The sysfs_emit() and sysfs_emit_at() functions were introduced to make
it less ambiguous which function is preferred when writing to the output
buffer in a device attribute's "show" callback [1].
Convert the PCI sysfs object "show" functions from sprintf(), snprintf()
and scnprintf() to sysfs_emit() and sysfs_emit_at() accordingly, as the
latter is aware of the PAGE_SIZE buffer and correctly returns the number
of bytes written into the buffer.
No functional change intended.
[1] Documentation/filesystems/sysfs.rst
Related commit: ad025f8e46 ("PCI/sysfs: Use sysfs_emit() and
sysfs_emit_at() in "show" functions").
Link: https://lore.kernel.org/r/20210603000112.703037-2-kw@linux.com
Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Previously ASPM L1 Substates control registers (CTL1 and CTL2) weren't
saved and restored during suspend/resume leading to L1 Substates
configuration being lost post-resume.
Save the L1 Substates control registers so that the configuration is
retained post-resume.
Link: https://lore.kernel.org/r/20201024190442.871-1-vidyas@nvidia.com
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Previously we computed L1.2 parameters in the enumeration path, saved them
in struct pcie_link_state.l1ss, and programmed them into the devices
whenever we enabled or disabled L1.2 on the link. But these parameters are
constant and don't need to be updated when enabling/disabling L1.2.
Compute and program the L1.2 parameters once during enumeration and remove
the struct pcie_link_state.l1ss member. No functional change intended.
[bhelgaas: rework to program L1.2 parameters during enumeration]
Link: https://lore.kernel.org/r/20201015193039.12585-13-helgaas@kernel.org
Signed-off-by: Saheed O. Bolarinwa <refactormyself@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Previously we stored the L1SS Capabilities value in the struct
aspm_register_info.
We only need this information in one place, so read it there and remove
struct aspm_register_info completely, since it's now empty. No functional
change intended.
[bhelgaas: split up, don't cache l1ss_cap in pci_dev]
Link: https://lore.kernel.org/r/20201015193039.12585-12-helgaas@kernel.org
Signed-off-by: Saheed O. Bolarinwa <refactormyself@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
aspm_calc_l1ss_info() needs only the L1SS Capabilities. It doesn't need
anything else from struct aspm_register_info, so pass only the Capabilities
value. No functional change intended.
Link: https://lore.kernel.org/r/20201015193039.12585-11-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Previously we stored the L1SS Control 1 register in the struct
aspm_register_info.
We only need this information in one place, so read it there and remove it
from struct aspm_register_info. No functional change intended.
[bhelgaas: split ctl1/ctl2]
Link: https://lore.kernel.org/r/20201015193039.12585-10-helgaas@kernel.org
Signed-off-by: Saheed O. Bolarinwa <refactormyself@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Save the L1 Substates Capability pointer in struct pci_dev. Then we don't
have to keep track of it in the struct aspm_register_info and struct
pcie_link_state, which makes the code easier to read. No functional change
intended.
[bhelgaas: split to a separate patch]
Link: https://lore.kernel.org/r/20201015193039.12585-8-helgaas@kernel.org
Signed-off-by: Saheed O. Bolarinwa <refactormyself@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Previously we stored L0s and L1 Exit Latency information from the Link
Capabilities register in the struct aspm_register_info.
We only need these latencies when we already have the Link Capabilities
values, so use those directly and remove the latencies from struct
aspm_register_info. No functional change intended.
Link: https://lore.kernel.org/r/20201015193039.12585-7-helgaas@kernel.org
Signed-off-by: Saheed O. Bolarinwa <refactormyself@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Previously we stored the "ASPM Control" bits from the Link Control register
in the struct aspm_register_info.
Read PCI_EXP_LNKCTL directly when needed. This means we can use the
PCI_EXP_LNKCTL_ASPM_* bits directly instead of the similar but different
PCIE_LINK_STATE_* bits. No functional change intended.
[bhelgaas: drop get_aspm_enable() and read LNKCTL once directly]
Link: https://lore.kernel.org/r/20201015193039.12585-6-helgaas@kernel.org
Signed-off-by: Saheed O. Bolarinwa <refactormyself@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Previously we stored the "ASPM Support" field from the Link Capabilities
register in the struct aspm_register_info.
Read the Link Capabilities directly when needed and remove it from the
struct aspm_register_info. No functional change intended.
[bhelgaas: remove pci_dev cached copy since LNKCAP isn't truly read-only,
add PCI_EXP_LNKCAP_ASPM_L0S & PCI_EXP_LNKCAP_ASPM_L1, check them directly
instead of adding aspm_support()]
Link: https://lore.kernel.org/r/20201015193039.12585-5-helgaas@kernel.org
Signed-off-by: Saheed O. Bolarinwa <refactormyself@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Other users of link->pdev and link->downstream, e.g., pcie_aspm_cap_init(),
pcie_config_aspm_l1ss(), and pcie_config_aspm_link(), use "parent" and
"child" as local names.
Do the same in aspm_calc_l1ss_info() for readability. No functional change
intended.
Link: https://lore.kernel.org/r/20201015193039.12585-4-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
pcie_get_aspm_reg() mostly reads ASPM-related registers, but in some cases
it also updates the value read from PCI_L1SS_CAP based on LTR properties.
Move this update to the point where the value is used to make the code more
readable.
No functional change intended, although previously we could clear
PCI_L1SS_CAP_ASPM_L1_2 for both ends of the link, and now we'll only do it
for the downstream end of a link. This shouldn't matter because we always
test that bit by ANDing l1ss_cap for the upstream and downstream ends.
Link: https://lore.kernel.org/r/20201015193039.12585-3-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
When I cat ASPM parameter 'policy' by sysfs, it displays as follows. Add a
newline for easy reading. Other sysfs attributes already include a
newline.
[root@localhost ~]# cat /sys/module/pcie_aspm/parameters/policy
[default] performance powersave powersupersave [root@localhost ~]#
Fixes: 7d715a6c1a ("PCI: add PCI Express ASPM support")
Link: https://lore.kernel.org/r/1594972765-10404-1-git-send-email-wangxiongfeng2@huawei.com
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
7d715a6c1a ("PCI: add PCI Express ASPM support") added the ability for
Linux to enable ASPM, but for some undocumented reason, it didn't enable
ASPM on links where the downstream component is a PCIe-to-PCI/PCI-X Bridge.
Remove this exclusion so we can enable ASPM on these links.
The Dell OptiPlex 7080 mentioned in the bugzilla has a TI XIO2001
PCIe-to-PCI Bridge. Enabling ASPM on the link leading to it allows the
Intel SoC to enter deeper Package C-states, which is a significant power
savings.
[bhelgaas: commit log]
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=207571
Link: https://lore.kernel.org/r/20200505173423.26968-1-kai.heng.feng@canonical.com
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
When the UEFI/BIOS or bootloader has not initialised a PCIe device we would
get the following message:
kern.warning: pci 0000:00:01.0: ASPM: current common clock configuration is broken, reconfiguring
"warning" and "broken" are slightly misleading. On an embedded system it is
quite possible for the bootloader to avoid configuring PCIe devices if they
are not needed.
Downgrade the message to pci_info() and change "broken" to "inconsistent"
since we fix up the inconsistency in the code immediately following the
message (and emit an error if that fails).
Link: https://lore.kernel.org/r/20200323035530.11569-1-chris.packham@alliedtelesis.co.nz
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
In pcie_config_aspm_l1ss(), we cleared the wrong bits when enabling ASPM L1
Substates. Instead of the L1.x enable bits (PCI_L1SS_CTL1_L1SS_MASK, 0xf), we
cleared the Link Activation Interrupt Enable bit (PCI_L1SS_CAP_L1_PM_SS,
0x10).
Clear the L1.x enable bits before writing the new L1.x configuration.
[bhelgaas: changelog]
Fixes: aeda9adeba ("PCI/ASPM: Configure L1 substate settings")
Link: https://lore.kernel.org/r/1584093227-1292-1-git-send-email-yangyicong@hisilicon.com
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org # v4.11+
Previously, CONFIG_PCIEASPM_DEBUG enabled "link_state" and "clk_ctl" sysfs
files that controlled ASPM. We believe these files were rarely if ever
used.
We recently added sysfs ASPM controls that are always present, so the debug
code is no longer needed. Removing this debug code has been discussed for
quite some time, see e.g. [0].
Remove PCIEASPM_DEBUG and the related code.
[0] https://lore.kernel.org/lkml/20180727202619.GD173328@bhelgaas-glaptop.roam.corp.google.com/
Link: https://lore.kernel.org/r/ec935d8e-c084-3938-f1d1-748617596b25@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Add sysfs attributes to Endpoints and other Upstream Ports to control ASPM,
Clock PM, and L1 PM Substates. The new attributes are:
/sys/devices/pci*/.../link/clkpm
/sys/devices/pci*/.../link/l0s_aspm
/sys/devices/pci*/.../link/l1_aspm
/sys/devices/pci*/.../link/l1_1_aspm
/sys/devices/pci*/.../link/l1_2_aspm
/sys/devices/pci*/.../link/l1_1_pcipm
/sys/devices/pci*/.../link/l1_2_pcipm
An attribute is only visible if both ends of the Link leading to the device
support the state. Writing y/1/on to the file enables the state; n/0/off
disables it.
These attributes can be used to tune the power/performance tradeoff for
individual devices.
[bhelgaas: commit log, rename directory to "link"]
Link: https://lore.kernel.org/r/b1c83f8a-9bf6-eac5-82d0-cf5b90128fbf@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Factor out getting the link associated with a pci_dev and use this helper
where appropriate. In addition this helper will be used in a subsequent
patch of this series.
Link: https://lore.kernel.org/r/19d33770-29de-a9af-4d85-f2b30269d383@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Previously Clock PM could not be re-enabled after being disabled by
pci_disable_link_state() because clkpm_capable was reset. Change this by
adding a clkpm_disable field similar to aspm_disable.
Link: https://lore.kernel.org/r/4e8a66db-7d53-4a66-c26c-f0037ffaa705@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Add support for disabling states L1.1 and L1.2 to pci_disable_link_state().
Allow separate control of ASPM and PCI PM L1 substates.
Link: https://lore.kernel.org/r/d81f8036-c236-6463-48e7-ebcdcda85bba@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The lifetime of the link_state structure (bridge->link_state) is not the
same as the lifetime of "bridge" itself. The link_state is allocated by
pcie_aspm_init_link_state() after children of the bridge have been
enumerated, and it is deallocated by pcie_aspm_exit_link_state() after all
children of the bridge (but not the bridge itself) have been removed.
Previously pcie_aspm_enabled() acquired aspm_lock to ensure that
link_state was not deallocated while we're looking at it. But the fact
that the caller of pcie_aspm_enabled() holds a reference to @pdev means
there's always at least one child of the bridge, which means link_state
can't be deallocated.
Remove the unnecessary locking in pcie_aspm_enabled().
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
- Consolidate _HPP & _HPX code in pci-acpi.h and remove unnecessary
struct hotplug_program_ops (Krzysztof Wilczynski)
- Fixup PCIe device types to remove the need for dev->has_secondary_link
(Mika Westerberg)
* pci/enumeration:
PCI: Get rid of dev->has_secondary_link flag
PCI: Make pcie_downstream_port() available outside of access.c
PCI/ACPI: Remove unnecessary struct hotplug_program_ops
PCI/ACPI: Move _HPP & _HPX functions to pci-acpi.c
PCI/ACPI: Rename _HPX structs from hpp_* to hpx_*
In some systems, the Device/Port Type in the PCI Express Capabilities
register incorrectly identifies upstream ports as downstream ports.
d0751b98df ("PCI: Add dev->has_secondary_link to track downstream PCIe
links") addressed this by adding pci_dev.has_secondary_link, which is set
for downstream ports. But this is confusing because pci_pcie_type()
sometimes gives the wrong answer, and it's not obvious that we should use
pci_dev.has_secondary_link instead.
Reduce the confusion by correcting the type of the port itself so that
pci_pcie_type() returns the actual type regardless of what the Device/Port
Type register claims it is. Update the users to call pci_pcie_type() and
pcie_downstream_port() accordingly, and remove pci_dev.has_secondary_link
completely.
