linux-toradex.git/drivers/scsi/scsi_pm.c, branch v5.16 Linux kernel for Apalis and Colibri modules scsi: core: pm: Only runtime resume if necessary 2021-10-17T01:08:39+00:00 Bart Van Assche bvanassche@acm.org 2021-10-06T21:54:53+00:00 9131bff6a9f1d4c6ab2d4673974a9659d8d24dc7 The following query shows which drivers define callbacks that are called by the power management support code in the SCSI core (scsi_pm.c): $ git grep -nHEwA16 "$(echo $(git grep -h 'scsi_register_driver(&' | sed 's/.*&//;s/\..*//') | sed 's/ /|/g')" | grep '\.pm[[:blank:]]*=[[:blank:]]' drivers/scsi/sd.c-620- .pm = &sd_pm_ops, drivers/scsi/sr.c-100- .pm = &sr_pm_ops, drivers/scsi/ufs/ufshcd.c-9765- .pm = &ufshcd_wl_pm_ops, Since unconditionally runtime resuming a device during system resume is not necessary, remove that code. Modify the SCSI disk (sd) driver such that it follows the same approach as the UFS driver, namely to skip system suspend and resume for devices that are runtime suspended. The CD-ROM code does not need to be updated since its PM callbacks do not affect the device power state. This patch has been tested as follows: [ shell 1 ] cd /sys/kernel/debug/tracing grep -E 'blk_(pre|post)_runtime|runtime_(suspend|resume)|autosuspend_delay|pm_runtime_(get|put)' available_filter_functions | while read a b; do echo "$a"; done | grep -v __pm_runtime_resume >set_ftrace_filter echo function > current_tracer echo 1 > tracing_on cat trace_pipe [ shell 2 ] cd /sys/block/sr0 # Increase the event poll interval to make it easier to derive from the # tracing output whether runtime power actions are the result of sg_inq. echo 30000 > events_poll_msecs cd device/power # Enable runtime power management. echo auto > control echo 1000 > autosuspend_delay_ms sleep 1 # Verify in shell 1 that sr0 has been runtime suspended sg_inq /dev/sr0 eject /dev/sr0 sg_inq /dev/sr0 # Disable runtime power management. echo on > control cd /sys/block/sda/device/power echo auto > control echo 1000 > autosuspend_delay_ms sleep 1 # Verify in shell 1 that sr0 has been runtime suspended sg_inq /dev/sda Link: https://lore.kernel.org/r/20211006215453.3318929-4-bvanassche@acm.org Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Martin Kepplinger <martin.kepplinger@puri.sm> Tested-by: Martin Kepplinger <martin.kepplinger@puri.sm> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> 
The following query shows which drivers define callbacks that are called by
the power management support code in the SCSI core (scsi_pm.c):

$ git grep -nHEwA16 "$(echo $(git grep -h 'scsi_register_driver(&' |
      sed 's/.*&//;s/\..*//') | sed 's/ /|/g')" |
    grep '\.pm[[:blank:]]*=[[:blank:]]'
drivers/scsi/sd.c-620-			.pm = &sd_pm_ops,
drivers/scsi/sr.c-100-			.pm = &sr_pm_ops,
drivers/scsi/ufs/ufshcd.c-9765-		.pm = &ufshcd_wl_pm_ops,

Since unconditionally runtime resuming a device during system resume is not
necessary, remove that code. Modify the SCSI disk (sd) driver such that it
follows the same approach as the UFS driver, namely to skip system suspend
and resume for devices that are runtime suspended. The CD-ROM code does not
need to be updated since its PM callbacks do not affect the device power
state.

This patch has been tested as follows:

[ shell 1 ]

cd /sys/kernel/debug/tracing
grep -E 'blk_(pre|post)_runtime|runtime_(suspend|resume)|autosuspend_delay|pm_runtime_(get|put)' available_filter_functions |
  while read a b; do echo "$a"; done |
  grep -v __pm_runtime_resume >set_ftrace_filter
echo function > current_tracer
echo 1 > tracing_on
cat trace_pipe

[ shell 2 ]

cd /sys/block/sr0
 # Increase the event poll interval to make it easier to derive from the
 # tracing output whether runtime power actions are the result of sg_inq.
echo 30000 > events_poll_msecs
cd device/power
 # Enable runtime power management.
echo auto > control
echo 1000 > autosuspend_delay_ms
sleep 1
 # Verify in shell 1 that sr0 has been runtime suspended
sg_inq /dev/sr0
eject /dev/sr0
sg_inq /dev/sr0
 # Disable runtime power management.
echo on > control

cd /sys/block/sda/device/power
echo auto > control
echo 1000 > autosuspend_delay_ms
sleep 1
 # Verify in shell 1 that sr0 has been runtime suspended
sg_inq /dev/sda

Link: https://lore.kernel.org/r/20211006215453.3318929-4-bvanassche@acm.org
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Martin Kepplinger <martin.kepplinger@puri.sm>
Tested-by: Martin Kepplinger <martin.kepplinger@puri.sm>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
scsi: core: pm: Rely on the device driver core for async power management 2021-10-17T01:08:39+00:00 Bart Van Assche bvanassche@acm.org 2021-10-06T21:54:51+00:00 a19a93e4c6a98c9c0f2f5a6db76846f10d7d1f85 Instead of implementing asynchronous resume support in the SCSI core, rely on the device driver core for resuming SCSI devices asynchronously. Instead of only supporting asynchronous resumes, also support asynchronous suspends. Link: https://lore.kernel.org/r/20211006215453.3318929-2-bvanassche@acm.org Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Martin Kepplinger <martin.kepplinger@puri.sm> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> 
Instead of implementing asynchronous resume support in the SCSI core, rely
on the device driver core for resuming SCSI devices asynchronously.
Instead of only supporting asynchronous resumes, also support asynchronous
suspends.

Link: https://lore.kernel.org/r/20211006215453.3318929-2-bvanassche@acm.org
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Martin Kepplinger <martin.kepplinger@puri.sm>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
scsi: block: pm: Simplify resume handling 2020-07-25T02:09:55+00:00 Alan Stern stern@rowland.harvard.edu 2020-07-06T15:14:36+00:00 8f38f8e0a30e1c33cdfc48eba2bd63ac2eae373a Commit 05d18ae1cc8a ("scsi: pm: Balance pm_only counter of request queue during system resume") fixed a problem in the block layer's runtime-PM code: blk_set_runtime_active() failed to call blk_clear_pm_only(). However, the commit's implementation was awkward; it forced the SCSI system-resume handler to choose whether to call blk_post_runtime_resume() or blk_set_runtime_active(), depending on whether or not the SCSI device had previously been runtime suspended. This patch simplifies the situation considerably by adding the missing function call directly into blk_set_runtime_active() (under the condition that the queue is not already in the RPM_ACTIVE state). This allows the SCSI routine to revert back to its original form. Furthermore, making this change reveals that blk_post_runtime_resume() (in its success pathway) does exactly the same thing as blk_set_runtime_active(). The duplicate code is easily removed by making one routine call the other. No functional changes are intended. Link: https://lore.kernel.org/r/20200706151436.GA702867@rowland.harvard.edu CC: Can Guo <cang@codeaurora.org> CC: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> 
Commit 05d18ae1cc8a ("scsi: pm: Balance pm_only counter of request queue
during system resume") fixed a problem in the block layer's runtime-PM
code: blk_set_runtime_active() failed to call blk_clear_pm_only().
However, the commit's implementation was awkward; it forced the SCSI
system-resume handler to choose whether to call blk_post_runtime_resume()
or blk_set_runtime_active(), depending on whether or not the SCSI device
had previously been runtime suspended.

This patch simplifies the situation considerably by adding the missing
function call directly into blk_set_runtime_active() (under the condition
that the queue is not already in the RPM_ACTIVE state).  This allows the
SCSI routine to revert back to its original form.  Furthermore, making this
change reveals that blk_post_runtime_resume() (in its success pathway) does
exactly the same thing as blk_set_runtime_active().  The duplicate code is
easily removed by making one routine call the other.

No functional changes are intended.

