<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers/base/power, branch v5.16</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>PM: sleep: Fix error handling in dpm_prepare()</title>
<updated>2021-12-17T17:36:08+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2021-12-16T19:30:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=544e737dea5ad1a457f25dbddf68761ff25e028b'/>
<id>544e737dea5ad1a457f25dbddf68761ff25e028b</id>
<content type='text'>
Commit 2aa36604e824 ("PM: sleep: Avoid calling put_device() under
dpm_list_mtx") forgot to update the while () loop termination
condition to also break the loop if error is nonzero, which
causes the loop to become infinite if device_prepare() returns
an error for one device.

Add the missing !error check.

Fixes: 2aa36604e824 ("PM: sleep: Avoid calling put_device() under dpm_list_mtx")
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reported-by: Thomas Hellström &lt;thomas.hellstrom@linux.intel.com&gt;
Reviewed-by: Thomas Hellström &lt;thomas.hellstrom@linux.intel.com&gt;
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Cc: All applicable &lt;stable@vger.kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit 2aa36604e824 ("PM: sleep: Avoid calling put_device() under
dpm_list_mtx") forgot to update the while () loop termination
condition to also break the loop if error is nonzero, which
causes the loop to become infinite if device_prepare() returns
an error for one device.

Add the missing !error check.

Fixes: 2aa36604e824 ("PM: sleep: Avoid calling put_device() under dpm_list_mtx")
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reported-by: Thomas Hellström &lt;thomas.hellstrom@linux.intel.com&gt;
Reviewed-by: Thomas Hellström &lt;thomas.hellstrom@linux.intel.com&gt;
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Cc: All applicable &lt;stable@vger.kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM: sleep: Avoid calling put_device() under dpm_list_mtx</title>
<updated>2021-11-05T15:10:11+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2021-11-04T17:26:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2aa36604e8243698ff22bd5fef0dd0c6bb07ba92'/>
<id>2aa36604e8243698ff22bd5fef0dd0c6bb07ba92</id>
<content type='text'>
It is generally unsafe to call put_device() with dpm_list_mtx held,
because the given device's release routine may carry out an action
depending on that lock which then may deadlock, so modify the
system-wide suspend and resume of devices to always drop dpm_list_mtx
before calling put_device() (and adjust white space somewhat while
at it).

For instance, this prevents the following splat from showing up in
the kernel log after a system resume in certain configurations:

[ 3290.969514] ======================================================
[ 3290.969517] WARNING: possible circular locking dependency detected
[ 3290.969519] 5.15.0+ #2420 Tainted: G S
[ 3290.969523] ------------------------------------------------------
[ 3290.969525] systemd-sleep/4553 is trying to acquire lock:
[ 3290.969529] ffff888117ab1138 ((wq_completion)hci0#2){+.+.}-{0:0}, at: flush_workqueue+0x87/0x4a0
[ 3290.969554]
               but task is already holding lock:
[ 3290.969556] ffffffff8280fca8 (dpm_list_mtx){+.+.}-{3:3}, at: dpm_resume+0x12e/0x3e0
[ 3290.969571]
               which lock already depends on the new lock.

[ 3290.969573]
               the existing dependency chain (in reverse order) is:
[ 3290.969575]
               -&gt; #3 (dpm_list_mtx){+.+.}-{3:3}:
[ 3290.969583]        __mutex_lock+0x9d/0xa30
[ 3290.969591]        device_pm_add+0x2e/0xe0
[ 3290.969597]        device_add+0x4d5/0x8f0
[ 3290.969605]        hci_conn_add_sysfs+0x43/0xb0 [bluetooth]
[ 3290.969689]        hci_conn_complete_evt.isra.71+0x124/0x750 [bluetooth]
[ 3290.969747]        hci_event_packet+0xd6c/0x28a0 [bluetooth]
[ 3290.969798]        hci_rx_work+0x213/0x640 [bluetooth]
[ 3290.969842]        process_one_work+0x2aa/0x650
[ 3290.969851]        worker_thread+0x39/0x400
[ 3290.969859]        kthread+0x142/0x170
[ 3290.969865]        ret_from_fork+0x22/0x30
[ 3290.969872]
               -&gt; #2 (&amp;hdev-&gt;lock){+.+.}-{3:3}:
[ 3290.969881]        __mutex_lock+0x9d/0xa30
[ 3290.969887]        hci_event_packet+0xba/0x28a0 [bluetooth]
[ 3290.969935]        hci_rx_work+0x213/0x640 [bluetooth]
[ 3290.969978]        process_one_work+0x2aa/0x650
[ 3290.969985]        worker_thread+0x39/0x400
[ 3290.969993]        kthread+0x142/0x170
[ 3290.969999]        ret_from_fork+0x22/0x30
[ 3290.970004]
               -&gt; #1 ((work_completion)(&amp;hdev-&gt;rx_work)){+.+.}-{0:0}:
[ 3290.970013]        process_one_work+0x27d/0x650
[ 3290.970020]        worker_thread+0x39/0x400
[ 3290.970028]        kthread+0x142/0x170
[ 3290.970033]        ret_from_fork+0x22/0x30
[ 3290.970038]
               -&gt; #0 ((wq_completion)hci0#2){+.+.}-{0:0}:
[ 3290.970047]        __lock_acquire+0x15cb/0x1b50
[ 3290.970054]        lock_acquire+0x26c/0x300
[ 3290.970059]        flush_workqueue+0xae/0x4a0
[ 3290.970066]        drain_workqueue+0xa1/0x130
[ 3290.970073]        destroy_workqueue+0x34/0x1f0
[ 3290.970081]        hci_release_dev+0x49/0x180 [bluetooth]
[ 3290.970130]        bt_host_release+0x1d/0x30 [bluetooth]
[ 3290.970195]        device_release+0x33/0x90
[ 3290.970201]        kobject_release+0x63/0x160
[ 3290.970211]        dpm_resume+0x164/0x3e0
[ 3290.970215]        dpm_resume_end+0xd/0x20
[ 3290.970220]        suspend_devices_and_enter+0x1a4/0xba0
[ 3290.970229]        pm_suspend+0x26b/0x310
[ 3290.970236]        state_store+0x42/0x90
[ 3290.970243]        kernfs_fop_write_iter+0x135/0x1b0
[ 3290.970251]        new_sync_write+0x125/0x1c0
[ 3290.970257]        vfs_write+0x360/0x3c0
[ 3290.970263]        ksys_write+0xa7/0xe0
[ 3290.970269]        do_syscall_64+0x3a/0x80
[ 3290.970276]        entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 3290.970284]
               other info that might help us debug this:

[ 3290.970285] Chain exists of:
                 (wq_completion)hci0#2 --&gt; &amp;hdev-&gt;lock --&gt; dpm_list_mtx

[ 3290.970297]  Possible unsafe locking scenario:

[ 3290.970299]        CPU0                    CPU1
[ 3290.970300]        ----                    ----
[ 3290.970302]   lock(dpm_list_mtx);
[ 3290.970306]                                lock(&amp;hdev-&gt;lock);
[ 3290.970310]                                lock(dpm_list_mtx);
[ 3290.970314]   lock((wq_completion)hci0#2);
[ 3290.970319]
                *** DEADLOCK ***

[ 3290.970321] 7 locks held by systemd-sleep/4553:
[ 3290.970325]  #0: ffff888103bcd448 (sb_writers#4){.+.+}-{0:0}, at: ksys_write+0xa7/0xe0
[ 3290.970341]  #1: ffff888115a14488 (&amp;of-&gt;mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x103/0x1b0
[ 3290.970355]  #2: ffff888100f719e0 (kn-&gt;active#233){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x10c/0x1b0
[ 3290.970369]  #3: ffffffff82661048 (autosleep_lock){+.+.}-{3:3}, at: state_store+0x12/0x90
[ 3290.970384]  #4: ffffffff82658ac8 (system_transition_mutex){+.+.}-{3:3}, at: pm_suspend+0x9f/0x310
[ 3290.970399]  #5: ffffffff827f2a48 (acpi_scan_lock){+.+.}-{3:3}, at: acpi_suspend_begin+0x4c/0x80
[ 3290.970416]  #6: ffffffff8280fca8 (dpm_list_mtx){+.+.}-{3:3}, at: dpm_resume+0x12e/0x3e0
[ 3290.970428]
               stack backtrace:
[ 3290.970431] CPU: 3 PID: 4553 Comm: systemd-sleep Tainted: G S                5.15.0+ #2420
[ 3290.970438] Hardware name: Dell Inc. XPS 13 9380/0RYJWW, BIOS 1.5.0 06/03/2019
[ 3290.970441] Call Trace:
[ 3290.970446]  dump_stack_lvl+0x44/0x57
[ 3290.970454]  check_noncircular+0x105/0x120
[ 3290.970468]  ? __lock_acquire+0x15cb/0x1b50
[ 3290.970474]  __lock_acquire+0x15cb/0x1b50
[ 3290.970487]  lock_acquire+0x26c/0x300
[ 3290.970493]  ? flush_workqueue+0x87/0x4a0
[ 3290.970503]  ? __raw_spin_lock_init+0x3b/0x60
[ 3290.970510]  ? lockdep_init_map_type+0x58/0x240
[ 3290.970519]  flush_workqueue+0xae/0x4a0
[ 3290.970526]  ? flush_workqueue+0x87/0x4a0
[ 3290.970544]  ? drain_workqueue+0xa1/0x130
[ 3290.970552]  drain_workqueue+0xa1/0x130
[ 3290.970561]  destroy_workqueue+0x34/0x1f0
[ 3290.970572]  hci_release_dev+0x49/0x180 [bluetooth]
[ 3290.970624]  bt_host_release+0x1d/0x30 [bluetooth]
[ 3290.970687]  device_release+0x33/0x90
[ 3290.970695]  kobject_release+0x63/0x160
[ 3290.970705]  dpm_resume+0x164/0x3e0
[ 3290.970710]  ? dpm_resume_early+0x251/0x3b0
[ 3290.970718]  dpm_resume_end+0xd/0x20
[ 3290.970723]  suspend_devices_and_enter+0x1a4/0xba0
[ 3290.970737]  pm_suspend+0x26b/0x310
[ 3290.970746]  state_store+0x42/0x90
[ 3290.970755]  kernfs_fop_write_iter+0x135/0x1b0
[ 3290.970764]  new_sync_write+0x125/0x1c0
[ 3290.970777]  vfs_write+0x360/0x3c0
[ 3290.970785]  ksys_write+0xa7/0xe0
[ 3290.970794]  do_syscall_64+0x3a/0x80
[ 3290.970803]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 3290.970811] RIP: 0033:0x7f41b1328164
[ 3290.970819] Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 80 00 00 00 00 8b 05 4a d2 2c 00 48 63 ff 85 c0 75 13 b8 01 00 00 00 0f 05 &lt;48&gt; 3d 00 f0 ff ff 77 54 f3 c3 66 90 55 53 48 89 d5 48 89 f3 48 83
[ 3290.970824] RSP: 002b:00007ffe6ae21b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[ 3290.970831] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f41b1328164
[ 3290.970836] RDX: 0000000000000004 RSI: 000055965e651070 RDI: 0000000000000004
[ 3290.970839] RBP: 000055965e651070 R08: 000055965e64f390 R09: 00007f41b1e3d1c0
[ 3290.970843] R10: 000000000000000a R11: 0000000000000246 R12: 0000000000000004
[ 3290.970846] R13: 0000000000000001 R14: 000055965e64f2b0 R15: 0000000000000004

Cc: All applicable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
It is generally unsafe to call put_device() with dpm_list_mtx held,
because the given device's release routine may carry out an action
depending on that lock which then may deadlock, so modify the
system-wide suspend and resume of devices to always drop dpm_list_mtx
before calling put_device() (and adjust white space somewhat while
at it).

For instance, this prevents the following splat from showing up in
the kernel log after a system resume in certain configurations:

[ 3290.969514] ======================================================
[ 3290.969517] WARNING: possible circular locking dependency detected
[ 3290.969519] 5.15.0+ #2420 Tainted: G S
[ 3290.969523] ------------------------------------------------------
[ 3290.969525] systemd-sleep/4553 is trying to acquire lock:
[ 3290.969529] ffff888117ab1138 ((wq_completion)hci0#2){+.+.}-{0:0}, at: flush_workqueue+0x87/0x4a0
[ 3290.969554]
               but task is already holding lock:
[ 3290.969556] ffffffff8280fca8 (dpm_list_mtx){+.+.}-{3:3}, at: dpm_resume+0x12e/0x3e0
[ 3290.969571]
               which lock already depends on the new lock.

[ 3290.969573]
               the existing dependency chain (in reverse order) is:
[ 3290.969575]
               -&gt; #3 (dpm_list_mtx){+.+.}-{3:3}:
[ 3290.969583]        __mutex_lock+0x9d/0xa30
[ 3290.969591]        device_pm_add+0x2e/0xe0
[ 3290.969597]        device_add+0x4d5/0x8f0
[ 3290.969605]        hci_conn_add_sysfs+0x43/0xb0 [bluetooth]
[ 3290.969689]        hci_conn_complete_evt.isra.71+0x124/0x750 [bluetooth]
[ 3290.969747]        hci_event_packet+0xd6c/0x28a0 [bluetooth]
[ 3290.969798]        hci_rx_work+0x213/0x640 [bluetooth]
[ 3290.969842]        process_one_work+0x2aa/0x650
[ 3290.969851]        worker_thread+0x39/0x400
[ 3290.969859]        kthread+0x142/0x170
[ 3290.969865]        ret_from_fork+0x22/0x30
[ 3290.969872]
               -&gt; #2 (&amp;hdev-&gt;lock){+.+.}-{3:3}:
[ 3290.969881]        __mutex_lock+0x9d/0xa30
[ 3290.969887]        hci_event_packet+0xba/0x28a0 [bluetooth]
[ 3290.969935]        hci_rx_work+0x213/0x640 [bluetooth]
[ 3290.969978]        process_one_work+0x2aa/0x650
[ 3290.969985]        worker_thread+0x39/0x400
[ 3290.969993]        kthread+0x142/0x170
[ 3290.969999]        ret_from_fork+0x22/0x30
[ 3290.970004]
               -&gt; #1 ((work_completion)(&amp;hdev-&gt;rx_work)){+.+.}-{0:0}:
[ 3290.970013]        process_one_work+0x27d/0x650
[ 3290.970020]        worker_thread+0x39/0x400
[ 3290.970028]        kthread+0x142/0x170
[ 3290.970033]        ret_from_fork+0x22/0x30
[ 3290.970038]
               -&gt; #0 ((wq_completion)hci0#2){+.+.}-{0:0}:
[ 3290.970047]        __lock_acquire+0x15cb/0x1b50
[ 3290.970054]        lock_acquire+0x26c/0x300
[ 3290.970059]        flush_workqueue+0xae/0x4a0
[ 3290.970066]        drain_workqueue+0xa1/0x130
[ 3290.970073]        destroy_workqueue+0x34/0x1f0
[ 3290.970081]        hci_release_dev+0x49/0x180 [bluetooth]
[ 3290.970130]        bt_host_release+0x1d/0x30 [bluetooth]
[ 3290.970195]        device_release+0x33/0x90
[ 3290.970201]        kobject_release+0x63/0x160
[ 3290.970211]        dpm_resume+0x164/0x3e0
[ 3290.970215]        dpm_resume_end+0xd/0x20
[ 3290.970220]        suspend_devices_and_enter+0x1a4/0xba0
[ 3290.970229]        pm_suspend+0x26b/0x310
[ 3290.970236]        state_store+0x42/0x90
[ 3290.970243]        kernfs_fop_write_iter+0x135/0x1b0
[ 3290.970251]        new_sync_write+0x125/0x1c0
[ 3290.970257]        vfs_write+0x360/0x3c0
[ 3290.970263]        ksys_write+0xa7/0xe0
[ 3290.970269]        do_syscall_64+0x3a/0x80
[ 3290.970276]        entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 3290.970284]
               other info that might help us debug this:

[ 3290.970285] Chain exists of:
                 (wq_completion)hci0#2 --&gt; &amp;hdev-&gt;lock --&gt; dpm_list_mtx

[ 3290.970297]  Possible unsafe locking scenario:

[ 3290.970299]        CPU0                    CPU1
[ 3290.970300]        ----                    ----
[ 3290.970302]   lock(dpm_list_mtx);
[ 3290.970306]                                lock(&amp;hdev-&gt;lock);
[ 3290.970310]                                lock(dpm_list_mtx);
[ 3290.970314]   lock((wq_completion)hci0#2);
[ 3290.970319]
                *** DEADLOCK ***

[ 3290.970321] 7 locks held by systemd-sleep/4553:
[ 3290.970325]  #0: ffff888103bcd448 (sb_writers#4){.+.+}-{0:0}, at: ksys_write+0xa7/0xe0
[ 3290.970341]  #1: ffff888115a14488 (&amp;of-&gt;mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x103/0x1b0
[ 3290.970355]  #2: ffff888100f719e0 (kn-&gt;active#233){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x10c/0x1b0
[ 3290.970369]  #3: ffffffff82661048 (autosleep_lock){+.+.}-{3:3}, at: state_store+0x12/0x90
[ 3290.970384]  #4: ffffffff82658ac8 (system_transition_mutex){+.+.}-{3:3}, at: pm_suspend+0x9f/0x310
[ 3290.970399]  #5: ffffffff827f2a48 (acpi_scan_lock){+.+.}-{3:3}, at: acpi_suspend_begin+0x4c/0x80
[ 3290.970416]  #6: ffffffff8280fca8 (dpm_list_mtx){+.+.}-{3:3}, at: dpm_resume+0x12e/0x3e0
[ 3290.970428]
               stack backtrace:
[ 3290.970431] CPU: 3 PID: 4553 Comm: systemd-sleep Tainted: G S                5.15.0+ #2420
[ 3290.970438] Hardware name: Dell Inc. XPS 13 9380/0RYJWW, BIOS 1.5.0 06/03/2019
[ 3290.970441] Call Trace:
[ 3290.970446]  dump_stack_lvl+0x44/0x57
[ 3290.970454]  check_noncircular+0x105/0x120
[ 3290.970468]  ? __lock_acquire+0x15cb/0x1b50
[ 3290.970474]  __lock_acquire+0x15cb/0x1b50
[ 3290.970487]  lock_acquire+0x26c/0x300
[ 3290.970493]  ? flush_workqueue+0x87/0x4a0
[ 3290.970503]  ? __raw_spin_lock_init+0x3b/0x60
[ 3290.970510]  ? lockdep_init_map_type+0x58/0x240
[ 3290.970519]  flush_workqueue+0xae/0x4a0
[ 3290.970526]  ? flush_workqueue+0x87/0x4a0
[ 3290.970544]  ? drain_workqueue+0xa1/0x130
[ 3290.970552]  drain_workqueue+0xa1/0x130
[ 3290.970561]  destroy_workqueue+0x34/0x1f0
[ 3290.970572]  hci_release_dev+0x49/0x180 [bluetooth]
[ 3290.970624]  bt_host_release+0x1d/0x30 [bluetooth]
[ 3290.970687]  device_release+0x33/0x90
[ 3290.970695]  kobject_release+0x63/0x160
[ 3290.970705]  dpm_resume+0x164/0x3e0
[ 3290.970710]  ? dpm_resume_early+0x251/0x3b0
[ 3290.970718]  dpm_resume_end+0xd/0x20
[ 3290.970723]  suspend_devices_and_enter+0x1a4/0xba0
[ 3290.970737]  pm_suspend+0x26b/0x310
[ 3290.970746]  state_store+0x42/0x90
[ 3290.970755]  kernfs_fop_write_iter+0x135/0x1b0
[ 3290.970764]  new_sync_write+0x125/0x1c0
[ 3290.970777]  vfs_write+0x360/0x3c0
[ 3290.970785]  ksys_write+0xa7/0xe0
[ 3290.970794]  do_syscall_64+0x3a/0x80
[ 3290.970803]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 3290.970811] RIP: 0033:0x7f41b1328164
[ 3290.970819] Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 80 00 00 00 00 8b 05 4a d2 2c 00 48 63 ff 85 c0 75 13 b8 01 00 00 00 0f 05 &lt;48&gt; 3d 00 f0 ff ff 77 54 f3 c3 66 90 55 53 48 89 d5 48 89 f3 48 83
[ 3290.970824] RSP: 002b:00007ffe6ae21b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[ 3290.970831] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f41b1328164
[ 3290.970836] RDX: 0000000000000004 RSI: 000055965e651070 RDI: 0000000000000004
[ 3290.970839] RBP: 000055965e651070 R08: 000055965e64f390 R09: 00007f41b1e3d1c0
[ 3290.970843] R10: 000000000000000a R11: 0000000000000246 R12: 0000000000000004
[ 3290.970846] R13: 0000000000000001 R14: 000055965e64f2b0 R15: 0000000000000004

Cc: All applicable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM: sleep: Fix runtime PM based cpuidle support</title>
<updated>2021-11-04T18:45:38+00:00</updated>
<author>
<name>Ulf Hansson</name>
<email>ulf.hansson@linaro.org</email>
</author>
<published>2021-10-29T12:38:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a2bd7be12b9edab5736a9a95bceccfbdf7520fdd'/>
<id>a2bd7be12b9edab5736a9a95bceccfbdf7520fdd</id>
<content type='text'>
In the cpuidle-psci case, runtime PM in combination with the generic PM
domain (genpd), may be used when entering/exiting a shared idlestate. More
precisely, genpd relies on runtime PM to be enabled for the attached device
(in this case it belongs to a CPU), to properly manage the reference
counting of its PM domain.

This works fine most of the time, but during system suspend in
dpm_suspend_late(), the PM core disables runtime PM for all devices. Beyond
this point, calls to pm_runtime_get_sync() to runtime resume a device may
fail and therefore it could also mess up the reference counting in genpd.

To fix this problem, let's call wake_up_all_idle_cpus() in
dpm_suspend_late(), prior to disabling runtime PM. In this way a device
that belongs to a CPU, becomes runtime resumed through cpuidle-psci and
stays like that, because the runtime PM usage count has been bumped in
device_prepare().

Diagnosed-by: Maulik Shah &lt;mkshah@codeaurora.org&gt;
Suggested-by: Rafael J. Wysocki &lt;rafael@kernel.org&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In the cpuidle-psci case, runtime PM in combination with the generic PM
domain (genpd), may be used when entering/exiting a shared idlestate. More
precisely, genpd relies on runtime PM to be enabled for the attached device
(in this case it belongs to a CPU), to properly manage the reference
counting of its PM domain.

This works fine most of the time, but during system suspend in
dpm_suspend_late(), the PM core disables runtime PM for all devices. Beyond
this point, calls to pm_runtime_get_sync() to runtime resume a device may
fail and therefore it could also mess up the reference counting in genpd.

To fix this problem, let's call wake_up_all_idle_cpus() in
dpm_suspend_late(), prior to disabling runtime PM. In this way a device
that belongs to a CPU, becomes runtime resumed through cpuidle-psci and
stays like that, because the runtime PM usage count has been bumped in
device_prepare().

Diagnosed-by: Maulik Shah &lt;mkshah@codeaurora.org&gt;
Suggested-by: Rafael J. Wysocki &lt;rafael@kernel.org&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'pm-sleep'</title>
<updated>2021-11-02T18:11:49+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2021-11-02T18:11:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b62b306469b36fae7030c0ad4ffa11de0c9b9957'/>
<id>b62b306469b36fae7030c0ad4ffa11de0c9b9957</id>
<content type='text'>
Merge updates related to system sleep for 5.16-rc1:

 - Clean up hib_wait_io() (Falla Coulibaly).

 - Fix sparse warnings in hibernation-related code (Anders Roxell).

 - Use vzalloc() and kzalloc() instead of their open-coded
   equivalents in hibernation-related code (Cai Huoqing).

 - Prevent user space from crashing the kernel by attempting to
   restore the system state from a swap partition in use (Ye Bin).

 - Do not let "syscore" devices runtime-suspend during system PM
   transitions (Rafael Wysocki).

 - Do not pause cpuidle in the suspend-to-idle path (Rafael Wysocki).

 - Pause cpuidle later and resume it earlier during system PM
   transitions (Rafael Wysocki).

 - Make system suspend code use valid_state() consistently (Rafael
   Wysocki).

 - Add support for enabling wakeup IRQs after invoking the
   -&gt;runtime_suspend() callback and make two drivers use it (Chunfeng
   Yun).

* pm-sleep:
  usb: mtu3: enable wake-up interrupt after runtime_suspend called
  usb: xhci-mtk: enable wake-up interrupt after runtime_suspend called
  PM / wakeirq: support enabling wake-up irq after runtime_suspend called
  PM: suspend: Use valid_state() consistently
  PM: sleep: Pause cpuidle later and resume it earlier during system transitions
  PM: suspend: Do not pause cpuidle in the suspend-to-idle path
  PM: sleep: Do not let "syscore" devices runtime-suspend during system transitions
  PM: hibernate: Get block device exclusively in swsusp_check()
  PM: hibernate: swap: Use vzalloc() and kzalloc()
  PM: hibernate: fix sparse warnings
  Revert "PM: sleep: Do not assume that "mem" is always present"
  PM: hibernate: Remove blk_status_to_errno in hib_wait_io
  PM: sleep: Do not assume that "mem" is always present
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Merge updates related to system sleep for 5.16-rc1:

 - Clean up hib_wait_io() (Falla Coulibaly).

 - Fix sparse warnings in hibernation-related code (Anders Roxell).

 - Use vzalloc() and kzalloc() instead of their open-coded
   equivalents in hibernation-related code (Cai Huoqing).

 - Prevent user space from crashing the kernel by attempting to
   restore the system state from a swap partition in use (Ye Bin).

 - Do not let "syscore" devices runtime-suspend during system PM
   transitions (Rafael Wysocki).

 - Do not pause cpuidle in the suspend-to-idle path (Rafael Wysocki).

 - Pause cpuidle later and resume it earlier during system PM
   transitions (Rafael Wysocki).

 - Make system suspend code use valid_state() consistently (Rafael
   Wysocki).

 - Add support for enabling wakeup IRQs after invoking the
   -&gt;runtime_suspend() callback and make two drivers use it (Chunfeng
   Yun).

* pm-sleep:
  usb: mtu3: enable wake-up interrupt after runtime_suspend called
  usb: xhci-mtk: enable wake-up interrupt after runtime_suspend called
  PM / wakeirq: support enabling wake-up irq after runtime_suspend called
  PM: suspend: Use valid_state() consistently
  PM: sleep: Pause cpuidle later and resume it earlier during system transitions
  PM: suspend: Do not pause cpuidle in the suspend-to-idle path
  PM: sleep: Do not let "syscore" devices runtime-suspend during system transitions
  PM: hibernate: Get block device exclusively in swsusp_check()
  PM: hibernate: swap: Use vzalloc() and kzalloc()
  PM: hibernate: fix sparse warnings
  Revert "PM: sleep: Do not assume that "mem" is always present"
  PM: hibernate: Remove blk_status_to_errno in hib_wait_io
  PM: sleep: Do not assume that "mem" is always present
</pre>
</div>
</content>
</entry>
<entry>
<title>PM / wakeirq: support enabling wake-up irq after runtime_suspend called</title>
<updated>2021-10-27T18:49:32+00:00</updated>
<author>
<name>Chunfeng Yun</name>
<email>chunfeng.yun@mediatek.com</email>
</author>
<published>2021-10-25T07:01:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=259714100d98b50bf04d36a21bf50ca8b829fc11'/>
<id>259714100d98b50bf04d36a21bf50ca8b829fc11</id>
<content type='text'>
When the dedicated wake IRQ is level trigger, and it uses the
device's low-power status as the wakeup source, that means if the
device is not in low-power state, the wake IRQ will be triggered
if enabled; For this case, need enable the wake IRQ after running
the device's -&gt;runtime_suspend() which make it enter low-power state.

e.g.
Assume the wake IRQ is a low level trigger type, and the wakeup
signal comes from the low-power status of the device.
The wakeup signal is low level at running time (0), and becomes
high level when the device enters low-power state (runtime_suspend
(1) is called), a wakeup event at (2) make the device exit low-power
state, then the wakeup signal also becomes low level.

                ------------------
               |           ^     ^|
----------------           |     | --------------
 |&lt;---(0)---&gt;|&lt;--(1)--|   (3)   (2)    (4)

if enable the wake IRQ before running runtime_suspend during (0),
a wake IRQ will arise, it causes resume immediately;
it works if enable wake IRQ ( e.g. at (3) or (4)) after running
-&gt;runtime_suspend().

This patch introduces a new status WAKE_IRQ_DEDICATED_REVERSE to
optionally support enabling wake IRQ after running -&gt;runtime_suspend().

Suggested-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Chunfeng Yun &lt;chunfeng.yun@mediatek.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When the dedicated wake IRQ is level trigger, and it uses the
device's low-power status as the wakeup source, that means if the
device is not in low-power state, the wake IRQ will be triggered
if enabled; For this case, need enable the wake IRQ after running
the device's -&gt;runtime_suspend() which make it enter low-power state.

e.g.
Assume the wake IRQ is a low level trigger type, and the wakeup
signal comes from the low-power status of the device.
The wakeup signal is low level at running time (0), and becomes
high level when the device enters low-power state (runtime_suspend
(1) is called), a wakeup event at (2) make the device exit low-power
state, then the wakeup signal also becomes low level.

                ------------------
               |           ^     ^|
----------------           |     | --------------
 |&lt;---(0)---&gt;|&lt;--(1)--|   (3)   (2)    (4)

if enable the wake IRQ before running runtime_suspend during (0),
a wake IRQ will arise, it causes resume immediately;
it works if enable wake IRQ ( e.g. at (3) or (4)) after running
-&gt;runtime_suspend().

This patch introduces a new status WAKE_IRQ_DEDICATED_REVERSE to
optionally support enabling wake IRQ after running -&gt;runtime_suspend().

Suggested-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Chunfeng Yun &lt;chunfeng.yun@mediatek.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM: sleep: Pause cpuidle later and resume it earlier during system transitions</title>
<updated>2021-10-26T13:52:07+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2021-10-22T16:07:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=23f62d7ab25bd1a7dbbb89cfcd429df7735855af'/>
<id>23f62d7ab25bd1a7dbbb89cfcd429df7735855af</id>
<content type='text'>
Commit 8651f97bd951 ("PM / cpuidle: System resume hang fix with
cpuidle") that introduced cpuidle pausing during system suspend
did that to work around a platform firmware issue causing systems
to hang during resume if CPUs were allowed to enter idle states
in the system suspend and resume code paths.

However, pausing cpuidle before the last phase of suspending
devices is the source of an otherwise arbitrary difference between
the suspend-to-idle path and other system suspend variants, so it is
cleaner to do that later, before taking secondary CPUs offline (it
is still safer to take secondary CPUs offline with cpuidle paused,
though).

Modify the code accordingly, but in order to avoid code duplication,
introduce new wrapper functions, pm_sleep_disable_secondary_cpus()
and pm_sleep_enable_secondary_cpus(), to combine cpuidle_pause()
and cpuidle_resume(), respectively, with the handling of secondary
CPUs during system-wide transitions to sleep states.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Tested-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit 8651f97bd951 ("PM / cpuidle: System resume hang fix with
cpuidle") that introduced cpuidle pausing during system suspend
did that to work around a platform firmware issue causing systems
to hang during resume if CPUs were allowed to enter idle states
in the system suspend and resume code paths.

However, pausing cpuidle before the last phase of suspending
devices is the source of an otherwise arbitrary difference between
the suspend-to-idle path and other system suspend variants, so it is
cleaner to do that later, before taking secondary CPUs offline (it
is still safer to take secondary CPUs offline with cpuidle paused,
though).

Modify the code accordingly, but in order to avoid code duplication,
introduce new wrapper functions, pm_sleep_disable_secondary_cpus()
and pm_sleep_enable_secondary_cpus(), to combine cpuidle_pause()
and cpuidle_resume(), respectively, with the handling of secondary
CPUs during system-wide transitions to sleep states.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Tested-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM: suspend: Do not pause cpuidle in the suspend-to-idle path</title>
<updated>2021-10-26T13:52:07+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2021-10-22T16:04:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8d89835b0467b7e618c1c93603c1aff85a0c3c66'/>
<id>8d89835b0467b7e618c1c93603c1aff85a0c3c66</id>
<content type='text'>
It is pointless to pause cpuidle in the suspend-to-idle path,
because it is going to be resumed in the same path later and
pausing it does not serve any particular purpose in that case.

Rework the code to avoid doing that.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Tested-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
It is pointless to pause cpuidle in the suspend-to-idle path,
because it is going to be resumed in the same path later and
pausing it does not serve any particular purpose in that case.

Rework the code to avoid doing that.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Tested-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM: sleep: Do not let "syscore" devices runtime-suspend during system transitions</title>
<updated>2021-10-22T16:09:58+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2021-10-22T12:58:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=928265e3601cde78c7e0a3e518a93b27defed3b1'/>
<id>928265e3601cde78c7e0a3e518a93b27defed3b1</id>
<content type='text'>
There is no reason to allow "syscore" devices to runtime-suspend
during system-wide PM transitions, because they are subject to the
same possible failure modes as any other devices in that respect.

Accordingly, change device_prepare() and device_complete() to call
pm_runtime_get_noresume() and pm_runtime_put(), respectively, for
"syscore" devices too.

Fixes: 057d51a1268f ("Merge branch 'pm-sleep'")
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Cc: 3.10+ &lt;stable@vger.kernel.org&gt; # 3.10+
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There is no reason to allow "syscore" devices to runtime-suspend
during system-wide PM transitions, because they are subject to the
same possible failure modes as any other devices in that respect.

Accordingly, change device_prepare() and device_complete() to call
pm_runtime_get_noresume() and pm_runtime_put(), respectively, for
"syscore" devices too.

Fixes: 057d51a1268f ("Merge branch 'pm-sleep'")
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Cc: 3.10+ &lt;stable@vger.kernel.org&gt; # 3.10+
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-linus-5.15b-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip</title>
<updated>2021-09-17T15:31:49+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-09-17T15:31:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c6460daea23dcd160f2dc497c64b4c882ea1de69'/>
<id>c6460daea23dcd160f2dc497c64b4c882ea1de69</id>
<content type='text'>
Pull xen fixes from Juergen Gross:

 - The first hunk of a Xen swiotlb fixup series fixing multiple minor
   issues and doing some small cleanups

 - Some further Xen related fixes avoiding WARN() splats when running as
   Xen guests or dom0

 - A Kconfig fix allowing the pvcalls frontend to be built as a module

* tag 'for-linus-5.15b-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  swiotlb-xen: drop DEFAULT_NSLABS
  swiotlb-xen: arrange to have buffer info logged
  swiotlb-xen: drop leftover __ref
  swiotlb-xen: limit init retries
  swiotlb-xen: suppress certain init retries
  swiotlb-xen: maintain slab count properly
  swiotlb-xen: fix late init retry
  swiotlb-xen: avoid double free
  xen/pvcalls: backend can be a module
  xen: fix usage of pmd_populate in mremap for pv guests
  xen: reset legacy rtc flag for PV domU
  PM: base: power: don't try to use non-existing RTC for storing data
  xen/balloon: use a kernel thread instead a workqueue
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull xen fixes from Juergen Gross:

 - The first hunk of a Xen swiotlb fixup series fixing multiple minor
   issues and doing some small cleanups

 - Some further Xen related fixes avoiding WARN() splats when running as
   Xen guests or dom0

 - A Kconfig fix allowing the pvcalls frontend to be built as a module

* tag 'for-linus-5.15b-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  swiotlb-xen: drop DEFAULT_NSLABS
  swiotlb-xen: arrange to have buffer info logged
  swiotlb-xen: drop leftover __ref
  swiotlb-xen: limit init retries
  swiotlb-xen: suppress certain init retries
  swiotlb-xen: maintain slab count properly
  swiotlb-xen: fix late init retry
  swiotlb-xen: avoid double free
  xen/pvcalls: backend can be a module
  xen: fix usage of pmd_populate in mremap for pv guests
  xen: reset legacy rtc flag for PV domU
  PM: base: power: don't try to use non-existing RTC for storing data
  xen/balloon: use a kernel thread instead a workqueue
</pre>
</div>
</content>
</entry>
<entry>
<title>PM: base: power: don't try to use non-existing RTC for storing data</title>
<updated>2021-09-14T07:56:20+00:00</updated>
<author>
<name>Juergen Gross</name>
<email>jgross@suse.com</email>
</author>
<published>2021-09-03T08:49:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0560204b360a332c321124dbc5cdfd3364533a74'/>
<id>0560204b360a332c321124dbc5cdfd3364533a74</id>
<content type='text'>
If there is no legacy RTC device, don't try to use it for storing trace
data across suspend/resume.

Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
Reviewed-by: Rafael J. Wysocki &lt;rafael@kernel.org&gt;
Link: https://lore.kernel.org/r/20210903084937.19392-2-jgross@suse.com
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If there is no legacy RTC device, don't try to use it for storing trace
data across suspend/resume.

Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
Reviewed-by: Rafael J. Wysocki &lt;rafael@kernel.org&gt;
Link: https://lore.kernel.org/r/20210903084937.19392-2-jgross@suse.com
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
