The primary role of pm_runtime_put() is to decrement the runtime PM
usage counter of the given device. It always does that regardless of
the value returned by it later.
In addition, if the runtime PM usage counter after decrementation turns
out to be zero, a work item is queued up to check whether or not the
device can be suspended. This is not guaranteed to succeed though and
even if it is successful, the device may still not be suspended going
forward.
There are multiple valid reasons why pm_runtime_put() may not decide to
queue up the work item mentioned above, including, but not limited to,
the case when user space has written "on" to the device's runtime PM
"control" file in sysfs. In all of those cases, pm_runtime_put()
returns a negative error code (even though the device's runtime PM
usage counter has been successfully decremented by it) which is very
confusing. In fact, its return value should only be used for debug
purposes and care should be taken when doing it even in that case.
Accordingly, to avoid the confusion mentioned above, change the return
type of pm_runtime_put() to void.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Link: https://patch.msgid.link/14387202.RDIVbhacDa@rafael.j.wysocki
Add wrapper macros for ACQUIRE()/ACQUIRE_ERR() and runtime PM
usage counter guards introduced recently: pm_runtime_active_try,
pm_runtime_active_auto_try, pm_runtime_active_try_enabled, and
pm_runtime_active_auto_try_enabled.
The new macros should be more straightforward to use.
For example, they can be used for rewriting a piece of code like below:
ACQUIRE(pm_runtime_active_try, pm)(dev);
if ((ret = ACQUIRE_ERR(pm_runtime_active_try, &pm)))
return ret;
in the following way:
PM_RUNTIME_ACQUIRE(dev, pm);
if ((ret = PM_RUNTIME_ACQUIRE_ERR(&pm)))
return ret;
If the original code does not care about the specific error code
returned when attepmting to resume the device:
ACQUIRE(pm_runtime_active_try, pm)(dev);
if (ACQUIRE_ERR(pm_runtime_active_try, &pm))
return -ENXIO;
it may be changed like this:
PM_RUNTIME_ACQUIRE(dev, pm);
if (PM_RUNTIME_ACQUIRE_ERR(&pm))
return -ENXIO;
Link: https://lore.kernel.org/linux-pm/5068916.31r3eYUQgx@rafael.j.wysocki/
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/3400866.aeNJFYEL58@rafael.j.wysocki
Follow previous commit 9a0abc3945 ("PM: runtime: Add auto-cleanup
macros for "resume and get" operations") and define a runtime PM
usage counter guard in which pm_runtime_get_noresume() and
pm_runtime_put_noidle() will be used for incrementing and
decrementing it, respectively.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Jonathan Cameron <jonathan.cameorn@huawei.com>
The DEFINE_FREE() for pm_runtime_put has been superseded by recently
introduced runtime PM auto-cleanup macros and its only user has been
converted to using one of the new macros, so drop it.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
It is generally useful to be able to automatically drop a device's
runtime PM usage counter incremented by runtime PM operations that
resume a device and bump up its usage counter [1].
To that end, add guard definition macros allowing pm_runtime_put()
and pm_runtime_put_autosuspend() to be used for the auto-cleanup in
those cases.
Simply put, a piece of code like below:
pm_runtime_get_sync(dev);
.....
pm_runtime_put(dev);
return 0;
can be transformed with guard() like:
guard(pm_runtime_active)(dev);
.....
return 0;
(see the pm_runtime_put() call is gone).
However, it is better to do proper error handling in the majority of
cases, so doing something like this instead of the above is recommended:
ACQUIRE(pm_runtime_active_try, pm)(dev);
if (ACQUIRE_ERR(pm_runtime_active_try, &pm))
return -ENXIO;
.....
return 0;
In all of the cases in which runtime PM is known to be enabled for the
given device or the device can be regarded as operational (and so it can
be accessed) with runtime PM disabled, a piece of code like:
ret = pm_runtime_resume_and_get(dev);
if (ret < 0)
return ret;
.....
pm_runtime_put(dev);
return 0;
can be changed as follows:
ACQUIRE(pm_runtime_active_try, pm)(dev);
ret = ACQUIRE_ERR(pm_runtime_active_try, &pm);
if (ret < 0)
return ret;
.....
return 0;
(again, see the pm_runtime_put() call is gone).
