend
sequence, which fixes this issue. In addition, it opens the possibility
of modelling a state such as "Screen Off" that mirrors Windows, as the
callbacks will be accessible and validated to work outside of the
suspend sequence.
Signed-off-by: Antheas Kapenekakis <lkml@xxxxxxxxxxx>
---
kernel/power/suspend.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 19734b297527..afa95271ef00 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -507,6 +507,19 @@ int suspend_devices_and_enter(suspend_state_t state)
pm_suspend_target_state = state;
+ /*
+ * Linux does not have the concept of a "Screen Off" state, so call
+ * the platform functions for screen off prior to beginning the suspend
+ * sequence, mirroring Windows which calls them outside of it as well.
+ *
+ * If Linux ever gains a "Screen Off" state, the following callbacks can
+ * be replaced with a call that checks if we are in "Screen Off", in which
+ * case they will NOOP and if not call them as a fallback.
+ */
+ error = platform_suspend_screen_off();
It's a bit muddy; but I wonder if calling
drm_atomic_helper_disable_all() makes sense here.
+ if (error)
+ goto Screen_on;
+
if (state == PM_SUSPEND_TO_IDLE)
pm_set_suspend_no_platform();
@@ -540,6 +553,9 @@ int suspend_devices_and_enter(suspend_state_t state)
Close:
platform_resume_end(state);
pm_suspend_target_state = PM_SUSPEND_ON;
+
+ Screen_on:
+ platform_suspend_screen_on();
The problem with my suggestion above is what would you put here for
symmetry? drm_atomic_helper_resume() doesn't look right to me.
Maybe it's a no-op from DRM perspective and the drivers handle it.
return error;
Recover_platform:
