linux.git/kernel/power, branch v6.12.81

PM: hibernate: Drain trailing zero pages on userspace restore

2026-04-02T11:09:39+00:00

[ Upstream commit 734eba62cd32cb9ceffa09e57cdc03d761528525 ]

Commit 005e8dddd497 ("PM: hibernate: don't store zero pages in the
image file") added an optimization to skip zero-filled pages in the
hibernation image. On restore, zero pages are handled internally by
snapshot_write_next() in a loop that processes them without returning
to the caller.

With the userspace restore interface, writing the last non-zero page
to /dev/snapshot is followed by the SNAPSHOT_ATOMIC_RESTORE ioctl. At
this point there are no more calls to snapshot_write_next() so any
trailing zero pages are not processed, snapshot_image_loaded() fails
because handle->cur is smaller than expected, the ioctl returns -EPERM
and the image is not restored.

The in-kernel restore path is not affected by this because the loop in
load_image() in swap.c calls snapshot_write_next() until it returns 0.
It is this final call that drains any trailing zero pages.

Fixed by calling snapshot_write_next() in snapshot_write_finalize(),
giving the kernel the chance to drain any trailing zero pages.

Fixes: 005e8dddd497 ("PM: hibernate: don't store zero pages in the image file")
Signed-off-by: Alberto Garcia 
Acked-by: Brian Geffon 
Link: https://patch.msgid.link/ef5a7c5e3e3dbd17dcb20efaa0c53a47a23498bb.1773075892.git.berto@igalia.com
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

PM: hibernate: Use atomic64_t for compressed_size variable

2025-11-24T09:36:03+00:00

commit 66ededc694f1d06a71ca35a3c8e3689e9b85b3ce upstream.

`compressed_size` can overflow, showing nonsensical values.

Change from `atomic_t` to `atomic64_t` to prevent overflow.

Fixes: a06c6f5d3cc9 ("PM: hibernate: Move to crypto APIs for LZO compression")
Reported-by: Askar Safin 
Closes: https://lore.kernel.org/linux-pm/20251105180506.137448-1-safinaskar@gmail.com/
Signed-off-by: Mario Limonciello (AMD) 
Tested-by: Askar Safin 
Cc: 6.9+  # 6.9+
Link: https://patch.msgid.link/20251106045158.3198061-3-superm1@kernel.org
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

PM: hibernate: Emit an error when image writing fails

2025-11-24T09:36:03+00:00

commit 62b9ca1706e1bbb60d945a58de7c7b5826f6b2a2 upstream.

If image writing fails, a return code is passed up to the caller, but
none of the callers log anything to the log and so the only record
of it is the return code that userspace gets.

Adjust the logging so that the image size and speed of writing is
only emitted on success and if there is an error, it's saved to the
logs.

Fixes: a06c6f5d3cc9 ("PM: hibernate: Move to crypto APIs for LZO compression")
Reported-by: Askar Safin 
Closes: https://lore.kernel.org/linux-pm/20251105180506.137448-1-safinaskar@gmail.com/
Signed-off-by: Mario Limonciello (AMD) 
Tested-by: Askar Safin 
Cc: 6.9+  # 6.9+
[ rjw: Added missing braces after "else", changelog edits ]
Link: https://patch.msgid.link/20251106045158.3198061-2-superm1@kernel.org
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

PM: EM: Fix late boot with holes in CPU topology

2025-10-29T13:08:53+00:00

[ Upstream commit 1ebe8f7e782523e62cd1fa8237f7afba5d1dae83 ]

Commit e3f1164fc9ee ("PM: EM: Support late CPUs booting and capacity
adjustment") added a mechanism to handle CPUs that come up late by
retrying when any of the `cpufreq_cpu_get()` call fails.

However, if there are holes in the CPU topology (offline CPUs, e.g.
nosmt), the first missing CPU causes the loop to break, preventing
subsequent online CPUs from being updated.

Instead of aborting on the first missing CPU policy, loop through all
and retry if any were missing.

Fixes: e3f1164fc9ee ("PM: EM: Support late CPUs booting and capacity adjustment")
Suggested-by: Kenneth Crudup 
Reported-by: Kenneth Crudup 
Link: https://lore.kernel.org/linux-pm/40212796-734c-4140-8a85-854f72b8144d@panix.com/
Cc: 6.9+  # 6.9+
Signed-off-by: Christian Loehle 
Link: https://patch.msgid.link/20250831214357.2020076-1-christian.loehle@arm.com
[ rjw: Drop the new pr_debug() message which is not very useful ]
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

PM: EM: Move CPU capacity check to em_adjust_new_capacity()

2025-10-29T13:08:53+00:00

[ Upstream commit 3e3ba654d3097e0031f2add215b12ff81c23814e ]

Move the check of the CPU capacity currently stored in the energy model
against the arch_scale_cpu_capacity() value to em_adjust_new_capacity()
so it will be done regardless of where the latter is called from.

