kernel.git/drivers/pci/hotplug/pciehp_core.c, branch linux-5.9.y

PCI: Fix kerneldoc warnings

2020-08-05T23:23:14Z

Fix kerneldoc warnings, e.g., $ make W=1 drivers/pci/ drivers/pci/ats.c:196: warning: Function parameter or member 'pdev' not described in 'pci_enable_pri' drivers/pci/ats.c:196: warning: Function parameter or member 'reqs' not described in 'pci_enable_pri' ... Link: https://lore.kernel.org/r/20200729201224.26799-2-krzk@kernel.org Link: https://lore.kernel.org/r/20200729201224.26799-3-krzk@kernel.org Link: https://lore.kernel.org/r/20200729201224.26799-4-krzk@kernel.org Link: https://lore.kernel.org/r/20200729201224.26799-5-krzk@kernel.org Link: https://lore.kernel.org/r/20200729201224.26799-6-krzk@kernel.org Link: https://lore.kernel.org/r/20200729201224.26799-7-krzk@kernel.org Signed-off-by: Krzysztof Kozlowski Signed-off-by: Bjorn Helgaas

PM: sleep: core: Rename dev_pm_smart_suspend_and_suspended()

2020-04-24T19:32:41Z

Because all callers of dev_pm_smart_suspend_and_suspended use it only for checking whether or not to skip driver suspend callbacks for a device, rename it to dev_pm_skip_suspend() in analogy with dev_pm_skip_resume(). No functional impact. Suggested-by: Alan Stern Signed-off-by: Rafael J. Wysocki Acked-by: Alan Stern Acked-by: Bjorn Helgaas

PCI: pciehp: Prevent deadlock on disconnect

2019-11-12T23:17:42Z

This addresses deadlocks in these common cases in hierarchies containing two switches: - All involved ports are runtime suspended and they are unplugged. This can happen easily if the drivers involved automatically enable runtime PM (xHCI for example does that). - System is suspended (e.g., closing the lid on a laptop) with a dock + something else connected, and the dock is unplugged while suspended. These cases lead to the following deadlock: INFO: task irq/126-pciehp:198 blocked for more than 120 seconds. irq/126-pciehp D 0 198 2 0x80000000 Call Trace: schedule+0x2c/0x80 schedule_timeout+0x246/0x350 wait_for_completion+0xb7/0x140 kthread_stop+0x49/0x110 free_irq+0x32/0x70 pcie_shutdown_notification+0x2f/0x50 pciehp_remove+0x27/0x50 pcie_port_remove_service+0x36/0x50 device_release_driver+0x12/0x20 bus_remove_device+0xec/0x160 device_del+0x13b/0x350 device_unregister+0x1a/0x60 remove_iter+0x1e/0x30 device_for_each_child+0x56/0x90 pcie_port_device_remove+0x22/0x40 pcie_portdrv_remove+0x20/0x60 pci_device_remove+0x3e/0xc0 device_release_driver_internal+0x18c/0x250 device_release_driver+0x12/0x20 pci_stop_bus_device+0x6f/0x90 pci_stop_bus_device+0x31/0x90 pci_stop_and_remove_bus_device+0x12/0x20 pciehp_unconfigure_device+0x88/0x140 pciehp_disable_slot+0x6a/0x110 pciehp_handle_presence_or_link_change+0x263/0x400 pciehp_ist+0x1c9/0x1d0 irq_thread_fn+0x24/0x60 irq_thread+0xeb/0x190 kthread+0x120/0x140 INFO: task irq/190-pciehp:2288 blocked for more than 120 seconds. irq/190-pciehp D 0 2288 2 0x80000000 Call Trace: __schedule+0x2a2/0x880 schedule+0x2c/0x80 schedule_preempt_disabled+0xe/0x10 mutex_lock+0x2c/0x30 pci_lock_rescan_remove+0x15/0x20 pciehp_unconfigure_device+0x4d/0x140 pciehp_disable_slot+0x6a/0x110 pciehp_handle_presence_or_link_change+0x263/0x400 pciehp_ist+0x1c9/0x1d0 irq_thread_fn+0x24/0x60 irq_thread+0xeb/0x190 kthread+0x120/0x140 What happens here is that the whole hierarchy is runtime resumed and the parent PCIe downstream port, which got the hot-remove event, starts removing devices below it, taking pci_lock_rescan_remove() lock. When the child PCIe port is runtime resumed it calls pciehp_check_presence() which ends up calling pciehp_card_present() and pciehp_check_link_active(). Both of these use pcie_capability_read_word(), which notices that the underlying device is already gone and returns PCIBIOS_DEVICE_NOT_FOUND with the capability value set to 0. When pciehp gets this value it thinks that its child device is also hot-removed and schedules its IRQ thread to handle the event. The deadlock happens when the child's IRQ thread runs and tries to acquire pci_lock_rescan_remove() which is already taken by the parent and the parent waits for the child's IRQ thread to finish. Prevent this from happening by checking the return value of pcie_capability_read_word() and if it is PCIBIOS_DEVICE_NOT_FOUND stop performing any hot-removal activities. [bhelgaas: add common scenarios to commit log] Link: https://lore.kernel.org/r/20191029170022.57528-2-mika.westerberg@linux.intel.com Tested-by: Kai-Heng Feng Signed-off-by: Mika Westerberg Signed-off-by: Bjorn Helgaas