Still, if the device cannot be accessed unless runtime PM has been
enabled for it, the pm_runtime_active_try_enabled guard variant
needs to be used, that is (in the context of the example above):
ACQUIRE(pm_runtime_active_try_enabled, pm)(dev);
ret = ACQUIRE_ERR(pm_runtime_active_try_enabled, &pm);
if (ret < 0)
return ret;
.....
return 0;
When the original code calls pm_runtime_put_autosuspend(), use one
of the "auto" guard variants, pm_runtime_active_auto/_try/_enabled,
so for example, a piece of code like:
ret = pm_runtime_resume_and_get(dev);
if (ret < 0)
return ret;
.....
pm_runtime_put_autosuspend(dev);
return 0;
will become:
ACQUIRE(pm_runtime_active_auto_try_enabled, pm)(dev);
ret = ACQUIRE_ERR(pm_runtime_active_auto_try_enabled, &pm);
if (ret < 0)
return ret;
.....
return 0;
Note that the cases in which the return value of pm_runtime_get_sync()
is checked can also be handled with the help of the new guard macros.
For example, a piece of code like:
ret = pm_runtime_get_sync(dev);
if (ret < 0) {
pm_runtime_put(dev);
return ret;
}
.....
pm_runtime_put(dev);
return 0;
can be rewritten as:
ACQUIRE(pm_runtime_active_auto_try_enabled, pm)(dev);
ret = ACQUIRE_ERR(pm_runtime_active_auto_try_enabled, &pm);
if (ret < 0)
return ret;
.....
return 0;
or pm_runtime_get_active_try can be used if transparent handling of
disabled runtime PM is desirable.
Link: https://lore.kernel.org/linux-pm/878qimv24u.wl-tiwai@suse.de/ [1]
Link: https://lore.kernel.org/linux-pm/20250926150613.000073a4@huawei.com/
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/2238241.irdbgypaU6@rafael.j.wysocki
[ rjw: Fixed leftovers from the previous version in the changelog ]
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
APIs based on __pm_runtime_idle() (pm_runtime_idle(), pm_request_idle())
do not return 1 when already suspended. They return -EAGAIN. This is
already covered in the docs, so the entry for "1" is redundant and
conflicting.
(pm_runtime_put() and pm_runtime_put_sync() were previously incorrect,
but that's fixed in "PM: runtime: pm_runtime_put{,_sync}() returns 1
when already suspended", to ensure consistency with APIs like
pm_runtime_put_autosuspend().)
RPM_GET_PUT APIs based on __pm_runtime_suspend() do return 1 when
already suspended, but the language is a little unclear -- it's not
really an "error", so it seems better to list as a clarification before
the 0/success case. Additionally, they only actually return 1 when the
refcount makes it to 0; if the usage counter is still non-zero, we
return 0.
pm_runtime_put(), etc., also don't appear at first like they can ever
see "-EAGAIN: Runtime PM usage_count non-zero", because in non-racy
conditions, pm_runtime_put() would drop its reference count, see it's
non-zero, and return early (in __pm_runtime_idle()). However, it's
possible to race with another actor that increments the usage_count
afterward, since rpm_idle() is protected by a separate lock; in such a
case, we may see -EAGAIN.
Because this case is only seen in the presence of concurrent actors, it
makes sense to clarify that this is when "usage_count **became**
non-zero", by way of some racing actor.
Lastly, pm_runtime_put_sync_suspend() duplicated some -EAGAIN language.
Fix that.
Fixes: 271ff96d60 ("PM: runtime: Document return values of suspend-related API functions")
Link: https://lore.kernel.org/linux-pm/aJ5pkEJuixTaybV4@google.com/
Signed-off-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: 6.17+ <stable@vger.kernel.org> # 6.17+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Merge runtime PM updates and power capping updates for 6.17-rc1:
- Document return values of suspend-related API functions in the
runtime PM framework (Sakari Ailus)
- Mark last busy stamp in multiple autosuspend-related functions in the
runtime PM framework and update its documentation (Sakari Ailus)
- Take active children into account in pm_runtime_get_if_in_use() for
consistency (Rafael Wysocki)
- Fix NULL pointer dereference in get_pd_power_uw() in the dtpm_cpu
power capping driver (Sivan Zohar-Kotzer)
- Add support for the Bartlett Lake platform to the Intel RAPL power
capping driver (Qiao Wei)
- Add PL4 support for Panther Lake to the intel_rapl_msr power capping
driver (Zhang Rui)
* pm-runtime:
PM: runtime: Take active children into account in pm_runtime_get_if_in_use()
Documentation: PM: *_autosuspend() functions update last busy time
PM: runtime: Mark last busy stamp in pm_request_autosuspend()
PM: runtime: Mark last busy stamp in pm_runtime_autosuspend()
PM: runtime: Mark last busy stamp in pm_runtime_put_sync_autosuspend()
PM: runtime: Mark last busy stamp in pm_runtime_put_autosuspend()
PM: runtime: Document return values of suspend-related API functions
* pm-powercap:
powercap: dtpm_cpu: Fix NULL pointer dereference in get_pd_power_uw()
powercap: intel_rapl: Add support for Bartlett Lake platform
powercap: intel_rapl_msr: Add PL4 support for Panther Lake
Since pm_runtime_force_resume() and pm_runtime_need_not_resume() are only
needed for handling system-wide PM transitions, there is no reason to
compile them in if CONFIG_PM_SLEEP is unset.
Accordingly, move them under CONFIG_PM_SLEEP and make the static
inline stub for pm_runtime_force_resume() return an error to indicate
that it should not be used outside CONFIG_PM_SLEEP.
Putting pm_runtime_force_resume() also allows subsequent changes to
be more straightforward because this function is going to access a
device PM flag that is only defined when CONFIG_PM_SLEEP is set.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://patch.msgid.link/3384523.aeNJFYEL58@rjwysocki.net
Pull pci updates from Bjorn Helgaas:
"Enumeration:
- Print the actual delay time in pci_bridge_wait_for_secondary_bus()
instead of assuming it was 1000ms (Wilfred Mallawa)
- Revert 'iommu/amd: Prevent binding other PCI drivers to IOMMU PCI
devices', which broke resume from system sleep on AMD platforms and
has been fixed by other commits (Lukas Wunner)
Resource management:
- Remove mtip32xx use of pcim_iounmap_regions(), which is deprecated
and unnecessary (Philipp Stanner)
- Remove pcim_iounmap_regions() and pcim_request_region_exclusive()
and related flags since all uses have been removed (Philipp
Stanner)
- Rework devres 'request' functions so they are no longer 'hybrid',
i.e., their behavior no longer depends on whether
pcim_enable_device or pci_enable_device() was used, and remove
related code (Philipp Stanner)
- Warn (not BUG()) about failure to assign optional resources (Ilpo
Järvinen)
Error handling:
- Log the DPC Error Source ID only when it's actually valid (when
ERR_FATAL or ERR_NONFATAL was received from a downstream device)
and decode into bus/device/function (Bjorn Helgaas)
- Determine AER log level once and save it so all related messages
use the same level (Karolina Stolarek)
- Use KERN_WARNING, not KERN_ERR, when logging PCIe Correctable
Errors (Karolina Stolarek)
- Ratelimit PCIe Correctable and Non-Fatal error logging, with sysfs
controls on interval and burst count, to avoid flooding logs and
RCU stall warnings (Jon Pan-Doh)
Power management:
- Increment PM usage counter when probing reset methods so we don't
try to read config space of a powered-off device (Alex Williamson)
- Set all devices to D0 during enumeration to ensure ACPI opregion is
connected via _REG (Mario Limonciello)
Power control:
- Rename pwrctrl Kconfig symbols from 'PWRCTL' to 'PWRCTRL' to match
the filename paths. Retain old deprecated symbols for
compatibility, except for the pwrctrl slot driver
(PCI_PWRCTRL_SLOT) (Johan Hovold)
- When unregistering pwrctrl, cancel outstanding rescan work before
cleaning up data structures to avoid use-after-free issues (Brian
Norris)
Bandwidth control:
- Simplify link bandwidth controller by replacing the count of Link
Bandwidth Management Status (LBMS) events with a PCI_LINK_LBMS_SEEN
flag (Ilpo Järvinen)
- Update the Link Speed after retraining, since the Link Speed may
have changed (Ilpo Järvinen)
PCIe native device hotplug:
- Ignore Presence Detect Changed caused by DPC.
pciehp already ignores Link Down/Up events caused by DPC, but on
slots using in-band presence detect, DPC causes a spurious Presence
Detect Changed event (Lukas Wunner)
- Ignore Link Down/Up caused by Secondary Bus Reset.