Link: https://lore.kernel.org/r/20200706151436.GA702867@rowland.harvard.edu
CC: Can Guo <cang@codeaurora.org>
CC: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
scsi: pm: Balance pm_only counter of request queue during system resume 2020-05-11T23:43:25+00:00 Can Guo cang@codeaurora.org 2020-05-06T04:55:35+00:00 05d18ae1cc8a0308b12f37b4ab94afce3535fac9 During system resume, scsi_resume_device() decreases a request queue's pm_only counter if the scsi device was quiesced before. But after that, if the scsi device's RPM status is RPM_SUSPENDED, the pm_only counter is still held (non-zero). Current SCSI resume hook only sets the RPM status of the scsi_device and its request queue to RPM_ACTIVE, but leaves the pm_only counter unchanged. This may make the request queue's pm_only counter remain non-zero after resume hook returns, hence those who are waiting on the mq_freeze_wq would never be woken up. Fix this by calling blk_post_runtime_resume() if a sdev's RPM status was RPM_SUSPENDED. (struct request_queue)0xFFFFFF815B69E938 pm_only = (counter = 2), rpm_status = 0, dev = 0xFFFFFF815B0511A0, ((struct device)0xFFFFFF815B0511A0)).power is_suspended = FALSE, runtime_status = RPM_ACTIVE, (struct scsi_device)0xffffff815b051000 request_queue = 0xFFFFFF815B69E938, sdev_state = SDEV_RUNNING, quiesced_by = 0x0, B::v.f_/task_0xFFFFFF810C246940 -000|__switch_to(prev = 0xFFFFFF810C246940, next = 0xFFFFFF80A49357C0) -001|context_switch(inline) -001|__schedule(?) -002|schedule() -003|blk_queue_enter(q = 0xFFFFFF815B69E938, flags = 0) -004|generic_make_request(?) -005|submit_bio(bio = 0xFFFFFF80A8195B80) Link: https://lore.kernel.org/r/1588740936-28846-1-git-send-email-cang@codeaurora.org Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Can Guo <cang@codeaurora.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> 
During system resume, scsi_resume_device() decreases a request queue's
pm_only counter if the scsi device was quiesced before. But after that, if
the scsi device's RPM status is RPM_SUSPENDED, the pm_only counter is still
held (non-zero). Current SCSI resume hook only sets the RPM status of the
scsi_device and its request queue to RPM_ACTIVE, but leaves the pm_only
counter unchanged. This may make the request queue's pm_only counter remain
non-zero after resume hook returns, hence those who are waiting on the
mq_freeze_wq would never be woken up. Fix this by calling
blk_post_runtime_resume() if a sdev's RPM status was RPM_SUSPENDED.

(struct request_queue)0xFFFFFF815B69E938
	pm_only = (counter = 2),
	rpm_status = 0,
	dev = 0xFFFFFF815B0511A0,

((struct device)0xFFFFFF815B0511A0)).power
	is_suspended = FALSE,
	runtime_status = RPM_ACTIVE,

(struct scsi_device)0xffffff815b051000
	request_queue = 0xFFFFFF815B69E938,
	sdev_state = SDEV_RUNNING,
	quiesced_by = 0x0,

B::v.f_/task_0xFFFFFF810C246940
-000|__switch_to(prev = 0xFFFFFF810C246940, next = 0xFFFFFF80A49357C0)
-001|context_switch(inline)
-001|__schedule(?)
-002|schedule()
-003|blk_queue_enter(q = 0xFFFFFF815B69E938, flags = 0)
-004|generic_make_request(?)
-005|submit_bio(bio = 0xFFFFFF80A8195B80)

Link: https://lore.kernel.org/r/1588740936-28846-1-git-send-email-cang@codeaurora.org
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
scsi: core: remove dummy q->dev check 2019-09-12T13:11:58+00:00 Stanley Chu stanley.chu@mediatek.com 2019-09-12T08:35:28+00:00 b804049dce9128a88558bc1594ff96d6632fbc10 Currently blk_set_runtime_active() is checking if q->dev is null by itself, thus remove the same checking in its user: scsi_dev_type_resume(). Signed-off-by: Stanley Chu <stanley.chu@mediatek.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> 
Currently blk_set_runtime_active() is checking if q->dev is null by
itself, thus remove the same checking in its user: scsi_dev_type_resume().

Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi 2019-07-11T22:14:01+00:00 Linus Torvalds torvalds@linux-foundation.org 2019-07-11T22:14:01+00:00 ba6d10ab8014ac10d25ca513352b6665e73b5785 Pull SCSI updates from James Bottomley: "This is mostly update of the usual drivers: qla2xxx, hpsa, lpfc, ufs, mpt3sas, ibmvscsi, megaraid_sas, bnx2fc and hisi_sas as well as the removal of the osst driver (I heard from Willem privately that he would like the driver removed because all his test hardware has failed). Plus number of minor changes, spelling fixes and other trivia. The big merge conflict this time around is the SPDX licence tags. Following discussion on linux-next, we believe our version to be more accurate than the one in the tree, so the resolution is to take our version for all the SPDX conflicts" Note on the SPDX license tag conversion conflicts: the SCSI tree had done its own SPDX conversion, which in some cases conflicted with the treewide ones done by Thomas & co. In almost all cases, the conflicts were purely syntactic: the SCSI tree used the old-style SPDX tags ("GPL-2.0" and "GPL-2.0+") while the treewide conversion had used the new-style ones ("GPL-2.0-only" and "GPL-2.0-or-later"). In these cases I picked the new-style one. In a few cases, the SPDX conversion was actually different, though. As explained by James above, and in more detail in a pre-pull-request thread: "The other problem is actually substantive: In the libsas code Luben Tuikov originally specified gpl 2.0 only by dint of stating: * This file is licensed under GPLv2. In all the libsas files, but then muddied the water by quoting GPLv2 verbatim (which includes the or later than language). So for these files Christoph did the conversion to v2 only SPDX tags and Thomas converted to v2 or later tags" So in those cases, where the spdx tag substantially mattered, I took the SCSI tree conversion of it, but then also took the opportunity to turn the old-style "GPL-2.0" into a new-style "GPL-2.0-only" tag. Similarly, when there were whitespace differences or other differences to the comments around the copyright notices, I took the version from the SCSI tree as being the more specific conversion. Finally, in the spdx conversions that had no conflicts (because the treewide ones hadn't been done for those files), I just took the SCSI tree version as-is, even if it was old-style. The old-style conversions are perfectly valid, even if the "-only" and "-or-later" versions are perhaps more descriptive. * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (185 commits) scsi: qla2xxx: move IO flush to the front of NVME rport unregistration scsi: qla2xxx: Fix NVME cmd and LS cmd timeout race condition scsi: qla2xxx: on session delete, return nvme cmd scsi: qla2xxx: Fix kernel crash after disconnecting NVMe devices scsi: megaraid_sas: Update driver version to 07.710.06.00-rc1 scsi: megaraid_sas: Introduce various Aero performance modes scsi: megaraid_sas: Use high IOPS queues based on IO workload scsi: megaraid_sas: Set affinity for high IOPS reply queues scsi: megaraid_sas: Enable coalescing for high IOPS queues scsi: megaraid_sas: Add support for High IOPS queues scsi: megaraid_sas: Add support for MPI toolbox commands scsi: megaraid_sas: Offload Aero RAID5/6 division calculations to driver scsi: megaraid_sas: RAID1 PCI bandwidth limit algorithm is applicable for only Ventura scsi: megaraid_sas: megaraid_sas: Add check for count returned by HOST_DEVICE_LIST DCMD scsi: megaraid_sas: Handle sequence JBOD map failure at driver level scsi: megaraid_sas: Don't send FPIO to RL Bypass queue scsi: megaraid_sas: In probe context, retry IOC INIT once if firmware is in fault scsi: megaraid_sas: Release Mutex lock before OCR in case of DCMD timeout scsi: megaraid_sas: Call disable_irq from process IRQ poll scsi: megaraid_sas: Remove few debug counters from IO path ... 
Pull SCSI updates from James Bottomley:
 "This is mostly update of the usual drivers: qla2xxx, hpsa, lpfc, ufs,
  mpt3sas, ibmvscsi, megaraid_sas, bnx2fc and hisi_sas as well as the
  removal of the osst driver (I heard from Willem privately that he
  would like the driver removed because all his test hardware has
  failed). Plus number of minor changes, spelling fixes and other
  trivia.

  The big merge conflict this time around is the SPDX licence tags.
  Following discussion on linux-next, we believe our version to be more
  accurate than the one in the tree, so the resolution is to take our
  version for all the SPDX conflicts"

Note on the SPDX license tag conversion conflicts: the SCSI tree had
done its own SPDX conversion, which in some cases conflicted with the
treewide ones done by Thomas & co.