Link: https://lore.kernel.org/linux-pci/20190703133953.GK128603@google.com/
Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20190822085553.62697-2-mika.westerberg@linux.intel.com
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Move ASPM definitions and function prototypes from include/linux/pci-aspm.h
to include/linux/pci.h so users only need to include <linux/pci.h>:
PCIE_LINK_STATE_L0S
PCIE_LINK_STATE_L1
PCIE_LINK_STATE_CLKPM
pci_disable_link_state()
pci_disable_link_state_locked()
pcie_no_aspm()
No functional changes intended.
Link: https://lore.kernel.org/r/20190827095620.11213-1-kw@linux.com
Signed-off-by: Krzysztof Wilczynski <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Add a function checking whether or not PCIe ASPM has been enabled for
a given device.
It will be used by the NVMe driver to decide how to handle the
device during system suspend.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Drivers may rely on pci_disable_link_state() having disabled certain
ASPM link states. If OS can't control ASPM then pci_disable_link_state()
turns into a no-op w/o informing the caller. The driver therefore may
falsely assume the respective ASPM link states are disabled.
Let pci_disable_link_state() propagate errors to the caller, enabling
the caller to react accordingly.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Transform wait code to a "do {} while (time_before())" loop as recommended
by reviewer. No functional change intended.
Signed-off-by: Stefan Mätje <stefan.maetje@esd.eu>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Due to an erratum in some Pericom PCIe-to-PCI bridges in reverse mode
(conventional PCI on primary side, PCIe on downstream side), the Retrain
Link bit needs to be cleared manually to allow the link training to
complete successfully.
If it is not cleared manually, the link training is continuously restarted
and no devices below the PCI-to-PCIe bridge can be accessed. That means
drivers for devices below the bridge will be loaded but won't work and may
even crash because the driver is only reading 0xffff.
See the Pericom Errata Sheet PI7C9X111SLB_errata_rev1.2_102711.pdf for
details. Devices known as affected so far are: PI7C9X110, PI7C9X111SL,
PI7C9X130.
Add a new flag, clear_retrain_link, in struct pci_dev. Quirks for affected
devices set this bit.
Note that pcie_retrain_link() lives in aspm.c because that's currently the
only place we use it, but this erratum is not specific to ASPM, and we may
retrain links for other reasons in the future.
Signed-off-by: Stefan Mätje <stefan.maetje@esd.eu>
[bhelgaas: apply regardless of CONFIG_PCIEASPM]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
CC: stable@vger.kernel.org
Factor out pcie_retrain_link() to use for Pericom Retrain Link quirk. No
functional change intended.
Signed-off-by: Stefan Mätje <stefan.maetje@esd.eu>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
CC: stable@vger.kernel.org
ASPM does not make use of the children or link LIST_HEADs declared in
struct pcie_link_state and defined in alloc_pcie_link_state(). Therefore,
remove these lists.
No functional change intended.
Signed-off-by: Frederick Lawler <fred@fredlawl.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
This reverts commit 17c9148736.
Rafael found that this commit broke the SD card reader in his
Acer Aspire S5. Details of the problem are in the bugzilla below.
Fixes: 17c9148736 ("PCI/ASPM: Do not initialize link state when aspm_disabled is set")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=201801
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Now that ASPM is configured for *all* PCIe devices at boot, a problem is
seen with systems that set the FADT NO_ASPM bit. This bit indicates that
the OS should not alter the ASPM state, but when
pcie_aspm_init_link_state() runs it only checks for !aspm_support_enabled.
This misses the ACPI_FADT_NO_ASPM case because that is setting
aspm_disabled.
The result is systems may hang at boot after 1302fcf; avoidable if they
boot with pcie_aspm=off (sets !aspm_support_enabled).
Fix this by having aspm_init_link_state() check for either
!aspm_support_enabled or acpm_disabled.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=201001
Fixes: 1302fcf0d0 ("PCI: Configure *all* devices, not just hot-added ones")
Signed-off-by: Patrick Talbert <ptalbert@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Upon removal of the last device on a bus, the link_state of the bridge
leading to that bus is sought to be torn down by having pci_stop_dev()
call pcie_aspm_exit_link_state().
When ASPM was originally introduced by commit 7d715a6c1a ("PCI: add
PCI Express ASPM support"), it determined whether the device being
removed is the last one by calling list_empty() on the bridge's
subordinate devices list. That didn't work because the device is only
removed from the list slightly later in pci_destroy_dev().
Commit 3419c75e15 ("PCI: properly clean up ASPM link state on device
remove") attempted to fix it by calling list_is_last(), but that's not
correct either because it checks whether the device is at the *end* of
the list, not whether it's the last one *left* in the list. If the user
removes the device which happens to be at the end of the list via sysfs
but other devices are preceding the device in the list, the link_state
is torn down prematurely.
The real fix is to move the invocation of pcie_aspm_exit_link_state() to
pci_destroy_dev() and reinstate the call to list_empty(). Remove a
duplicate check for dev->bus->self because pcie_aspm_exit_link_state()
already contains an identical check.
Fixes: 7d715a6c1a ("PCI: add PCI Express ASPM support")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: stable@vger.kernel.org # v2.6.26
The sysfs_match_string() helper returns index of the matching string in an
array. Use it in pcie_aspm_set_policy() to simplify the code.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[bhelgaas: squash sysfs_match_string() fix into original patch for issue
Reported-by: Heiner Kallweit <hkallweit1@gmail.com>]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
When in the ASPM L1.0 state (but not the PCI-PM L1.0 state), the most
recent LTR value and the LTR_L1.2_THRESHOLD determines whether the link
enters the L1.2 substate.
If we don't have LTR enabled, prevent the use of ASPM L1.2.
PCI-PM L1.2 may still be used because it doesn't depend on
LTR_L1.2_THRESHOLD (see PCIe r4.0, sec 5.5.1).
Tested-by: Srinath Mannam <srinath.mannam@broadcom.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
- use PCI_EXP_DEVCTL2_COMP_TIMEOUT in rapidio/tsi721 (Bjorn Helgaas)
- remove possible NULL pointer dereference in of_pci_bus_find_domain_nr()
(Shawn Lin)
- report quirk timings with dev_info (Bjorn Helgaas)
- report quirks that take longer than 10ms (Bjorn Helgaas)
- add and use Altera Vendor ID (Johannes Thumshirn)
- tidy Makefiles and comments (Bjorn Helgaas)
* pci/misc:
PCI: Always define the of_node helpers
PCI: Tidy comments
PCI: Tidy Makefiles
mcb: Add Altera PCI ID to mcb-pci
PCI: Add Altera vendor ID
PCI: Report quirks that take more than 10ms
PCI: Report quirk timings with pci_info() instead of pr_debug()
PCI: Fix NULL pointer dereference in of_pci_bus_find_domain_nr()
rapidio/tsi721: use PCI_EXP_DEVCTL2_COMP_TIMEOUT macro
Remove pointless comments that tell us the file name, remove blank line
comments, follow multi-line comment conventions. No functional change
intended.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Previously we emitted a warning if we tried to configure common clock mode
the link was already configured to common clock mode by the UEFI BIOS.
Bail out silently in that case instead of emitting the warning:
pci 0004:00:00.0: ASPM: Could not configure common clock
Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
[bhelgaas: changelog]
Signed-off-by: Bjorn Helgaas <helgaas@kernel.org>
aspm_calc_l1ss_info() computes l1_2_threshold in microseconds as:
l1_2_threshold = 2 + 4 + t_common_mode + t_power_on;
where t_common_mode is at most 255us:
PCI_L1SS_CAP_CM_RESTORE_TIME 0x0000ff00 <-- 8 bits; <256us
and t_power_on is at most 31 * 100us = 3100us:
PCI_L1SS_CAP_P_PWR_ON_VALUE 0x00f80000 <-- 5 bits; <32
PCI_L1SS_CAP_P_PWR_ON_SCALE 0x00030000 <-- *2us, *10us, or *100us
So l1_2_threshold is at most 2 + 4 + 255 + 3100 = 3361, which means
threshold_ns is at most 3361 * 1000 = 3361000, which easily fits in a
u32.
Declare threshold_ns as u32, not u64. This fixes a Coverity warning.
Addresses-Coverity-ID: 1462501
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
[bhelgaas: changelog]
Signed-off-by: Bjorn Helgaas <helgaas@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
* pci/misc:
PCI: Add dummy pci_irqd_intx_xlate() for CONFIG_PCI=n build
PCI: Add wrappers for dev_printk()
PCI: Remove unnecessary messages for memory allocation failures
PCI: Add #defines for Completion Timeout Disable feature
hinic: Replace PCI pool old API
net: e100: Replace PCI pool old API
block: DAC960: Replace PCI pool old API
MAINTAINERS: Include more PCI files
PCI: Remove unneeded kallsyms include
powerpc/pci: Unroll two pass loop when scanning bridges
powerpc/pci: Use for_each_pci_bridge() helper
Add PCI-specific dev_printk() wrappers and use them to simplify the code
slightly. No functional change intended.
Signed-off-by: Frederick Lawler <fred@fredlawl.com>
[bhelgaas: squash into one patch]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Per PCIe r3.1, sec 5.5.1, LTR_L1.2_THRESHOLD determines whether we enter
the L1.2 Link state: if L1.2 is enabled and downstream devices have
reported that they can tolerate latency of at least LTR_L1.2_THRESHOLD, we
must enter L1.2 when CLKREQ# is de-asserted.
The implication is that LTR_L1.2_THRESHOLD is the time required to
transition the Link from L0 to L1.2 and back to L0, and per sec 5.5.3.3.1,
Figures 5-16 and 5-17, it appears that the absolute minimum time for those
transitions would be T(POWER_OFF) + T(L1.2) + T(POWER_ON) + T(COMMONMODE).
Therefore, compute LTR_L1.2_THRESHOLD as:
2us T(POWER_OFF)
+ 4us T(L1.2)
+ T(POWER_ON)
+ T(COMMONMODE)
= LTR_L1.2_THRESHOLD
Previously we set LTR_L1.2_THRESHOLD to a fixed value of 163840ns
(163.84us):
#define LTR_L1_2_THRESHOLD_BITS ((1 << 21) | (1 << 23) | (1 << 30))
((1 << 21) | (1 << 23) | (1 << 30)) = 0x40a00000
LTR_L1.2_THRESHOLD_Value = (0x40a00000 & 0x03ff0000) >> 16 = 0xa0 = 160
LTR_L1.2_THRESHOLD_Scale = (0x40a00000 & 0xe0000000) >> 29 = 0x2 (* 1024ns)
LTR_L1.2_THRESHOLD = 160 * 1024ns = 163840ns
Obviously this doesn't account for the circuit characteristics of different
implementations.
Note that while firmware may enable LTR, Linux itself currently does not
enable LTR. When L1.2 is enabled but LTR is not, LTR_L1.2_THRESHOLD is
ignored and we always enter L1.2 when it is enabled and CLKREQ# is
de-asserted. So this patch should not have any effect unless firmware
enables LTR.
Fixes: f1f0366dd6 ("PCI/ASPM: Calculate and save the L1.2 timing parameters")
Link: https://www.coreboot.org/pipermail/coreboot-gerrit/2015-March/021134.html
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Vidya Sagar <vidyas@nvidia.com>
Cc: Kenji Chen <kenji.chen@intel.com>
Cc: Patrick Georgi <pgeorgi@google.com>
Cc: Rajat Jain <rajatja@google.com>
Summary of modules changes for the 4.15 merge window:
- Treewide module_param_call() cleanup, fix up set/get function
prototype mismatches, from Kees Cook
- Minor code cleanups
Signed-off-by: Jessica Yu <jeyu@kernel.org>
-----BEGIN PGP SIGNATURE-----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=c8vb
-----END PGP SIGNATURE-----
Merge tag 'modules-for-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux
Pull module updates from Jessica Yu:
"Summary of modules changes for the 4.15 merge window:
- treewide module_param_call() cleanup, fix up set/get function
prototype mismatches, from Kees Cook
- minor code cleanups"
* tag 'modules-for-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
module: Do not paper over type mismatches in module_param_call()
treewide: Fix function prototypes for module_param_call()
module: Prepare to convert all module_param_call() prototypes
kernel/module: Delete an error message for a failed memory allocation in add_module_usage()
Krzysztof Wilczyński