On hotplug ports using in-band presence detect, the reset causes a
Presence Detect Changed event, which mistakenly caused teardown and
re-enumeration of the device. Drivers may need to annotate code
that resets their device (Lukas Wunner)
Virtualization:
- Add an ACS quirk for Loongson Root Ports that don't advertise ACS
but don't allow peer-to-peer transactions between Root Ports; the
quirk allows each Root Port to be in a separate IOMMU group (Huacai
Chen)
Endpoint framework:
- For fixed-size BARs, retain both the actual size and the possibly
larger size allocated to accommodate iATU alignment requirements
(Jerome Brunet)
- Simplify ctrl/SPAD space allocation and avoid allocating more space
than needed (Jerome Brunet)
- Correct MSI-X PBA offset calculations for DesignWare and Cadence
endpoint controllers (Niklas Cassel)
- Align the return value (number of interrupts) encoding for
pci_epc_get_msi()/pci_epc_ops::get_msi() and
pci_epc_get_msix()/pci_epc_ops::get_msix() (Niklas Cassel)
- Align the nr_irqs parameter encoding for
pci_epc_set_msi()/pci_epc_ops::set_msi() and
pci_epc_set_msix()/pci_epc_ops::set_msix() (Niklas Cassel)
Common host controller library:
- Convert pci-host-common to a library so platforms that don't need
native host controller drivers don't need to include these helper
functions (Manivannan Sadhasivam)
Apple PCIe controller driver:
- Extract ECAM bridge creation helper from pci_host_common_probe() to
separate driver-specific things like MSI from PCI things (Marc
Zyngier)
- Dynamically allocate RID-to_SID bitmap to prepare for SoCs with
varying capabilities (Marc Zyngier)
- Skip ports disabled in DT when setting up ports (Janne Grunau)
- Add t6020 compatible string (Alyssa Rosenzweig)
- Add T602x PCIe support (Hector Martin)
- Directly set/clear INTx mask bits because T602x dropped the
accessors that could do this without locking (Marc Zyngier)
- Move port PHY registers to their own reg items to accommodate
T602x, which moves them around; retain default offsets for existing
DTs that lack phy%d entries with the reg offsets (Hector Martin)
- Stop polling for core refclk, which doesn't work on T602x and the
bootloader has already done anyway (Hector Martin)
- Use gpiod_set_value_cansleep() when asserting PERST# in probe
because we're allowed to sleep there (Hector Martin)
Cadence PCIe controller driver:
- Drop a runtime PM 'put' to resolve a runtime atomic count underflow
(Hans Zhang)
- Make the cadence core buildable as a module (Kishon Vijay Abraham I)
- Add cdns_pcie_host_disable() and cdns_pcie_ep_disable() for use by
loadable drivers when they are removed (Siddharth Vadapalli)
Freescale i.MX6 PCIe controller driver:
- Apply link training workaround only on IMX6Q, IMX6SX, IMX6SP
(Richard Zhu)
- Remove redundant dw_pcie_wait_for_link() from
imx_pcie_start_link(); since the DWC core does this, imx6 only
needs it when retraining for a faster link speed (Richard Zhu)
- Toggle i.MX95 core reset to align with PHY powerup (Richard Zhu)
- Set SYS_AUX_PWR_DET to work around i.MX95 ERR051624 erratum: in
some cases, the controller can't exit 'L23 Ready' through Beacon or
PERST# deassertion (Richard Zhu)
- Clear GEN3_ZRXDC_NONCOMPL to work around i.MX95 ERR051586 erratum:
controller can't meet 2.5 GT/s ZRX-DC timing when operating at 8
GT/s, causing timeouts in L1 (Richard Zhu)
- Wait for i.MX95 PLL lock before enabling controller (Richard Zhu)
- Save/restore i.MX95 LUT for suspend/resume (Richard Zhu)
Mobiveil PCIe controller driver:
- Return bool (not int) for link-up check in
mobiveil_pab_ops.link_up() and layerscape-gen4, mobiveil (Hans
Zhang)
NVIDIA Tegra194 PCIe controller driver:
- Create debugfs directory for 'aspm_state_cnt' only when
CONFIG_PCIEASPM is enabled, since there are no other entries (Hans
Zhang)
Qualcomm PCIe controller driver:
- Add OF support for parsing DT 'eq-presets-<N>gts' property for lane
equalization presets (Krishna Chaitanya Chundru)
- Read Maximum Link Width from the Link Capabilities register if DT
lacks 'num-lanes' property (Krishna Chaitanya Chundru)