In almost all cases, the conflicts were purely syntactic: the SCSI tree
used the old-style SPDX tags ("GPL-2.0" and "GPL-2.0+") while the
treewide conversion had used the new-style ones ("GPL-2.0-only" and
"GPL-2.0-or-later").

In these cases I picked the new-style one.

In a few cases, the SPDX conversion was actually different, though.  As
explained by James above, and in more detail in a pre-pull-request
thread:

 "The other problem is actually substantive: In the libsas code Luben
  Tuikov originally specified gpl 2.0 only by dint of stating:

  * This file is licensed under GPLv2.

  In all the libsas files, but then muddied the water by quoting GPLv2
  verbatim (which includes the or later than language). So for these
  files Christoph did the conversion to v2 only SPDX tags and Thomas
  converted to v2 or later tags"

So in those cases, where the spdx tag substantially mattered, I took the
SCSI tree conversion of it, but then also took the opportunity to turn
the old-style "GPL-2.0" into a new-style "GPL-2.0-only" tag.

Similarly, when there were whitespace differences or other differences
to the comments around the copyright notices, I took the version from
the SCSI tree as being the more specific conversion.

Finally, in the spdx conversions that had no conflicts (because the
treewide ones hadn't been done for those files), I just took the SCSI
tree version as-is, even if it was old-style.  The old-style conversions
are perfectly valid, even if the "-only" and "-or-later" versions are
perhaps more descriptive.

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (185 commits)
  scsi: qla2xxx: move IO flush to the front of NVME rport unregistration
  scsi: qla2xxx: Fix NVME cmd and LS cmd timeout race condition
  scsi: qla2xxx: on session delete, return nvme cmd
  scsi: qla2xxx: Fix kernel crash after disconnecting NVMe devices
  scsi: megaraid_sas: Update driver version to 07.710.06.00-rc1
  scsi: megaraid_sas: Introduce various Aero performance modes
  scsi: megaraid_sas: Use high IOPS queues based on IO workload
  scsi: megaraid_sas: Set affinity for high IOPS reply queues
  scsi: megaraid_sas: Enable coalescing for high IOPS queues
  scsi: megaraid_sas: Add support for High IOPS queues
  scsi: megaraid_sas: Add support for MPI toolbox commands
  scsi: megaraid_sas: Offload Aero RAID5/6 division calculations to driver
  scsi: megaraid_sas: RAID1 PCI bandwidth limit algorithm is applicable for only Ventura
  scsi: megaraid_sas: megaraid_sas: Add check for count returned by HOST_DEVICE_LIST DCMD
  scsi: megaraid_sas: Handle sequence JBOD map failure at driver level
  scsi: megaraid_sas: Don't send FPIO to RL Bypass queue
  scsi: megaraid_sas: In probe context, retry IOC INIT once if firmware is in fault
  scsi: megaraid_sas: Release Mutex lock before OCR in case of DCMD timeout
  scsi: megaraid_sas: Call disable_irq from process IRQ poll
  scsi: megaraid_sas: Remove few debug counters from IO path
  ...
scsi: sd: Rely on the driver core for asynchronous probing 2019-06-18T23:46:17+00:00 Bart Van Assche bvanassche@acm.org 2019-04-30T21:39:18+00:00 f049cf1a7b6737c75884247c3f6383ef104d255a As explained during the 2018 LSF/MM session about increasing SCSI disk probing concurrency, the problems with the current probing approach are as follows: - The driver core is unaware of asynchronous SCSI LUN probing. wait_for_device_probe() waits for all asynchronous probes except asynchronous SCSI disk probes. - There is unnecessary serialization between sd_probe() and sd_remove(). This can lead to a deadlock. Hence this patch that modifies the sd driver such that it uses the driver core framework for asynchronous probing. The async domain and get_device()/put_device() pairs that became superfluous due to this change are removed. This patch does not affect the time needed for loading the scsi_debug kernel module with parameters delay=0 and max_luns=256. This patch depends on commit ef0ff68351be ("driver core: Probe devices asynchronously instead of the driver") that went upstream in kernel version v5.1-rc1. Cc: Lee Duncan <lduncan@suse.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Johannes Thumshirn <jthumshirn@suse.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Pavel Machek <pavel@ucw.cz> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> 
As explained during the 2018 LSF/MM session about increasing SCSI disk
probing concurrency, the problems with the current probing approach are as
follows:

 - The driver core is unaware of asynchronous SCSI LUN probing.
   wait_for_device_probe() waits for all asynchronous probes except
   asynchronous SCSI disk probes.

 - There is unnecessary serialization between sd_probe() and sd_remove().
   This can lead to a deadlock.

Hence this patch that modifies the sd driver such that it uses the driver
core framework for asynchronous probing. The async domain and
get_device()/put_device() pairs that became superfluous due to this change
are removed.

This patch does not affect the time needed for loading the scsi_debug
kernel module with parameters delay=0 and max_luns=256.

This patch depends on commit ef0ff68351be ("driver core: Probe devices
asynchronously instead of the driver") that went upstream in kernel version
v5.1-rc1.

Cc: Lee Duncan <lduncan@suse.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
scsi: core: add SPDX tags to scsi midlayer files missing licensing information 2019-05-21T10:16:21+00:00 Christoph Hellwig hch@lst.de 2019-05-01T16:13:54+00:00 026104bfa591709689e12434c1bb3b485bf5bfa0 Add the default kernel GPLv2 annotation to SCSI midlayer files missing any licensing information. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> 
Add the default kernel GPLv2 annotation to SCSI midlayer files missing any
licensing information.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
treewide: Add SPDX license identifier for missed files 2019-05-21T08:50:45+00:00 Thomas Gleixner tglx@linutronix.de 2019-05-19T12:08:55+00:00 457c89965399115e5cd8bf38f9c597293405703d Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Add SPDX license identifiers to all files which:

 - Have no license information of any form

 - Have EXPORT_.*_SYMBOL_GPL inside which was used in the
   initial scan/conversion to ignore the file

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
scsi: core: Synchronize request queue PM status only on successful resume 2019-01-09T02:57:26+00:00 Stanley Chu stanley.chu@mediatek.com 2019-01-03T14:08:05+00:00 3f7e62bba0003f9c68f599f5997c4647ef5b4f4e The commit 356fd2663cff ("scsi: Set request queue runtime PM status back to active on resume") fixed up the inconsistent RPM status between request queue and device. However changing request queue RPM status shall be done only on successful resume, otherwise status may be still inconsistent as below, Request queue: RPM_ACTIVE Device: RPM_SUSPENDED This ends up soft lockup because requests can be submitted to underlying devices but those devices and their required resource are not resumed. For example, After above inconsistent status happens, IO request can be submitted to UFS device driver but required resource (like clock) is not resumed yet thus lead to warning as below call stack, WARN_ON(hba->clk_gating.state != CLKS_ON); ufshcd_queuecommand scsi_dispatch_cmd scsi_request_fn __blk_run_queue cfq_insert_request __elv_add_request blk_flush_plug_list blk_finish_plug jbd2_journal_commit_transaction kjournald2 We may see all behind IO requests hang because of no response from storage host or device and then soft lockup happens in system. In the end, system may crash in many ways. Fixes: 356fd2663cff (scsi: Set request queue runtime PM status back to active on resume) Cc: stable@vger.kernel.org Signed-off-by: Stanley Chu <stanley.chu@mediatek.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> 
The commit 356fd2663cff ("scsi: Set request queue runtime PM status back to
active on resume") fixed up the inconsistent RPM status between request
queue and device. However changing request queue RPM status shall be done
only on successful resume, otherwise status may be still inconsistent as
below,

Request queue: RPM_ACTIVE
Device: RPM_SUSPENDED

This ends up soft lockup because requests can be submitted to underlying
devices but those devices and their required resource are not resumed.

For example,

After above inconsistent status happens, IO request can be submitted to UFS
device driver but required resource (like clock) is not resumed yet thus
lead to warning as below call stack,

WARN_ON(hba->clk_gating.state != CLKS_ON);
ufshcd_queuecommand
scsi_dispatch_cmd
scsi_request_fn
__blk_run_queue
cfq_insert_request
__elv_add_request
blk_flush_plug_list
blk_finish_plug
jbd2_journal_commit_transaction
kjournald2

We may see all behind IO requests hang because of no response from storage
host or device and then soft lockup happens in system. In the end, system
may crash in many ways.

Fixes: 356fd2663cff (scsi: Set request queue runtime PM status back to active on resume)
Cc: stable@vger.kernel.org
Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>