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path: root/drivers/pci/pcie/pme.c (follow)
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2019-05-09PCI/PME: Replace dev_printk(KERN_DEBUG) with dev_info()Frederick Lawler1-4/+6
Replace dev_printk(KERN_DEBUG) with dev_info() or dev_err() to be more consistent with other logging. These could be converted to dev_dbg(), but that depends on CONFIG_DYNAMIC_DEBUG and DEBUG, and we want most of these messages to *always* be in the dmesg log. Also, use dev_fmt() to add the service name. Example output change: - pcieport 0000:80:10.0: Signaling PME with IRQ ... + pcieport 0000:80:10.0: PME: Signaling with IRQ ... Link: https://lore.kernel.org/lkml/20190509141456.223614-3-helgaas@kernel.org Signed-off-by: Frederick Lawler <fred@fredlawl.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Keith Busch <keith.busch@intel.com>
2019-03-01PCI/PME: Fix possible use-after-free on removeSven Van Asbroeck1-0/+1
In remove(), ensure that the PME work cannot run after kfree() is called. Otherwise, this could result in a use-after-free. This issue was detected with the help of Coccinelle. Signed-off-by: Sven Van Asbroeck <TheSven73@gmail.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: Sinan Kaya <okaya@kernel.org> Cc: Frederick Lawler <fred@fredlawl.com> Cc: Mika Westerberg <mika.westerberg@linux.intel.com> Cc: Keith Busch <keith.busch@intel.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-02-28PCI/PME: Fix hotplug/sysfs remove deadlock in pcie_pme_remove()Rafael J. Wysocki1-7/+15
Dongdong reported a deadlock triggered by a hotplug event during a sysfs "remove" operation: pciehp 0000:00:0c.0:pcie004: Slot(0-1): Link Up # echo 1 > 0000:00:0c.0/remove PME and hotplug share an MSI/MSI-X vector. The sysfs "remove" side is: remove_store pci_stop_and_remove_bus_device_locked pci_lock_rescan_remove pci_stop_and_remove_bus_device ... pcie_pme_remove pcie_pme_suspend synchronize_irq # wait for hotplug IRQ handler pci_unlock_rescan_remove The hotplug side is: pciehp_ist pciehp_handle_presence_or_link_change pciehp_configure_device pci_lock_rescan_remove # wait for pci_unlock_rescan_remove() INFO: task bash:10913 blocked for more than 120 seconds. # ps -ax |grep D PID TTY STAT TIME COMMAND 10913 ttyAMA0 Ds+ 0:00 -bash 14022 ? D 0:00 [irq/745-pciehp] # cat /proc/14022/stack __switch_to+0x94/0xd8 pci_lock_rescan_remove+0x20/0x28 pciehp_configure_device+0x30/0x140 pciehp_handle_presence_or_link_change+0x324/0x458 pciehp_ist+0x1dc/0x1e0 # cat /proc/10913/stack __switch_to+0x94/0xd8 synchronize_irq+0x8c/0xc0 pcie_pme_suspend+0xa4/0x118 pcie_pme_remove+0x20/0x40 pcie_port_remove_service+0x3c/0x58 ... pcie_port_device_remove+0x2c/0x48 pcie_portdrv_remove+0x68/0x78 pci_device_remove+0x48/0x120 ... pci_stop_bus_device+0x84/0xc0 pci_stop_and_remove_bus_device_locked+0x24/0x40 remove_store+0xa4/0xb8 dev_attr_store+0x44/0x60 sysfs_kf_write+0x58/0x80 It is incorrect to call pcie_pme_suspend() from pcie_pme_remove() for two reasons. First, pcie_pme_suspend() calls synchronize_irq(), which will wait for the native hotplug interrupt handler as well as for the PME one, because they share one IRQ (as per the spec). That may deadlock if hotplug is signaled while pcie_pme_remove() is running and the latter calls pci_lock_rescan_remove() before the former. Second, if pcie_pme_suspend() figures out that wakeup needs to be enabled for the port, it will return without disabling the interrupt as expected by pcie_pme_remove() which was overlooked by commit c7b5a4e6e8fb ("PCI / PM: Fix native PME handling during system suspend/resume"). To fix that, rework pcie_pme_remove() to disable the PME interrupt, clear its status and prevent the PME worker function from re-enabling it before calling free_irq() on it, which should be sufficient. Fixes: c7b5a4e6e8fb ("PCI / PM: Fix native PME handling during system suspend/resume") Link: https://lore.kernel.org/linux-pci/c7697e7c-e1af-13e4-8491-0a3996e6ab5d@huawei.com Reported-by: Dongdong Liu <liudongdong3@huawei.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> [bhelgaas: add URL and deadlock details from Dongdong] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2019-02-14Revert "PCI/PME: Implement runtime PM callbacks"Mika Westerberg1-27/+0