- Add Physical Layer 64 GT/s Capability ID and register offsets for
8, 32, and 64 GT/s lane equalization registers (Krishna Chaitanya
Chundru)
- Add generic dwc support for configuring lane equalization presets
(Krishna Chaitanya Chundru)
- Add DT and driver support for PCIe on IPQ5018 SoC (Nitheesh Sekar)
Renesas R-Car PCIe controller driver:
- Describe endpoint BAR 4 as being fixed size (Jerome Brunet)
- Document how to obtain R-Car V4H (r8a779g0) controller firmware
(Yoshihiro Shimoda)
Rockchip PCIe controller driver:
- Reorder rockchip_pci_core_rsts because
reset_control_bulk_deassert() deasserts in reverse order, to fix a
link training regression (Jensen Huang)
- Mark RK3399 as being capable of raising INTx interrupts (Niklas
Cassel)
Rockchip DesignWare PCIe controller driver:
- Check only PCIE_LINKUP, not LTSSM status, to determine whether the
link is up (Shawn Lin)
- Increase N_FTS (used in L0s->L0 transitions) and enable ASPM L0s
for Root Complex and Endpoint modes (Shawn Lin)
- Hide the broken ATS Capability in rockchip_pcie_ep_init() instead
of rockchip_pcie_ep_pre_init() so it stays hidden after PERST#
resets non-sticky registers (Shawn Lin)
- Call phy_power_off() before phy_exit() in rockchip_pcie_phy_deinit()
(Diederik de Haas)
Synopsys DesignWare PCIe controller driver:
- Set PORT_LOGIC_LINK_WIDTH to one lane to make initial link training
more robust; this will not affect the intended link width if all
lanes are functional (Wenbin Yao)
- Return bool (not int) for link-up check in dw_pcie_ops.link_up()
and armada8k, dra7xx, dw-rockchip, exynos, histb, keembay,
keystone, kirin, meson, qcom, qcom-ep, rcar_gen4, spear13xx,
tegra194, uniphier, visconti (Hans Zhang)
- Add debugfs support for exposing DWC device-specific PTM context
(Manivannan Sadhasivam)
TI J721E PCIe driver:
- Make j721e buildable as a loadable and removable module (Siddharth
Vadapalli)
- Fix j721e host/endpoint dependencies that result in link failures
in some configs (Arnd Bergmann)
Device tree bindings:
- Add qcom DT binding for 'global' interrupt (PCIe controller and
link-specific events) for ipq8074, ipq8074-gen3, ipq6018, sa8775p,
sc7280, sc8180x sdm845, sm8150, sm8250, sm8350 (Manivannan
Sadhasivam)
- Add qcom DT binding for 8 MSI SPI interrupts for msm8998, ipq8074,
ipq8074-gen3, ipq6018 (Manivannan Sadhasivam)
- Add dw rockchip DT binding for rk3576 and rk3562 (Kever Yang)
- Correct indentation and style of examples in brcm,stb-pcie,
cdns,cdns-pcie-ep, intel,keembay-pcie-ep, intel,keembay-pcie,
microchip,pcie-host, rcar-pci-ep, rcar-pci-host, xilinx-versal-cpm
(Krzysztof Kozlowski)
- Convert Marvell EBU (dove, kirkwood, armada-370, armada-xp) and
armada8k from text to schema DT bindings (Rob Herring)
- Remove obsolete .txt DT bindings for content that has been moved to
schemas (Rob Herring)
- Add qcom DT binding for MHI registers in IPQ5332, IPQ6018, IPQ8074
and IPQ9574 (Varadarajan Narayanan)
- Convert v3,v360epc-pci from text to DT schema binding (Rob Herring)
- Change microchip,pcie-host DT binding to be 'dma-noncoherent' since
PolarFire may be configured that way (Conor Dooley)
Miscellaneous:
- Drop 'pci' suffix from intel_mid_pci.c filename to match similar
files (Andy Shevchenko)
- All platforms with PCI have an MMU, so add PCI Kconfig dependency
on MMU to simplify build testing and avoid inadvertent build
regressions (Arnd Bergmann)
- Update Krzysztof Wilczyński's email address in MAINTAINERS
(Krzysztof Wilczyński)
- Update Manivannan Sadhasivam's email address in MAINTAINERS
(Manivannan Sadhasivam)"
* tag 'pci-v6.16-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci: (147 commits)
MAINTAINERS: Update Manivannan Sadhasivam email address
PCI: j721e: Fix host/endpoint dependencies
PCI: j721e: Add support to build as a loadable module
PCI: cadence-ep: Introduce cdns_pcie_ep_disable() helper for cleanup
PCI: cadence-host: Introduce cdns_pcie_host_disable() helper for cleanup
PCI: cadence: Add support to build pcie-cadence library as a kernel module
MAINTAINERS: Update Krzysztof Wilczyński email address
PCI: Remove unnecessary linesplit in __pci_setup_bridge()
PCI: WARN (not BUG()) when we fail to assign optional resources
PCI: Remove unused pci_printk()
PCI: qcom: Replace PERST# sleep time with proper macro
PCI: dw-rockchip: Replace PERST# sleep time with proper macro
PCI: host-common: Convert to library for host controller drivers
PCI/ERR: Remove misleading TODO regarding kernel panic
PCI: cadence: Remove duplicate message code definitions
PCI: endpoint: Align pci_epc_set_msix(), pci_epc_ops::set_msix() nr_irqs encoding
PCI: endpoint: Align pci_epc_set_msi(), pci_epc_ops::set_msi() nr_irqs encoding
PCI: endpoint: Align pci_epc_get_msix(), pci_epc_ops::get_msix() return value encoding
PCI: endpoint: Align pci_epc_get_msi(), pci_epc_ops::get_msi() return value encoding
PCI: cadence-ep: Correct PBA offset in .set_msix() callback
...
The comment in pm_runtime_blocked() is acutally wrong: power.last_status
is not a bit field. Its data type is an enum and so one can reasonably
assume that partial updates of it will not be observed.
Accordingly, pm_runtime_blocked() can be converted to a static inline
function and the related locking overhead can be eliminated, so long
as it is only used in system suspend/resume code paths because
power.last_status is not expected to be updated concurrently while
that code is running.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://patch.msgid.link/1923449.tdWV9SEqCh@rjwysocki.net
The check before setting power.must_resume in device_suspend_noirq()
does not take power.child_count into account, but it should do that, so
use pm_runtime_need_not_resume() in it for this purpose and adjust the
comment next to it accordingly.
Fixes: 107d47b2b9 ("PM: sleep: core: Simplify the SMART_SUSPEND flag handling")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://patch.msgid.link/3353728.44csPzL39Z@rjwysocki.net
Introduce a new helper function called pm_runtime_blocked()
for checking the power.last_status value indicating whether or not
enabling runtime PM for the given device has been blocked (which
happens in the "prepare" phase of system-wide suspend if runtime
PM is disabled for the given device at that point).
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://patch.msgid.link/4632087.LvFx2qVVIh@rjwysocki.net
If device_prepare() runs on a device that has never had runtime
PM enabled so far, it may reasonably assume that runtime PM will
not be enabled for that device during the system suspend-resume
cycle currently in progress, but this has never been guaranteed.
To verify this assumption, make device_prepare() arrange for
triggering a device warning accompanied by a call trace dump if
runtime PM is enabled for such a device after it has returned.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://patch.msgid.link/6131109.lOV4Wx5bFT@rjwysocki.net
There are only two callers of __pm_runtime_disable(), one of which is
device_suspend_late() and the other is pm_runtime_disable() that has
its own kerneldoc comment and there are no plans to add any more of
them. Since they use different values of the __pm_runtime_disable()
second parameter, the actual code behavior is different in each case,
but it is all documented in the __pm_runtime_disable() kerneldoc comment
which is not particularly straightforward.
For this reason, move the information from the __pm_runtime_disable()
kerneldoc comment to the pm_runtime_disable() one and into a separate
comment in device_suspend_late() and remove the __pm_runtime_disable()
kerneldoc comment altogether.
No functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://patch.msgid.link/12617588.O9o76ZdvQC@rjwysocki.net
Add __pm_runtime_put_autosuspend() that replaces
pm_runtime_put_autosuspend() for new users. The intent is to later
re-purpose pm_runtime_put_autosuspend() to also mark the device's last
busy stamp---which is what the vast majority of users actually need.
This is also described in pm_runtime_put_autosuspend() documentation.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Rafael J. Wysocki
Brian Norris
Sakari Ailus
Linus Torvalds
Bence Csókás
Alex Williamson