linux/drivers/pci
Lukas Wunner 11e87702be PCI: pciehp: Differentiate between surprise and safe removal
When removing PCI devices below a hotplug bridge, pciehp marks them as
disconnected if the card is no longer present in the slot or it quiesces
them if the card is still present (by disabling INTx interrupts, bus
mastering and SERR# reporting).

To detect whether the card is still present, pciehp checks the Presence
Detect State bit in the Slot Status register.  The problem with this
approach is that even if the card is present, the link to it may be
down, and it that case it would be better to mark the devices as
disconnected instead of trying to quiesce them.  Moreover, if the card
in the slot was quickly replaced by another one, the Presence Detect
State bit would be set, yet trying to quiesce the new card's devices
would be wrong and the correct thing to do is to mark the previous
card's devices as disconnected.

Instead of looking at the Presence Detect State bit, it is better to
differentiate whether the card was surprise removed versus safely
removed (via sysfs or an Attention Button press).  On surprise removal,
the devices should be marked as disconnected, whereas on safe removal it
is correct to quiesce the devices.

The knowledge whether a surprise removal or a safe removal is at hand
does exist further up in the call stack:  A surprise removal is
initiated by pciehp_handle_presence_or_link_change(), a safe removal by
pciehp_handle_disable_request().

Pass that information down to pciehp_unconfigure_device() and use it in
lieu of the Presence Detect State bit.  While there, add kernel-doc to
pciehp_unconfigure_device() and pciehp_configure_device().

Tested-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Keith Busch <keith.busch@intel.com>
2018-09-17 16:34:35 -05:00
..
controller pci-v4.19-changes 2018-08-16 09:21:54 -07:00
endpoint Merge branch 'remotes/lorenzo/pci/dwc' 2018-08-15 14:59:11 -05:00
hotplug PCI: pciehp: Differentiate between surprise and safe removal 2018-09-17 16:34:35 -05:00
pcie PCI: Simplify disconnected marking 2018-09-17 16:34:35 -05:00
switch switchtec: Fix Spectre v1 vulnerability 2018-09-11 08:47:40 -05:00
access.c Merge branch 'pci/vpd' 2018-04-04 13:28:40 -05:00
ats.c PCI: Enable PASID only if entire path supports End-End TLP prefixes 2018-06-30 14:10:03 -05:00
bus.c PCI: Fix is_added/is_busmaster race condition 2018-07-31 11:27:54 -05:00
ecam.c PCI: Add SPDX GPL-2.0 to replace GPL v2 boilerplate 2018-01-28 15:48:29 -06:00
host-bridge.c PCI: Tidy comments 2018-03-19 14:20:43 -05:00
iov.c Merge branch 'pci/virtualization' 2018-08-15 14:59:06 -05:00
irq.c PCI: Use IRQF_ONESHOT if pci_request_irq() called with no handler 2018-07-31 10:43:43 -05:00
Kconfig PCI: Collect all native drivers under drivers/pci/controller/ 2018-06-08 07:50:11 -05:00
Makefile PCI: Initialize endpoint library before controllers 2018-06-26 15:37:37 -05:00
mmap.c PCI: Tidy comments 2018-03-19 14:20:43 -05:00
msi.c PCI/MSI: Set IRQCHIP_ONESHOT_SAFE for PCI-MSI irqchips 2018-08-14 16:11:02 -05:00
of.c Merge branch 'pci/resource' 2018-08-15 14:59:01 -05:00
pci-acpi.c More power management updates for 4.19-rc1 2018-08-22 07:42:36 -07:00
pci-driver.c Merge branch 'pci/misc' 2018-08-15 14:58:54 -05:00
pci-label.c PCI: Tidy comments 2018-03-19 14:20:43 -05:00
pci-mid.c PCI: Add SPDX GPL-2.0 to replace GPL v2 boilerplate 2018-01-28 15:48:29 -06:00
pci-pf-stub.c PCI/IOV: Add pci-pf-stub driver for PFs that only enable VFs 2018-04-24 16:47:16 -05:00
pci-stub.c PCI: Tidy comments 2018-03-19 14:20:43 -05:00
pci-sysfs.c Merge branch 'pci/hotplug' 2018-08-15 14:58:52 -05:00
pci.c IB/hfi1,PCI: Allow bus reset while probing 2018-09-11 21:44:52 -05:00
pci.h Merge branch 'pci/virtualization' 2018-08-15 14:59:06 -05:00
probe.c PCI: Fix enabling of PASID on RC integrated endpoints 2018-09-11 21:46:49 -05:00
proc.c proc: introduce proc_create_seq{,_data} 2018-05-16 07:23:35 +02:00
quirks.c Revert "PCI: Add ACS quirk for Intel 300 series" 2018-09-11 08:47:38 -05:00
remove.c Merge branch 'pci/aspm' 2018-08-15 14:58:46 -05:00
rom.c PCI: Make pci_get_rom_size() static 2018-06-29 21:17:26 -05:00
search.c PCI: Tidy comments 2018-03-19 14:20:43 -05:00
setup-bus.c PCI: Move resource distribution for single bridge outside loop 2018-06-04 12:08:06 -05:00
setup-irq.c PCI: Tidy comments 2018-03-19 14:20:43 -05:00
setup-res.c PCI: Remove messages about reassigning resources 2018-04-11 08:46:50 -05:00
slot.c Merge branch 'pci/misc' 2018-04-04 13:27:45 -05:00
syscall.c PCI: Tidy comments 2018-03-19 14:20:43 -05:00
vc.c Merge branch 'pci/spdx' into next 2018-02-01 11:40:07 -06:00
vpd.c PCI/VPD: Check for VPD access completion before checking for timeout 2018-08-14 16:04:46 -05:00
xen-pcifront.c PCI: Tidy comments 2018-03-19 14:20:43 -05:00