PCI: pciehp: Do not disable interrupt twice on suspend

2019-11-12T22:27:33Z

We try to keep PCIe hotplug ports runtime suspended when entering system suspend. Because the PCIe portdrv sets the DPM_FLAG_NEVER_SKIP flag, the PM core always calls system suspend/resume hooks even if the device is left runtime suspended. Since PCIe hotplug driver re-used the same function for both runtime suspend and system suspend, it ended up disabling hotplug interrupt twice and the second time following was printed: pciehp 0000:03:01.0:pcie204: pcie_do_write_cmd: no response from device Prevent this from happening by checking whether the device is already runtime suspended when the system suspend hook is called. Fixes: 9c62f0bfb832 ("PCI: pciehp: Implement runtime PM callbacks") Link: https://lore.kernel.org/r/20191029170022.57528-1-mika.westerberg@linux.intel.com Reported-by: Kai-Heng Feng Tested-by: Kai-Heng Feng Signed-off-by: Mika Westerberg Signed-off-by: Bjorn Helgaas Reviewed-by: Rafael J. Wysocki

PCI: pciehp: Remove pciehp_set_attention_status()

2019-09-05T20:44:08Z

Remove pciehp_set_attention_status() and use pciehp_set_indicators() instead, since the code is mostly the same. Link: https://lore.kernel.org/r/20190903111021.1559-4-efremov@linux.com Signed-off-by: Denis Efremov Signed-off-by: Bjorn Helgaas Reviewed-by: Kuppuswamy Sathyanarayanan

PCI: pciehp: Remove pointless PCIE_MODULE_NAME definition

2019-05-09T21:45:21Z

PCIE_MODULE_NAME is only used once and offers no benefit, so remove it. Link: https://lore.kernel.org/lkml/20190509141456.223614-10-helgaas@kernel.org Signed-off-by: Bjorn Helgaas Reviewed-by: Keith Busch Reviewed-by: Andy Shevchenko

PCI: pciehp: Remove unused dbg/err/info/warn() wrappers

2019-05-09T21:45:20Z

Replace the last uses of dbg() with the equivalent pr_debug(), then remove unused dbg(), err(), info(), and warn() wrappers. Link: https://lore.kernel.org/lkml/20190509141456.223614-9-helgaas@kernel.org Signed-off-by: Frederick Lawler Signed-off-by: Bjorn Helgaas Reviewed-by: Keith Busch Reviewed-by: Andy Shevchenko

PCI: pciehp: Log messages with pci_dev, not pcie_device

2019-05-09T21:45:20Z

Log messages with pci_dev, not pcie_device. Factor out common message prefixes with dev_fmt(). Example output change: - pciehp 0000:00:06.0:pcie004: Slot(0) Powering on due to button press + pcieport 0000:00:06.0: pciehp: Slot(0) Powering on due to button press Link: https://lore.kernel.org/lkml/20190509141456.223614-8-helgaas@kernel.org Signed-off-by: Frederick Lawler Signed-off-by: Bjorn Helgaas Reviewed-by: Keith Busch Reviewed-by: Andy Shevchenko

PCI: pciehp: Replace pciehp_debug module param with dyndbg

2019-05-09T21:45:20Z

Previously pciehp debug messages were enabled by the pciehp_debug module parameter, e.g., by booting with this kernel command line option: pciehp.pciehp_debug=1 Convert this mechanism to use the generic dynamic debug (dyndbg) feature. After this commit, pciehp debug messages are enabled by building the kernel with CONFIG_DYNAMIC_DEBUG=y and booting with this command line option: dyndbg="file pciehp* +p" The dyndbg facility is much more flexible: messages can be enabled at boot- or run-time based on the file name, function name, line number, message test, etc. See Documentation/admin-guide/dynamic-debug-howto.rst for more details. Link: https://lore.kernel.org/lkml/20190509141456.223614-7-helgaas@kernel.org Signed-off-by: Frederick Lawler [bhelgaas: commit log, comment, remove pciehp_debug parameter] Signed-off-by: Bjorn Helgaas Reviewed-by: Keith Busch Reviewed-by: Andy Shevchenko

PCI: pciehp: Implement runtime PM callbacks

2018-10-02T21:04:40Z

Basically we need to do the same thing when runtime suspending than with system sleep so re-use those operations here. This makes sure hotplug interrupt does not trigger immediately when the link goes down. Signed-off-by: Mika Westerberg Signed-off-by: Bjorn Helgaas Reviewed-by: Rafael J. Wysocki