This reverts commit 0e157e52860441cb26051f131dd0b5ae3187a07b. Heiner reported that the commit in question prevents his network adapter from triggering PME and waking up when network cable is plugged. The commit tried to prevent root port waking up from D3cold immediately but looks like disabing root port PME interrupt is not the right way to fix that issue so revert it now. The patch following proposes an alternative solution to that issue. Link: https://bugzilla.kernel.org/show_bug.cgi?id=202103 Fixes: 0e157e528604 ("PCI/PME: Implement runtime PM callbacks") Reported-by: Heiner Kallweit <hkallweit1@gmail.com> Tested-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> CC: stable@vger.kernel.org # v4.20+
2018-10-02PCI/PME: Implement runtime PM callbacksMika Westerberg1-0/+27
Basically we need to do the same steps than what we do when system sleep is entered and disable PME interrupt when the root port is runtime suspended. This prevents spurious wakeups immediately when the port is transitioned into D3cold. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-09-20PCI: portdrv: Initialize service drivers directlyKeith Busch1-2/+1
The PCI port driver saves the PCI state after initializing the device with the applicable service devices. This was, however, before the service drivers were even registered because PCI probe happens before the device_initcall initialized those service drivers. The config space state that the services set up were not being saved. The end result would cause PCI devices to not react to events that the drivers think they did if the PCI state ever needed to be restored. Fix this by changing the service drivers from using the init calls to having the portdrv driver calling the services directly. This will get the state saved as desired, while making the relationship between the port driver and the services under it more explicit in the code. Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Sinan Kaya <okaya@kernel.org>
2018-03-09PCI/portdrv: Merge pcieport_if.h into portdrv.hBjorn Helgaas1-1/+0
pcieport_if.h contained the interfaces to register port service driver, e.g., pcie_port_service_register(). portdrv.h contained internal data structures of the port driver. I don't think it's worth keeping those files separate, since both headers and their users are all inside the PCI core. Merge pcieport_if.h directly in drivers/pci/pcie/portdrv.h and update the users to include that instead. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2018-02-22PCI/portdrv: Move pcieport_if.h to drivers/pci/pcie/Frederick Lawler1-1/+1
Move pcieport_if.h from include/linux to drivers/pci/pcie/pcieport_if.h because the interfaces there are only used by the PCI core. Replace all uses of #include<linux/pcieport_if.h> with relative paths to the new file location, e.g., #include "../pcieport_if.h" Signed-off-by: Frederick Lawler <fred@fredlawl.com> Signed-off-by: Bjorn Helgaas <helgaas@kernel.org>
2018-02-01Merge branch 'pci/spdx' into nextBjorn Helgaas1-4/+1
* pci/spdx: PCI: Add SPDX GPL-2.0+ to replace implicit GPL v2 or later statement PCI: Add SPDX GPL-2.0+ to replace GPL v2 or later boilerplate PCI: Add SPDX GPL-2.0 to replace COPYING boilerplate PCI: Add SPDX GPL-2.0 to replace GPL v2 boilerplate PCI: Add SPDX GPL-2.0 when no license was specified
2018-01-28PCI: Add SPDX GPL-2.0 to replace GPL v2 boilerplateBjorn Helgaas1-4/+1
Add SPDX GPL-2.0 to all PCI files that specified the GPL version 2 license. Remove the boilerplate GPL version 2 language, relying on the assertion in b24413180f56 ("License cleanup: add SPDX GPL-2.0 license identifier to files with no license") that the SPDX identifier may be used instead of the full boilerplate text. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-18PCI: Add wrappers for dev_printk()Frederick Lawler1-3/+3