This will be useful when a new em_adjust_new_capacity() caller is added
subsequently.

While at it, move the pd local variable declaration in
em_check_capacity_update() into the loop in which it is used.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Lukasz Luba 
Tested-by: Christian Loehle 
Reviewed-by: Dietmar Eggemann 
Link: https://patch.msgid.link/7810787.EvYhyI6sBW@rjwysocki.net
Stable-dep-of: 1ebe8f7e7825 ("PM: EM: Fix late boot with holes in CPU topology")
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

PM: EM: Slightly reduce em_check_capacity_update() overhead

2025-10-29T13:08:53+00:00

[ Upstream commit a8e62726ac0dd7b610c87ba1a938a5a9091c34df ]

Every iteration of the loop over all possible CPUs in
em_check_capacity_update() causes get_cpu_device() to be called twice
for the same CPU, once indirectly via em_cpu_get() and once directly.

Get rid of the indirect get_cpu_device() call by moving the direct
invocation of it earlier and using em_pd_get() instead of em_cpu_get()
to get a pd pointer for the dev one returned by it.

This also exposes the fact that dev is needed to get a pd, so the code
becomes somewhat easier to follow after it.

No functional impact.

Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Lukasz Luba 
Link: https://patch.msgid.link/1925950.tdWV9SEqCh@rjwysocki.net
Stable-dep-of: 1ebe8f7e7825 ("PM: EM: Fix late boot with holes in CPU topology")
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

PM: EM: Drop unused parameter from em_adjust_new_capacity()

2025-10-29T13:08:53+00:00

[ Upstream commit 5fad775d432c6c9158ea12e7e00d8922ef8d3dfc ]

The max_cap parameter is never used in em_adjust_new_capacity(), so
drop it.

No functional impact.

Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Lukasz Luba 
Link: https://patch.msgid.link/2369979.ElGaqSPkdT@rjwysocki.net
Stable-dep-of: 1ebe8f7e7825 ("PM: EM: Fix late boot with holes in CPU topology")
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

PM: sleep: console: Fix the black screen issue

2025-08-20T16:30:25+00:00

[ Upstream commit 4266e8fa56d3d982bf451d382a410b9db432015c ]

When the computer enters sleep status without a monitor
connected, the system switches the console to the virtual
terminal tty63(SUSPEND_CONSOLE).

If a monitor is subsequently connected before waking up,
the system skips the required VT restoration process
during wake-up, leaving the console on tty63 instead of
switching back to tty1.

To fix this issue, a global flag vt_switch_done is introduced
to record whether the system has successfully switched to
the suspend console via vt_move_to_console() during suspend.

If the switch was completed, vt_switch_done is set to 1.
Later during resume, this flag is checked to ensure that
the original console is restored properly by calling
vt_move_to_console(orig_fgconsole, 0).

This prevents scenarios where the resume logic skips console
restoration due to incorrect detection of the console state,
especially when a monitor is reconnected before waking up.

Signed-off-by: tuhaowen 
Link: https://patch.msgid.link/20250611032345.29962-1-tuhaowen@uniontech.com
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

PM: sleep: Print PM debug messages during hibernation

2025-06-19T13:31:32+00:00

[ Upstream commit 1b17d4525bca3916644c41e01522df8fa0f8b90b ]

Commit cdb8c100d8a4 ("include/linux/suspend.h: Only show pm_pr_dbg
messages at suspend/resume") caused PM debug messages to only be
printed during system-wide suspend and resume in progress, but it
forgot about hibernation.

Address this by adding a check for hibernation in progress to
pm_debug_messages_should_print().

Fixes: cdb8c100d8a4 ("include/linux/suspend.h: Only show pm_pr_dbg messages at suspend/resume")
Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Mario Limonciello 
Link: https://patch.msgid.link/4998903.GXAFRqVoOG@rjwysocki.net
Signed-off-by: Sasha Levin

PM: wakeup: Delete space in the end of string shown by pm_show_wakelocks()

2025-06-19T13:31:32+00:00

[ Upstream commit f0050a3e214aa941b78ad4caf122a735a24d81a6 ]

pm_show_wakelocks() is called to generate a string when showing
attributes /sys/power/wake_(lock|unlock), but the string ends
with an unwanted space that was added back by mistake by commit
c9d967b2ce40 ("PM: wakeup: simplify the output logic of
pm_show_wakelocks()").

Remove the unwanted space.

Fixes: c9d967b2ce40 ("PM: wakeup: simplify the output logic of pm_show_wakelocks()")
Signed-off-by: Zijun Hu 
Link: https://patch.msgid.link/20250505-fix_power-v1-1-0f7f2c2f338c@quicinc.com
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin