<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/kernel/power, branch v6.0-rc6</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>Merge tag 'char-misc-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc</title>
<updated>2022-08-04T18:05:48+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-08-04T18:05:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=228dfe98a313f6b6bff5da8b2c5e650e297ebf1a'/>
<id>228dfe98a313f6b6bff5da8b2c5e650e297ebf1a</id>
<content type='text'>
Pull char / misc driver updates from Greg KH:
 "Here is the large set of char and misc and other driver subsystem
  changes for 6.0-rc1.

  Highlights include:

   - large set of IIO driver updates, additions, and cleanups

   - new habanalabs device support added (loads of register maps much
     like GPUs have)

   - soundwire driver updates

   - phy driver updates

   - slimbus driver updates

   - tiny virt driver fixes and updates

   - misc driver fixes and updates

   - interconnect driver updates

   - hwtracing driver updates

   - fpga driver updates

   - extcon driver updates

   - firmware driver updates

   - counter driver update

   - mhi driver fixes and updates

   - binder driver fixes and updates

   - speakup driver fixes

  All of these have been in linux-next for a while without any reported
  problems"

* tag 'char-misc-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (634 commits)
  drivers: lkdtm: fix clang -Wformat warning
  char: remove VR41XX related char driver
  misc: Mark MICROCODE_MINOR unused
  spmi: trace: fix stack-out-of-bound access in SPMI tracing functions
  dt-bindings: iio: adc: Add compatible for MT8188
  iio: light: isl29028: Fix the warning in isl29028_remove()
  iio: accel: sca3300: Extend the trigger buffer from 16 to 32 bytes
  iio: fix iio_format_avail_range() printing for none IIO_VAL_INT
  iio: adc: max1027: unlock on error path in max1027_read_single_value()
  iio: proximity: sx9324: add empty line in front of bullet list
  iio: magnetometer: hmc5843: Remove duplicate 'the'
  iio: magn: yas530: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr() macros
  iio: magnetometer: ak8974: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr() macros
  iio: light: veml6030: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr() macros
  iio: light: vcnl4035: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr() macros
  iio: light: vcnl4000: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr() macros
  iio: light: tsl2591: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr()
  iio: light: tsl2583: Use DEFINE_RUNTIME_DEV_PM_OPS and pm_ptr()
  iio: light: isl29028: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr()
  iio: light: gp2ap002: Switch to DEFINE_RUNTIME_DEV_PM_OPS and pm_ptr()
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull char / misc driver updates from Greg KH:
 "Here is the large set of char and misc and other driver subsystem
  changes for 6.0-rc1.

  Highlights include:

   - large set of IIO driver updates, additions, and cleanups

   - new habanalabs device support added (loads of register maps much
     like GPUs have)

   - soundwire driver updates

   - phy driver updates

   - slimbus driver updates

   - tiny virt driver fixes and updates

   - misc driver fixes and updates

   - interconnect driver updates

   - hwtracing driver updates

   - fpga driver updates

   - extcon driver updates

   - firmware driver updates

   - counter driver update

   - mhi driver fixes and updates

   - binder driver fixes and updates

   - speakup driver fixes

  All of these have been in linux-next for a while without any reported
  problems"

* tag 'char-misc-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (634 commits)
  drivers: lkdtm: fix clang -Wformat warning
  char: remove VR41XX related char driver
  misc: Mark MICROCODE_MINOR unused
  spmi: trace: fix stack-out-of-bound access in SPMI tracing functions
  dt-bindings: iio: adc: Add compatible for MT8188
  iio: light: isl29028: Fix the warning in isl29028_remove()
  iio: accel: sca3300: Extend the trigger buffer from 16 to 32 bytes
  iio: fix iio_format_avail_range() printing for none IIO_VAL_INT
  iio: adc: max1027: unlock on error path in max1027_read_single_value()
  iio: proximity: sx9324: add empty line in front of bullet list
  iio: magnetometer: hmc5843: Remove duplicate 'the'
  iio: magn: yas530: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr() macros
  iio: magnetometer: ak8974: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr() macros
  iio: light: veml6030: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr() macros
  iio: light: vcnl4035: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr() macros
  iio: light: vcnl4000: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr() macros
  iio: light: tsl2591: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr()
  iio: light: tsl2583: Use DEFINE_RUNTIME_DEV_PM_OPS and pm_ptr()
  iio: light: isl29028: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr()
  iio: light: gp2ap002: Switch to DEFINE_RUNTIME_DEV_PM_OPS and pm_ptr()
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-5.20/block-2022-07-29' of git://git.kernel.dk/linux-block</title>
<updated>2022-08-02T20:46:35+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-08-02T20:46:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c013d0af81f60cc7dbe357c4e2a925fb6738dbfe'/>
<id>c013d0af81f60cc7dbe357c4e2a925fb6738dbfe</id>
<content type='text'>
Pull block updates from Jens Axboe:

 - Improve the type checking of request flags (Bart)

 - Ensure queue mapping for a single queues always picks the right queue
   (Bart)

 - Sanitize the io priority handling (Jan)

 - rq-qos race fix (Jinke)

 - Reserved tags handling improvements (John)

 - Separate memory alignment from file/disk offset aligment for O_DIRECT
   (Keith)

 - Add new ublk driver, userspace block driver using io_uring for
   communication with the userspace backend (Ming)

 - Use try_cmpxchg() to cleanup the code in various spots (Uros)

 - Finally remove bdevname() (Christoph)

 - Clean up the zoned device handling (Christoph)

 - Clean up independent access range support (Christoph)

 - Clean up and improve block sysfs handling (Christoph)

 - Clean up and improve teardown of block devices.

   This turns the usual two step process into something that is simpler
   to implement and handle in block drivers (Christoph)

 - Clean up chunk size handling (Christoph)

 - Misc cleanups and fixes (Bart, Bo, Dan, GuoYong, Jason, Keith, Liu,
   Ming, Sebastian, Yang, Ying)

* tag 'for-5.20/block-2022-07-29' of git://git.kernel.dk/linux-block: (178 commits)
  ublk_drv: fix double shift bug
  ublk_drv: make sure that correct flags(features) returned to userspace
  ublk_drv: fix error handling of ublk_add_dev
  ublk_drv: fix lockdep warning
  block: remove __blk_get_queue
  block: call blk_mq_exit_queue from disk_release for never added disks
  blk-mq: fix error handling in __blk_mq_alloc_disk
  ublk: defer disk allocation
  ublk: rewrite ublk_ctrl_get_queue_affinity to not rely on hctx-&gt;cpumask
  ublk: fold __ublk_create_dev into ublk_ctrl_add_dev
  ublk: cleanup ublk_ctrl_uring_cmd
  ublk: simplify ublk_ch_open and ublk_ch_release
  ublk: remove the empty open and release block device operations
  ublk: remove UBLK_IO_F_PREFLUSH
  ublk: add a MAINTAINERS entry
  block: don't allow the same type rq_qos add more than once
  mmc: fix disk/queue leak in case of adding disk failure
  ublk_drv: fix an IS_ERR() vs NULL check
  ublk: remove UBLK_IO_F_INTEGRITY
  ublk_drv: remove unneeded semicolon
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull block updates from Jens Axboe:

 - Improve the type checking of request flags (Bart)

 - Ensure queue mapping for a single queues always picks the right queue
   (Bart)

 - Sanitize the io priority handling (Jan)

 - rq-qos race fix (Jinke)

 - Reserved tags handling improvements (John)

 - Separate memory alignment from file/disk offset aligment for O_DIRECT
   (Keith)

 - Add new ublk driver, userspace block driver using io_uring for
   communication with the userspace backend (Ming)

 - Use try_cmpxchg() to cleanup the code in various spots (Uros)

 - Finally remove bdevname() (Christoph)

 - Clean up the zoned device handling (Christoph)

 - Clean up independent access range support (Christoph)

 - Clean up and improve block sysfs handling (Christoph)

 - Clean up and improve teardown of block devices.

   This turns the usual two step process into something that is simpler
   to implement and handle in block drivers (Christoph)

 - Clean up chunk size handling (Christoph)

 - Misc cleanups and fixes (Bart, Bo, Dan, GuoYong, Jason, Keith, Liu,
   Ming, Sebastian, Yang, Ying)

* tag 'for-5.20/block-2022-07-29' of git://git.kernel.dk/linux-block: (178 commits)
  ublk_drv: fix double shift bug
  ublk_drv: make sure that correct flags(features) returned to userspace
  ublk_drv: fix error handling of ublk_add_dev
  ublk_drv: fix lockdep warning
  block: remove __blk_get_queue
  block: call blk_mq_exit_queue from disk_release for never added disks
  blk-mq: fix error handling in __blk_mq_alloc_disk
  ublk: defer disk allocation
  ublk: rewrite ublk_ctrl_get_queue_affinity to not rely on hctx-&gt;cpumask
  ublk: fold __ublk_create_dev into ublk_ctrl_add_dev
  ublk: cleanup ublk_ctrl_uring_cmd
  ublk: simplify ublk_ch_open and ublk_ch_release
  ublk: remove the empty open and release block device operations
  ublk: remove UBLK_IO_F_PREFLUSH
  ublk: add a MAINTAINERS entry
  block: don't allow the same type rq_qos add more than once
  mmc: fix disk/queue leak in case of adding disk failure
  ublk_drv: fix an IS_ERR() vs NULL check
  ublk: remove UBLK_IO_F_INTEGRITY
  ublk_drv: remove unneeded semicolon
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branches 'pm-devfreq', 'pm-qos', 'pm-tools' and 'pm-docs'</title>
<updated>2022-07-29T17:46:00+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2022-07-29T17:46:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=aa727b7b4b67dba2a6cfebdd98767c455c2b3d69'/>
<id>aa727b7b4b67dba2a6cfebdd98767c455c2b3d69</id>
<content type='text'>
Merge devfreq changes, PM QoS change, and power management tools and
documentation changes for v5.20-rc1:

 - Add new devfreq driver for Mediatek CCI (Cache Coherent
   Interconnect) (Johnson Wang).

 - Convert the Samsung Exynos SoC Bus bindings to DT schema of
   exynos-bus.c (Krzysztof Kozlowski).

 - Address kernel-doc warnings by adding the description for unused
   fucntion parameters in devfreq core (Mauro Carvalho Chehab).

 - Use NULL to pass a null pointer rather than zero according to the
   function propotype in imx-bus.c (Colin Ian King).

 - Print error message instead of error interger value in
   tegra30-devfreq.c (Dmitry Osipenko).

 - Add checks to prevent setting negative frequency QoS limits for
   CPUs (Shivnandan Kumar).

 - Update the pm-graph suite of utilities to the latest revision 5.9
   including multiple improvements (Todd Brandt).

 - Drop pme_interrupt reference from the PCI power management
   documentation (Mario Limonciello).

* pm-devfreq:
  PM / devfreq: tegra30: Add error message for devm_devfreq_add_device()
  PM / devfreq: imx-bus: use NULL to pass a null pointer rather than zero
  PM / devfreq: shut up kernel-doc warnings
  dt-bindings: interconnect: samsung,exynos-bus: convert to dtschema
  PM / devfreq: mediatek: Introduce MediaTek CCI devfreq driver
  dt-bindings: interconnect: Add MediaTek CCI dt-bindings

* pm-qos:
  PM: QoS: Add check to make sure CPU freq is non-negative

* pm-tools:
  pm-graph v5.9

* pm-docs:
  Documentation: PM: Drop pme_interrupt reference
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Merge devfreq changes, PM QoS change, and power management tools and
documentation changes for v5.20-rc1:

 - Add new devfreq driver for Mediatek CCI (Cache Coherent
   Interconnect) (Johnson Wang).

 - Convert the Samsung Exynos SoC Bus bindings to DT schema of
   exynos-bus.c (Krzysztof Kozlowski).

 - Address kernel-doc warnings by adding the description for unused
   fucntion parameters in devfreq core (Mauro Carvalho Chehab).

 - Use NULL to pass a null pointer rather than zero according to the
   function propotype in imx-bus.c (Colin Ian King).

 - Print error message instead of error interger value in
   tegra30-devfreq.c (Dmitry Osipenko).

 - Add checks to prevent setting negative frequency QoS limits for
   CPUs (Shivnandan Kumar).

 - Update the pm-graph suite of utilities to the latest revision 5.9
   including multiple improvements (Todd Brandt).

 - Drop pme_interrupt reference from the PCI power management
   documentation (Mario Limonciello).

* pm-devfreq:
  PM / devfreq: tegra30: Add error message for devm_devfreq_add_device()
  PM / devfreq: imx-bus: use NULL to pass a null pointer rather than zero
  PM / devfreq: shut up kernel-doc warnings
  dt-bindings: interconnect: samsung,exynos-bus: convert to dtschema
  PM / devfreq: mediatek: Introduce MediaTek CCI devfreq driver
  dt-bindings: interconnect: Add MediaTek CCI dt-bindings

* pm-qos:
  PM: QoS: Add check to make sure CPU freq is non-negative

* pm-tools:
  pm-graph v5.9

* pm-docs:
  Documentation: PM: Drop pme_interrupt reference
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branches 'pm-core', 'pm-sleep', 'powercap', 'pm-domains' and 'pm-em'</title>
<updated>2022-07-29T17:33:13+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2022-07-29T17:33:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=954a83fc60c805f138db26747645710f243a9939'/>
<id>954a83fc60c805f138db26747645710f243a9939</id>
<content type='text'>
Merge core device power management changes for v5.20-rc1:

 - Extend support for wakeirq to callback wrappers used during system
   suspend and resume (Ulf Hansson).

 - Defer waiting for device probe before loading a hibernation image
   till the first actual device access to avoid possible deadlocks
   reported by syzbot (Tetsuo Handa).

 - Unify device_init_wakeup() for PM_SLEEP and !PM_SLEEP (Bjorn
   Helgaas).

 - Add Raptor Lake-P to the list of processors supported by the Intel
   RAPL driver (George D Sworo).

 - Add Alder Lake-N and Raptor Lake-P to the list of processors for
   which Power Limit4 is supported in the Intel RAPL driver (Sumeet
   Pawnikar).

 - Make pm_genpd_remove() check genpd_debugfs_dir against NULL before
   attempting to remove it (Hsin-Yi Wang).

 - Change the Energy Model code to represent power in micro-Watts and
   adjust its users accordingly (Lukasz Luba).

* pm-core:
  PM: runtime: Extend support for wakeirq for force_suspend|resume

* pm-sleep:
  PM: hibernate: defer device probing when resuming from hibernation
  PM: wakeup: Unify device_init_wakeup() for PM_SLEEP and !PM_SLEEP

* powercap:
  powercap: RAPL: Add Power Limit4 support for Alder Lake-N and Raptor Lake-P
  powercap: intel_rapl: Add support for RAPTORLAKE_P

* pm-domains:
  PM: domains: Ensure genpd_debugfs_dir exists before remove

* pm-em:
  cpufreq: scmi: Support the power scale in micro-Watts in SCMI v3.1
  firmware: arm_scmi: Get detailed power scale from perf
  Documentation: EM: Switch to micro-Watts scale
  PM: EM: convert power field to micro-Watts precision and align drivers
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Merge core device power management changes for v5.20-rc1:

 - Extend support for wakeirq to callback wrappers used during system
   suspend and resume (Ulf Hansson).

 - Defer waiting for device probe before loading a hibernation image
   till the first actual device access to avoid possible deadlocks
   reported by syzbot (Tetsuo Handa).

 - Unify device_init_wakeup() for PM_SLEEP and !PM_SLEEP (Bjorn
   Helgaas).

 - Add Raptor Lake-P to the list of processors supported by the Intel
   RAPL driver (George D Sworo).

 - Add Alder Lake-N and Raptor Lake-P to the list of processors for
   which Power Limit4 is supported in the Intel RAPL driver (Sumeet
   Pawnikar).

 - Make pm_genpd_remove() check genpd_debugfs_dir against NULL before
   attempting to remove it (Hsin-Yi Wang).

 - Change the Energy Model code to represent power in micro-Watts and
   adjust its users accordingly (Lukasz Luba).

* pm-core:
  PM: runtime: Extend support for wakeirq for force_suspend|resume

* pm-sleep:
  PM: hibernate: defer device probing when resuming from hibernation
  PM: wakeup: Unify device_init_wakeup() for PM_SLEEP and !PM_SLEEP

* powercap:
  powercap: RAPL: Add Power Limit4 support for Alder Lake-N and Raptor Lake-P
  powercap: intel_rapl: Add support for RAPTORLAKE_P

* pm-domains:
  PM: domains: Ensure genpd_debugfs_dir exists before remove

* pm-em:
  cpufreq: scmi: Support the power scale in micro-Watts in SCMI v3.1
  firmware: arm_scmi: Get detailed power scale from perf
  Documentation: EM: Switch to micro-Watts scale
  PM: EM: convert power field to micro-Watts precision and align drivers
</pre>
</div>
</content>
</entry>
<entry>
<title>PM: QoS: Add check to make sure CPU freq is non-negative</title>
<updated>2022-07-26T18:48:33+00:00</updated>
<author>
<name>Shivnandan Kumar</name>
<email>quic_kshivnan@quicinc.com</email>
</author>
<published>2022-07-15T12:25:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8d36694245f2aec17f03a5e0b2797953d2e36704'/>
<id>8d36694245f2aec17f03a5e0b2797953d2e36704</id>
<content type='text'>
CPU frequency should never be negative.

If some client driver calls freq_qos_update_request with a
negative value which will be very high in absolute terms,
then frequency QoS sets max CPU freq at fmax as it considers
it's absolute value but it will add plist node with negative
priority.

plist node has priority from INT_MIN (highest) to INT_MAX(lowest).
Once priority is set as negative, another client will not be able
to reduce CPU frequency.

Adding check to make sure CPU freq is non-negative will fix
this problem.

Signed-off-by: Shivnandan Kumar &lt;quic_kshivnan@quicinc.com&gt;
[ rjw: Changelog edits ]
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>
CPU frequency should never be negative.

If some client driver calls freq_qos_update_request with a
negative value which will be very high in absolute terms,
then frequency QoS sets max CPU freq at fmax as it considers
it's absolute value but it will add plist node with negative
priority.

plist node has priority from INT_MIN (highest) to INT_MAX(lowest).
Once priority is set as negative, another client will not be able
to reduce CPU frequency.

Adding check to make sure CPU freq is non-negative will fix
this problem.

Signed-off-by: Shivnandan Kumar &lt;quic_kshivnan@quicinc.com&gt;
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM: hibernate: defer device probing when resuming from hibernation</title>
<updated>2022-07-26T18:39:01+00:00</updated>
<author>
<name>Tetsuo Handa</name>
<email>penguin-kernel@I-love.SAKURA.ne.jp</email>
</author>
<published>2022-07-15T05:49:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8386c414e27caba8501119948e9551e52b527f59'/>
<id>8386c414e27caba8501119948e9551e52b527f59</id>
<content type='text'>
syzbot is reporting hung task at misc_open() [1], for there is a race
window of AB-BA deadlock which involves probe_count variable. Currently
wait_for_device_probe() from snapshot_open() from misc_open() can sleep
forever with misc_mtx held if probe_count cannot become 0.

When a device is probed by hub_event() work function, probe_count is
incremented before the probe function starts, and probe_count is
decremented after the probe function completed.

There are three cases that can prevent probe_count from dropping to 0.

  (a) A device being probed stopped responding (i.e. broken/malicious
      hardware).

  (b) A process emulating a USB device using /dev/raw-gadget interface
      stopped responding for some reason.

  (c) New device probe requests keeps coming in before existing device
      probe requests complete.

The phenomenon syzbot is reporting is (b). A process which is holding
system_transition_mutex and misc_mtx is waiting for probe_count to become
0 inside wait_for_device_probe(), but the probe function which is called
 from hub_event() work function is waiting for the processes which are
blocked at mutex_lock(&amp;misc_mtx) to respond via /dev/raw-gadget interface.

This patch mitigates (b) by deferring wait_for_device_probe() from
snapshot_open() to snapshot_write() and snapshot_ioctl(). Please note that
the possibility of (b) remains as long as any thread which is emulating a
USB device via /dev/raw-gadget interface can be blocked by uninterruptible
blocking operations (e.g. mutex_lock()).

Please also note that (a) and (c) are not addressed. Regarding (c), we
should change the code to wait for only one device which contains the
image for resuming from hibernation. I don't know how to address (a), for
use of timeout for wait_for_device_probe() might result in loss of user
data in the image. Maybe we should require the userland to wait for the
image device before opening /dev/snapshot interface.

Link: https://syzkaller.appspot.com/bug?extid=358c9ab4c93da7b7238c [1]
Reported-by: syzbot &lt;syzbot+358c9ab4c93da7b7238c@syzkaller.appspotmail.com&gt;
Signed-off-by: Tetsuo Handa &lt;penguin-kernel@I-love.SAKURA.ne.jp&gt;
Tested-by: syzbot &lt;syzbot+358c9ab4c93da7b7238c@syzkaller.appspotmail.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>
syzbot is reporting hung task at misc_open() [1], for there is a race
window of AB-BA deadlock which involves probe_count variable. Currently
wait_for_device_probe() from snapshot_open() from misc_open() can sleep
forever with misc_mtx held if probe_count cannot become 0.

When a device is probed by hub_event() work function, probe_count is
incremented before the probe function starts, and probe_count is
decremented after the probe function completed.

There are three cases that can prevent probe_count from dropping to 0.

  (a) A device being probed stopped responding (i.e. broken/malicious
      hardware).

  (b) A process emulating a USB device using /dev/raw-gadget interface
      stopped responding for some reason.

  (c) New device probe requests keeps coming in before existing device
      probe requests complete.

The phenomenon syzbot is reporting is (b). A process which is holding
system_transition_mutex and misc_mtx is waiting for probe_count to become
0 inside wait_for_device_probe(), but the probe function which is called
 from hub_event() work function is waiting for the processes which are
blocked at mutex_lock(&amp;misc_mtx) to respond via /dev/raw-gadget interface.

This patch mitigates (b) by deferring wait_for_device_probe() from
snapshot_open() to snapshot_write() and snapshot_ioctl(). Please note that
the possibility of (b) remains as long as any thread which is emulating a
USB device via /dev/raw-gadget interface can be blocked by uninterruptible
blocking operations (e.g. mutex_lock()).

Please also note that (a) and (c) are not addressed. Regarding (c), we
should change the code to wait for only one device which contains the
image for resuming from hibernation. I don't know how to address (a), for
use of timeout for wait_for_device_probe() might result in loss of user
data in the image. Maybe we should require the userland to wait for the
image device before opening /dev/snapshot interface.

Link: https://syzkaller.appspot.com/bug?extid=358c9ab4c93da7b7238c [1]
Reported-by: syzbot &lt;syzbot+358c9ab4c93da7b7238c@syzkaller.appspotmail.com&gt;
Signed-off-by: Tetsuo Handa &lt;penguin-kernel@I-love.SAKURA.ne.jp&gt;
Tested-by: syzbot &lt;syzbot+358c9ab4c93da7b7238c@syzkaller.appspotmail.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM: EM: convert power field to micro-Watts precision and align drivers</title>
<updated>2022-07-15T17:17:30+00:00</updated>
<author>
<name>Lukasz Luba</name>
<email>lukasz.luba@arm.com</email>
</author>
<published>2022-07-07T07:15:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ae6ccaa650380d243cf43d31c864c5ced2fd4612'/>
<id>ae6ccaa650380d243cf43d31c864c5ced2fd4612</id>
<content type='text'>
The milli-Watts precision causes rounding errors while calculating
efficiency cost for each OPP. This is especially visible in the 'simple'
Energy Model (EM), where the power for each OPP is provided from OPP
framework. This can cause some OPPs to be marked inefficient, while
using micro-Watts precision that might not happen.

Update all EM users which access 'power' field and assume the value is
in milli-Watts.

Solve also an issue with potential overflow in calculation of energy
estimation on 32bit machine. It's needed now since the power value
(thus the 'cost' as well) are higher.

Example calculation which shows the rounding error and impact:

power = 'dyn-power-coeff' * volt_mV * volt_mV * freq_MHz

power_a_uW = (100 * 600mW * 600mW * 500MHz) / 10^6 = 18000
power_a_mW = (100 * 600mW * 600mW * 500MHz) / 10^9 = 18

power_b_uW = (100 * 605mW * 605mW * 600MHz) / 10^6 = 21961
power_b_mW = (100 * 605mW * 605mW * 600MHz) / 10^9 = 21

max_freq = 2000MHz

cost_a_mW = 18 * 2000MHz/500MHz = 72
cost_a_uW = 18000 * 2000MHz/500MHz = 72000

cost_b_mW = 21 * 2000MHz/600MHz = 70 // &lt;- artificially better
cost_b_uW = 21961 * 2000MHz/600MHz = 73203

The 'cost_b_mW' (which is based on old milli-Watts) is misleadingly
better that the 'cost_b_uW' (this patch uses micro-Watts) and such
would have impact on the 'inefficient OPPs' information in the Cpufreq
framework. This patch set removes the rounding issue.

Signed-off-by: Lukasz Luba &lt;lukasz.luba@arm.com&gt;
Acked-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
Acked-by: Viresh Kumar &lt;viresh.kumar@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>
The milli-Watts precision causes rounding errors while calculating
efficiency cost for each OPP. This is especially visible in the 'simple'
Energy Model (EM), where the power for each OPP is provided from OPP
framework. This can cause some OPPs to be marked inefficient, while
using micro-Watts precision that might not happen.

Update all EM users which access 'power' field and assume the value is
in milli-Watts.

Solve also an issue with potential overflow in calculation of energy
estimation on 32bit machine. It's needed now since the power value
(thus the 'cost' as well) are higher.

Example calculation which shows the rounding error and impact:

power = 'dyn-power-coeff' * volt_mV * volt_mV * freq_MHz

power_a_uW = (100 * 600mW * 600mW * 500MHz) / 10^6 = 18000
power_a_mW = (100 * 600mW * 600mW * 500MHz) / 10^9 = 18

power_b_uW = (100 * 605mW * 605mW * 600MHz) / 10^6 = 21961
power_b_mW = (100 * 605mW * 605mW * 600MHz) / 10^9 = 21

max_freq = 2000MHz

cost_a_mW = 18 * 2000MHz/500MHz = 72
cost_a_uW = 18000 * 2000MHz/500MHz = 72000

cost_b_mW = 21 * 2000MHz/600MHz = 70 // &lt;- artificially better
cost_b_uW = 21961 * 2000MHz/600MHz = 73203

The 'cost_b_mW' (which is based on old milli-Watts) is misleadingly
better that the 'cost_b_uW' (this patch uses micro-Watts) and such
would have impact on the 'inefficient OPPs' information in the Cpufreq
framework. This patch set removes the rounding issue.

Signed-off-by: Lukasz Luba &lt;lukasz.luba@arm.com&gt;
Acked-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
Acked-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM: Use the enum req_op and blk_opf_t types</title>
<updated>2022-07-14T18:14:33+00:00</updated>
<author>
<name>Bart Van Assche</name>
<email>bvanassche@acm.org</email>
</author>
<published>2022-07-14T18:07:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=568e34ed7339e357f73c8e1ae5cc4f4595805357'/>
<id>568e34ed7339e357f73c8e1ae5cc4f4595805357</id>
<content type='text'>
Improve static type checking by using the enum req_op type for variables
that represent a request operation and the new blk_opf_t type for
variables that represent request flags. Combine the first two
hib_submit_io() arguments into a single argument.

Acked-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Cc: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Bart Van Assche &lt;bvanassche@acm.org&gt;
Link: https://lore.kernel.org/r/20220714180729.1065367-62-bvanassche@acm.org
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Improve static type checking by using the enum req_op type for variables
that represent a request operation and the new blk_opf_t type for
variables that represent request flags. Combine the first two
hib_submit_io() arguments into a single argument.

Acked-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Cc: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Bart Van Assche &lt;bvanassche@acm.org&gt;
Link: https://lore.kernel.org/r/20220714180729.1065367-62-bvanassche@acm.org
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>pm/sleep: Add PM_USERSPACE_AUTOSLEEP Kconfig</title>
<updated>2022-07-01T08:39:20+00:00</updated>
<author>
<name>Kalesh Singh</name>
<email>kaleshsingh@google.com</email>
</author>
<published>2022-06-30T19:12:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=261e224d6a5c43e2bb8a07b7662f9b4ec425cfec'/>
<id>261e224d6a5c43e2bb8a07b7662f9b4ec425cfec</id>
<content type='text'>
Systems that initiate frequent suspend/resume from userspace
can make the kernel aware by enabling PM_USERSPACE_AUTOSLEEP
config.

This allows for certain sleep-sensitive code (wireguard/rng) to
decide on what preparatory work should be performed (or not) in
their pm_notification callbacks.

This patch was prompted by the discussion at [1] which attempts
to remove CONFIG_ANDROID that currently guards these code paths.

[1] https://lore.kernel.org/r/20220629150102.1582425-1-hch@lst.de/

Suggested-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Acked-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Signed-off-by: Kalesh Singh &lt;kaleshsingh@google.com&gt;
Link: https://lore.kernel.org/r/20220630191230.235306-1-kaleshsingh@google.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Systems that initiate frequent suspend/resume from userspace
can make the kernel aware by enabling PM_USERSPACE_AUTOSLEEP
config.

This allows for certain sleep-sensitive code (wireguard/rng) to
decide on what preparatory work should be performed (or not) in
their pm_notification callbacks.

This patch was prompted by the discussion at [1] which attempts
to remove CONFIG_ANDROID that currently guards these code paths.

[1] https://lore.kernel.org/r/20220629150102.1582425-1-hch@lst.de/

Suggested-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Acked-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Signed-off-by: Kalesh Singh &lt;kaleshsingh@google.com&gt;
Link: https://lore.kernel.org/r/20220630191230.235306-1-kaleshsingh@google.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM: hibernate: Use kernel_can_power_off()</title>
<updated>2022-06-21T18:57:30+00:00</updated>
<author>
<name>Dmitry Osipenko</name>
<email>dmitry.osipenko@collabora.com</email>
</author>
<published>2022-06-17T12:24:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=202773260023b56e868d09d13d3a417028f1ff5b'/>
<id>202773260023b56e868d09d13d3a417028f1ff5b</id>
<content type='text'>
Use new kernel_can_power_off() API instead of legacy pm_power_off global
variable to fix regressed hibernation to disk where machine no longer
powers off when it should because ACPI power driver transitioned to the
new sys-off based API and it doesn't use pm_power_off anymore.

Fixes: 98f30d0ecf79 ("ACPI: power: Switch to sys-off handler API")
Tested-by: Ken Moffat &lt;zarniwhoop@ntlworld.com&gt;
Reported-by: Ken Moffat &lt;zarniwhhop@ntlworld.com&gt;
Signed-off-by: Dmitry Osipenko &lt;dmitry.osipenko@collabora.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>
Use new kernel_can_power_off() API instead of legacy pm_power_off global
variable to fix regressed hibernation to disk where machine no longer
powers off when it should because ACPI power driver transitioned to the
new sys-off based API and it doesn't use pm_power_off anymore.

Fixes: 98f30d0ecf79 ("ACPI: power: Switch to sys-off handler API")
Tested-by: Ken Moffat &lt;zarniwhoop@ntlworld.com&gt;
Reported-by: Ken Moffat &lt;zarniwhhop@ntlworld.com&gt;
Signed-off-by: Dmitry Osipenko &lt;dmitry.osipenko@collabora.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