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>
2017-11-07PCI/PME: Handle invalid data when reading Root StatusQiang1-1/+4
PCIe PME and native hotplug share the same interrupt number, so hotplug interrupts are also processed by PME. In some cases, e.g., a Link Down interrupt, a device may be present but unreachable, so when we try to read its Root Status register, the read fails and we get all ones data (0xffffffff). Previously, we interpreted that data as PCI_EXP_RTSTA_PME being set, i.e., "some device has asserted PME," so we scheduled pcie_pme_work_fn(). This caused an infinite loop because pcie_pme_work_fn() tried to handle PME requests until PCI_EXP_RTSTA_PME is cleared, but with the link down, PCI_EXP_RTSTA_PME can't be cleared. Check for the invalid 0xffffffff data everywhere we read the Root Status register. 1469d17dd341 ("PCI: pciehp: Handle invalid data when reading from non-existent devices") added similar checks in the hotplug driver. Signed-off-by: Qiang Zheng <zhengqiang10@huawei.com> [bhelgaas: changelog, also check in pcie_pme_work_fn(), use "~0" to follow other similar checks] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2017-07-13PCI / PM: Fix native PME handling during system suspend/resumeRafael J. Wysocki1-22/+13
Commit 76cde7e49590 (PCI / PM: Make PCIe PME interrupts wake up from suspend-to-idle) went too far with preventing pcie_pme_work_fn() from clearing the root port's PME Status and re-enabling the PME interrupt which should be done for PMEs to work correctly after system resume. The failing scenario is as follows: 1. pcie_pme_suspend() finds that the PME IRQ should be designated for system wakeup, so it calls enable_irq_wake() and then sets data->suspend_level to PME_SUSPEND_WAKEUP. 2. PME interrupt happens at this point. 3. pcie_pme_irq() runs, disables the PME interrupt and queues up the execution of pcie_pme_work_fn(). 4. pcie_pme_work_fn() runs before pcie_pme_resume() and breaks out of the loop right away, because data->suspend_level is not PME_SUSPEND_NONE, and it doesn't re-enable the PME interrupt for the same reason. 5. pcie_pme_resume() runs and simply calls disable_irq_wake() without re-enabling the PME interrupt (because data->suspend_level is not PME_SUSPEND_NONE), so the PME interrupt remains disabled and the PME Status remains set. To fix this notice that there is no reason why pcie_pme_work_fn() should behave in a special way during system resume if the PME interrupt is not disabled by pcie_pme_suspend() and partially revert commit 76cde7e49590 and restore the previous (and correct) behavior of pcie_pme_work_fn(). Fixes: 76cde7e49590 (PCI / PM: Make PCIe PME interrupts wake up from suspend-to-idle) Reported-and-tested-by: Naresh Solanki <naresh.solanki@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com>
2017-06-28PM / core: Drop run_wake flag from struct dev_pm_infoRafael J. Wysocki1-1/+1
The run_wake flag in struct dev_pm_info is used to indicate whether or not the device is capable of generating remote wakeup signals at run time (or in the system working state), but the distinction between runtime remote wakeup and system wakeup signaling has always been rather artificial. The only practical reason for it to exist at the core level was that ACPI and PCI treated those two cases differently, but that's not the case any more after recent changes. For this reason, get rid of the run_wake flag and, when applicable, use device_set_wakeup_capable() and device_can_wakeup() instead of device_set_run_wake() and device_run_wake(), respectively. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com>
2017-06-28PCI / PM: Drop pme_interrupt flag from struct pci_devRafael J. Wysocki1-8/+6
The pme_interrupt flag in struct pci_dev is set when PMEs generated by the device are going to be signaled via root port PME interrupts. Ironically enough, that information is only used by the code setting up device wakeup through ACPI which returns as soon as it sees the pme_interrupt flag set while setting up "remote runtime wakeup". That is questionable, however, because in theory there may be PCIe devices using out-of-band PME signaling under root ports handled by the native PME code or devices requiring wakeup power setup to be carried out by AML. For such devices, ACPI wakeup should be invoked regardless of whether or not native PME signaling is used in general. For this reason, drop the pme_interrupt flag and rework the code using it which then allows the ACPI-based device wakeup handling in PCI to be consolidated to use one code path for both "runtime remote wakeup" and system wakeup (from sleep states). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com>
2017-02-15PCI/PME: Restore pcie_pme_driver.removeYinghai Lu1-0/+12
In addition to making PME non-modular, d7def2040077 ("PCI/PME: Make explicitly non-modular") removed the pcie_pme_driver .remove() method, pcie_pme_remove(). pcie_pme_remove() freed the PME IRQ that was requested in pci_pme_probe(). The fact that we don't free the IRQ after d7def2040077 causes the following crash when removing a PCIe port device via /sys: ------------[ cut here ]------------ kernel BUG at drivers/pci/msi.c:370! invalid opcode: 0000 [#1] SMP Modules linked in: CPU: 1 PID: 14509 Comm: sh Tainted: G W 4.8.0-rc1-yh-00012-gd29438d RIP: 0010:[<ffffffff9758bbf5>] free_msi_irqs+0x65/0x190 ... Call Trace: [<ffffffff9758cda4>] pci_disable_msi+0x34/0x40 [<ffffffff97583817>] cleanup_service_irqs+0x27/0x30 [<ffffffff97583e9a>] pcie_port_device_remove+0x2a/0x40 [<ffffffff97584250>] pcie_portdrv_remove+0x40/0x50 [<ffffffff97576d7b>] pci_device_remove+0x4b/0xc0 [<ffffffff9785ebe6>] __device_release_driver+0xb6/0x150 [<ffffffff9785eca5>] device_release_driver+0x25/0x40 [<ffffffff975702e4>] pci_stop_bus_device+0x74/0xa0 [<ffffffff975704ea>] pci_stop_and_remove_bus_device_locked+0x1a/0x30 [<ffffffff97578810>] remove_store+0x50/0x70 [<ffffffff9785a378>] dev_attr_store+0x18/0x30 [<ffffffff97260b64>] sysfs_kf_write+0x44/0x60 [<ffffffff9725feae>] kernfs_fop_write+0x10e/0x190 [<ffffffff971e13f8>] __vfs_write+0x28/0x110 [<ffffffff970b0fa4>] ? percpu_down_read+0x44/0x80 [<ffffffff971e53a7>] ? __sb_start_write+0xa7/0xe0 [<ffffffff971e53a7>] ? __sb_start_write+0xa7/0xe0 [<ffffffff971e1f04>] vfs_write+0xc4/0x180 [<ffffffff971e3089>] SyS_write+0x49/0xa0 [<ffffffff97001a46>] do_syscall_64+0xa6/0x1b0 [<ffffffff9819201e>] entry_SYSCALL64_slow_path+0x25/0x25 ... RIP [<ffffffff9758bbf5>] free_msi_irqs+0x65/0x190 RSP <ffff89ad3085bc48> ---[ end trace f4505e1dac5b95d3 ]--- Segmentation fault Restore pcie_pme_remove(). [bhelgaas: changelog] Fixes: d7def2040077 ("PCI/PME: Make explicitly non-modular") Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> CC: stable@vger.kernel.org # v4.9+
2016-12-12PCI/PME: Log PME IRQ when claiming Root PortBjorn Helgaas1-6/+6
We already log a "Signaling PME" whenever the PME service driver claims a Root Port. In fact, we also log the same message for every device in the hierarchy below the Root Port. Log the "Signaling PME" once (only for the Root Port, since we can trivially find out which devices are below the Root Port), and include the IRQ number in the message to help connect the dots with /proc/interrupts. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-12-12PCI/PME: Drop unused support for PMEs from Root Complex Event CollectorsBjorn Helgaas1-16/+1
Since we register pcie_pme_driver only for PCI_EXP_TYPE_ROOT_PORT, the PME driver never claims Root Complex Event Collectors. Remove unused code related to Root Complex Event Collectors. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-08-24PCI/PME: Make explicitly non-modularPaul Gortmaker1-15/+1
This code is not being built as a module by anyone: config PCIE_PME def_bool y depends on PCIEPORTBUS && PM Remove traces of modularity so that when reading the driver there is no doubt it is builtin-only. Also delete the .remove function, since that doesn't seem to have a sensible use case. With "normal" endpoint drivers, we have in the past set the suppress_bind_attrs bit to make it clear that the use of ".remove" in a builtin driver was deleted, but here for PCI, it seems overkill to jump through the pcie_port_service_driver and into the struct device_driver in order to finally try and do something similar with the bind setting. Note that for non-modular code, module_init() translates to device_initcall(). Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-02-05PCI/PME: Restructure pcie_pme_suspend() to prevent compiler warningBjorn Helgaas1-3/+6
Previously we had this: if (wakeup) ret = enable_irq_wake(...); if (!wakeup || ret) ... "ret" is only evaluated when "wakeup" is true, and it is always initialized in that case, but gcc isn't smart enough to figure that out and warns: drivers/pci/pcie/pme.c:414:14: warning: 'ret' may be used uninitialized in this function [-Wmaybe-uninitialized] Restructure the code slightly to make it easier for gcc (and maybe for humans as well). Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com
2016-02-05PCI/PME: Remove redundant port lookupBjorn Helgaas1-2/+0
We've already looked up srv->port a few lines earlier, and there's no need to do it again. Remove the redundant lookup. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com
2014-10-23PCI / PM: handle failure to enable wakeup on PCIe PMELucas Stach1-2/+4
If the irqchip handling the PCIe PME interrupt is not able to enable interrupt wakeup we should properly reflect this in the PME suspend status. This fixes a kernel warning on resume, where it would try to disable the irq wakeup that failed to be activated while suspending, for example: WARNING: CPU: 0 PID: 609 at kernel/irq/manage.c:536 irq_set_irq_wake+0xc0/0xf8() Unbalanced IRQ 384 wake disable Fixes: 76cde7e49590 (PCI / PM: Make PCIe PME interrupts wake up from suspend-to-idle) Reported-and-tested-by: Richard Zhu <richard.zhu@freescale.com> Signed-off-by: Lucas Stach <l.stach@pengutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-09-01PCI / PM: Make PCIe PME interrupts wake up from suspend-to-idleRafael J. Wysocki1-10/+51
To make PCIe PME interrupts wake up the system from suspend to idle, make the PME driver use enable_irq_wake() on the IRQ during system suspend (if there are any wakeup devices below the given PCIe port) without disabling PME interrupts. This way, an interrupt will still trigger if a wakeup event happens and the system will be woken up (or system suspend in progress will be aborted) by means of the new mechanics introduced previously. This change allows Wake-on-LAN to be used for wakeup from suspend-to-idle on my MSI Wind tesbed netbook. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-10PCI: Merge multi-line quoted stringsRyan Desfosses1-2/+1
Merge quoted strings that are broken across lines into a single entity. The compiler merges them anyway, but checkpatch complains about it, and merging them makes it easier to grep for strings. No functional change. [bhelgaas: changelog, do the same for everything under drivers/pci] Signed-off-by: Ryan Desfosses <ryan@desfo.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2013-11-14PCI: Fix whitespace, capitalization, and spelling errorsBjorn Helgaas1-2/+2
Fix whitespace, capitalization, and spelling errors. No functional change. I know "busses" is not an error, but "buses" was more common, so I used it consistently. Signed-off-by: Marta Rybczynska <rybczynska@gmail.com> (pci_reset_bridge_secondary_bus()) Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-06-10PCI: Fix comment typo for pcie_pme_remove()Yijing Wang1-1/+1
Fix trivial comment typo for pcie_pme_remove(). Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2013-04-15PCI: Remove unnecessary dependencies between PME and ACPIBjorn Helgaas1-2/+0
PCIe PME doesn't depend on ACPI, so remove the #includes and Kconfig dependency. Based-on-patch-by: Andrew Murray <Andrew.Murray@arm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-08-23PCI/PME: Use PCI Express Capability accessorsJiang Liu1-17/+6
Use PCI Express Capability access functions to simplify PCIe PME. Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-08-23PCI: Introduce pci_pcie_type(dev) to replace pci_dev->pcie_typeYijing Wang1-3/+3
Introduce an inline function pci_pcie_type(dev) to extract PCIe device type from pci_dev->pcie_flags_reg field, and prepare for removing pci_dev->pcie_type. Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2011-10-14PCI / PM: Extend PME polling to all PCI devicesRafael J. Wysocki1-0/+9
The land of PCI power management is a land of sorrow and ugliness, especially in the area of signaling events by devices. There are devices that set their PME Status bits, but don't really bother to send a PME message or assert PME#. There are hardware vendors who don't connect PME# lines to the system core logic (they know who they are). There are PCI Express Root Ports that don't bother to trigger interrupts when they receive PME messages from the devices below. There are ACPI BIOSes that forget to provide _PRW methods for devices capable of signaling wakeup. Finally, there are BIOSes that do provide _PRW methods for such devices, but then don't bother to call Notify() for those devices from the corresponding _Lxx/_Exx GPE-handling methods. In all of these cases the kernel doesn't have a chance to receive a proper notification that it should wake up a device, so devices stay in low-power states forever. Worse yet, in some cases they continuously send PME Messages that are silently ignored, because the kernel simply doesn't know that it should clear the device's PME Status bit. This problem was first observed for "parallel" (non-Express) PCI devices on add-on cards and Matthew Garrett addressed it by adding code that polls PME Status bits of such devices, if they are enabled to signal PME, to the kernel. Recently, however, it has turned out that PCI Express devices are also affected by this issue and that it is not limited to add-on devices, so it seems necessary to extend the PME polling to all PCI devices, including PCI Express and planar ones. Still, it would be wasteful to poll the PME Status bits of devices that are known to receive proper PME notifications, so make the kernel (1) poll the PME Status bits of all PCI and PCIe devices enabled to signal PME and (2) disable the PME Status polling for devices for which correct PME notifications are received. Tested-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-01-14PCI/PM: Report wakeup events before resuming devicesRafael J. Wysocki1-2/+2
Make wakeup events be reported by the PCI subsystem before attempting to resume devices or queuing up runtime resume requests for them, because wakeup events should be reported as soon as they have been detected. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-12-23PCI/PCIe: Clear Root PME Status bits early during system resumeRafael J. Wysocki1-23/+4
I noticed that PCI Express PMEs don't work on my Toshiba Portege R500 after the system has been woken up from a sleep state by a PME (through Wake-on-LAN). After some investigation it turned out that the BIOS didn't clear the Root PME Status bit in the root port that received the wakeup PME and since the Requester ID was also set in the port's Root Status register, any subsequent PMEs didn't trigger interrupts. This problem can be avoided by clearing the Root PME Status bits in all PCI Express root ports during early resume. For this purpose, add an early resume routine to the PCIe port driver and make this driver be always registered, even if pci_ports_disable is set (in which case the driver's only function is to provide the early resume callback). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-08-24PCI: PCIe: Move PCIe PME code to the pcie directoryRafael J. Wysocki1-0/+462
The PCIe PME code only consists of one file, so it doesn't need to occupy its own directory. Move it to drivers/pci/pcie/pme.c and remove the contents of drivers/pci/pcie/pme . Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>