Merge branch 'for-6.15/amd_sfh' into for-linus

From: Mario Limonciello <mario.limonciello@amd.com>

Some platforms include a human presence detection (HPD) sensor. When
enabled and a user is detected a wake event will be emitted from the
sensor fusion hub that software can react to.

Example use cases are "wake from suspend on approach" or to "lock
when leaving".

This is currently enabled by default on supported systems, but users
can't control it. This essentially means that wake on approach is
enabled which is a really surprising behavior to users that don't
expect it.

Instead of defaulting to enabled add a sysfs knob that users can
use to enable the feature if desirable and set it to disabled by
default.

1 files changed, 18 insertions, 7 deletions

diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index c0caa14880c3b..c0bdc1686154d 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -925,7 +925,7 @@ static int kexec_limit_handler(const struct ctl_table *table, int write,
 	return proc_dointvec(&tmp, write, buffer, lenp, ppos);
 }
 
-static struct ctl_table kexec_core_sysctls[] = {
+static const struct ctl_table kexec_core_sysctls[] = {
 	{
 		.procname	= "kexec_load_disabled",
 		.data		= &kexec_load_disabled,
@@ -1001,6 +1001,12 @@ int kernel_kexec(void)
 
 #ifdef CONFIG_KEXEC_JUMP
 	if (kexec_image->preserve_context) {
+		/*
+		 * This flow is analogous to hibernation flows that occur
+		 * before creating an image and before jumping from the
+		 * restore kernel to the image one, so it uses the same
+		 * device callbacks as those two flows.
+		 */
 		pm_prepare_console();
 		error = freeze_processes();
 		if (error) {
@@ -1011,12 +1017,10 @@ int kernel_kexec(void)
 		error = dpm_suspend_start(PMSG_FREEZE);
 		if (error)
 			goto Resume_console;
-		/* At this point, dpm_suspend_start() has been called,
-		 * but *not* dpm_suspend_end(). We *must* call
-		 * dpm_suspend_end() now.  Otherwise, drivers for
-		 * some devices (e.g. interrupt controllers) become
-		 * desynchronized with the actual state of the
-		 * hardware at resume time, and evil weirdness ensues.
+		/*
+		 * dpm_suspend_end() must be called after dpm_suspend_start()
+		 * to complete the transition, like in the hibernation flows
+		 * mentioned above.
 		 */
 		error = dpm_suspend_end(PMSG_FREEZE);
 		if (error)
@@ -1052,6 +1056,13 @@ int kernel_kexec(void)
 
 #ifdef CONFIG_KEXEC_JUMP
 	if (kexec_image->preserve_context) {
+		/*
+		 * This flow is analogous to hibernation flows that occur after
+		 * creating an image and after the image kernel has got control
+		 * back, and in case the devices have been reset or otherwise
+		 * manipulated in the meantime, it uses the device callbacks
+		 * used by the latter.
+		 */
 		syscore_resume();
  Enable_irqs:
 		local_irq_enable();