On 10/21/2025 3:43 PM, Pascal Ernster wrote:

[2025-10-20 10:36] gregkh linuxfoundation ! org:

...

This is a note to let you know that I've just added the patch titled

 PM: hibernate: Add pm_hibernation_mode_is_suspend()

to the 6.17-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: pm-hibernate-add-pm_hibernation_mode_is_suspend.patch and it can be found in the queue-6.17 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From stable+bounces-187839-greg=kroah.com@vger.kernel.org Sat Oct 18 15:51:25 2025 From: Sasha Levin sashal@kernel.org Date: Sat, 18 Oct 2025 09:51:01 -0400 Subject: PM: hibernate: Add pm_hibernation_mode_is_suspend() To: stable@vger.kernel.org Cc: "Mario Limonciello (AMD)" superm1@kernel.org, Ionut Nechita ionut_n2001@yahoo.com, Kenneth Crudup kenny@panix.com, Alex Deucher alexander.deucher@amd.com, "Rafael J. Wysocki" rafael.j.wysocki@intel.com, Sasha Levin sashal@kernel.org Message-ID: 20251018135102.711457-1-sashal@kernel.org

From: "Mario Limonciello (AMD)" superm1@kernel.org

[ Upstream commit 495c8d35035edb66e3284113bef01f3b1b843832 ]

Some drivers have different flows for hibernation and suspend. If the driver opportunistically will skip thaw() then it needs a hint to know what is happening after the hibernate.

Introduce a new symbol pm_hibernation_mode_is_suspend() that drivers can call to determine if suspending the system for this purpose.

Tested-by: Ionut Nechita ionut_n2001@yahoo.com Tested-by: Kenneth Crudup kenny@panix.com Acked-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Mario Limonciello (AMD) superm1@kernel.org Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Stable-dep-of: 0a6e9e098fcc ("drm/amd: Fix hybrid sleep") Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

---

include/linux/suspend.h | 2 ++ kernel/power/hibernate.c | 11 +++++++++++ 2 files changed, 13 insertions(+)

--- a/include/linux/suspend.h +++ b/include/linux/suspend.h @@ -276,6 +276,7 @@ extern void arch_suspend_enable_irqs(voi extern int pm_suspend(suspend_state_t state); extern bool sync_on_suspend_enabled; +bool pm_hibernation_mode_is_suspend(void); #else /* !CONFIG_SUSPEND */ #define suspend_valid_only_mem NULL @@ -288,6 +289,7 @@ static inline bool pm_suspend_via_firmwa static inline bool pm_resume_via_firmware(void) { return false; } static inline bool pm_suspend_no_platform(void) { return false; } static inline bool pm_suspend_default_s2idle(void) { return false; } +static inline bool pm_hibernation_mode_is_suspend(void) { return false; } static inline void suspend_set_ops(const struct platform_suspend_ops *ops) {} static inline int pm_suspend(suspend_state_t state) { return -ENOSYS; } --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -80,6 +80,17 @@ static const struct platform_hibernation static atomic_t hibernate_atomic = ATOMIC_INIT(1); +#ifdef CONFIG_SUSPEND +/**

• • pm_hibernation_mode_is_suspend - Check if hibernation has been set to suspend
• */

+bool pm_hibernation_mode_is_suspend(void) +{

• return hibernation_mode == HIBERNATION_SUSPEND;

+} +EXPORT_SYMBOL_GPL(pm_hibernation_mode_is_suspend); +#endif

• bool hibernate_acquire(void) { return atomic_add_unless(&hibernate_atomic, -1, 0);

Patches currently in stable-queue which might be from sashal@kernel.org are

queue-6.17/drm-amd-fix-hybrid-sleep.patch queue-6.17/usb-gadget-introduce-free_usb_request-helper.patch queue-6.17/pm-hibernate-add-pm_hibernation_mode_is_suspend.patch queue-6.17/usb-gadget-store-endpoint-pointer-in-usb_request.patch queue-6.17/media-nxp-imx8-isi-m2m-fix-streaming-cleanup-on-release.patch queue-6.17/usb-gadget-f_rndis-refactor-bind-path-to-use-__free.patch

Hi,

I kept getting "ERROR: modpost: "pm_hibernation_mode_is_suspend" [drivers/gpu/drm/amd/amdgpu/amdgpu.ko] undefined!" when trying to build a 6.17.4 kernel with all the patches from queue-6.17 applied on top (from the stable-queue git repo at commit id 6aceec507fd0d3cefa7cac227eaf897edf09bf32). That build-time error is gone and the resulting kernel boots/runs fine on various x86_64 machines and VMs since I've removed/omitted both this patch and queue-6.17/drm-amd-fix-hybrid-sleep.patch.

I'm not sure if omitting queue-6.17/drm-amd-fix-hybrid-sleep.patch would have been sufficient, but both patches are part of the same patch set anyway.

Sadly, I haven't been able to figure out what about the changes actually causes the issue. My first guess was that if CONFIG_SUSPEND is not selected/enabled, then the whole pm_hibernation_mode_is_suspend() function and the corresponding export symbol would be missing. However, the kernel that I was trying to build *does* have CONFIG_SUSPEND=y in its config, so this shouldn't be the cause…

Regards Pascal

Are you cleaning your tree between builds?