linux-stable.git/drivers/pci, branch v3.17

Merge tag 'pci-v3.17-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

2014-09-24T16:46:29+00:00

Pull PCI fixes from Bjorn Helgaas:
 "Here are a few fixes that should be in v3.17.

   - Reverting "Don't scan random busses" covers up a CardBus regression
     having to do with allocating CardBus bus numbers.

   - Reverting "Make sure bus numbers stay within parents bounds" covers
     up an ACPI _CRS bug that makes us reconfigure a bridge, causing a
     broken device behind it to stop responding.

   - The pciehp timeout change fixes some code we added in v3.17.
     Without the fix, we can send a new hotplug command too early,
     before the timeout has expired.

  I hope for better fixes for the reverts, but those will have to come
  after v3.17"

* tag 'pci-v3.17-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI: pciehp: Fix pcie_wait_cmd() timeout
  Revert "PCI: Make sure bus number resources stay within their parents bounds"
  Revert "PCI: Don't scan random busses in pci_scan_bridge()"

PCI: pciehp: Fix pcie_wait_cmd() timeout

2014-09-23T02:05:45+00:00

pcie_poll_cmd() take msecs instead of jiffies, so convert timeout to msecs.

Fixes: 40b960831cfa ("PCI: pciehp: Compute timeout from hotplug command start time")
Signed-off-by: Yinghai Lu 
Signed-off-by: Bjorn Helgaas

Merge tag 'pci-v3.17-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

2014-09-19T17:50:30+00:00

Pull PCI fixes from Bjorn Helgaas:
 "These fix:

   - Boot video device detection on dual-GPU Apple systems
   - Hotplug fiascos on VGA switcheroo with radeon & nouveau drivers
   - Boot hang on Freescale i.MX6 systems
   - Excessive "no hotplug settings from platform" warnings

  In particular:

  Enumeration
    - Don't default exclusively to first video device (Bruno Prémont)

  PCI device hotplug
    - Remove "no hotplug settings from platform" warning (Bjorn Helgaas)
    - Add pci_ignore_hotplug() for VGA switcheroo (Bjorn Helgaas)

  Freescale i.MX6
    - Put LTSSM in "Detect" state before disabling (Lucas Stach)"

* tag 'pci-v3.17-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  vgaarb: Drop obsolete #ifndef
  vgaarb: Don't default exclusively to first video device with mem+io
  ACPIPHP / radeon / nouveau: Remove acpi_bus_no_hotplug()
  PCI: Remove "no hotplug settings from platform" warning
  PCI: Add pci_ignore_hotplug() to ignore hotplug events for a device
  PCI: imx6: Put LTSSM in "Detect" state before disabling it
  MAINTAINERS: Add Lucas Stach as co-maintainer for i.MX6 PCI driver

Revert "PCI: Make sure bus number resources stay within their parents bounds"

2014-09-19T17:08:40+00:00

This reverts commit 1820ffdccb9b ("PCI: Make sure bus number resources stay
within their parents bounds") because it breaks some systems with LSI Logic
FC949ES Fibre Channel Adapters, apparently by exposing a defect in those
adapters.

Dirk tested a Tyan VX50 (B4985) with this device that worked like this
prior to 1820ffdccb9b:

    bus: [bus 00-7f] on node 0 link 1
    ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-07])
    pci 0000:00:0e.0: PCI bridge to [bus 0a]
    pci_bus 0000:0a: busn_res: can not insert [bus 0a] under [bus 00-07] (conflicts with (null) [bus 00-07])
    pci 0000:0a:00.0: [1000:0646] type 00 class 0x0c0400 (FC adapter)

Note that the root bridge [bus 00-07] aperture is wrong; this is a BIOS
defect in the PCI0 _CRS method.  But prior to 1820ffdccb9b, we didn't
enforce that aperture, and the FC adapter worked fine at 0a:00.0.

After 1820ffdccb9b, we notice that 00:0e.0's aperture is not contained in
the root bridge's aperture, so we reconfigure it so it *is* contained:

    pci 0000:00:0e.0: bridge configuration invalid ([bus 0a-0a]), reconfiguring
    pci 0000:00:0e.0: PCI bridge to [bus 06-07]

This effectively moves the FC device from 0a:00.0 to 07:00.0, which should
be legal.  But when we enumerate bus 06, the FC device doesn't respond, so
we don't find anything.  This is probably a defect in the FC device.

Possible fixes (due to Yinghai):

    1) Add a quirk to fix the _CRS information based on what amd_bus.c read
       from the hardware

    2) Reset the FC device after we change its bus number

    3) Revert 1820ffdccb9b

Fix 1 would be relatively easy, but it does sweep the LSI FC issue under
the rug.  We might want to reconfigure bus numbers in the future for some
other reason, e.g., hotplug, and then we could trip over this again.

For that reason, I like fix 2, but we don't know whether it actually works,
and we don't have a patch for it yet.

This revert is fix 3, which also sweeps the LSI FC issue under the rug.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=84281
Reported-by: Dirk Gouders 
Tested-by: Dirk Gouders 
Signed-off-by: Bjorn Helgaas 
CC: stable@vger.kernel.org	# v3.15+
CC: Yinghai Lu

Revert "PCI: Don't scan random busses in pci_scan_bridge()"

2014-09-19T16:56:06+00:00

This reverts commit fc1b253141b3 ("PCI: Don't scan random busses in
pci_scan_bridge()") because it breaks CardBus on some machines.

David tested a Dell Latitude D505 that worked like this prior to
fc1b253141b3:

    pci 0000:00:1e.0: PCI bridge to [bus 01]
    pci 0000:01:01.0: CardBus bridge to [bus 02-05]

Note that the 01:01.0 CardBus bridge has a bus number aperture of
[bus 02-05], but those buses are all outside the 00:1e.0 PCI bridge bus
number aperture, so accesses to buses 02-05 never reach CardBus.  This is
later patched up by yenta_fixup_parent_bridge(), which changes the
subordinate bus number of the 00:1e.0 PCI bridge:

    pci_bus 0000:01: Raising subordinate bus# of parent bus (#01) from #01 to #05

With fc1b253141b3, pci_scan_bridge() fails immediately when it notices that
we can't allocate a valid secondary bus number for the CardBus bridge, and
CardBus doesn't work at all:

    pci 0000:01:01.0: can't allocate child bus 01 from [bus 01]

I'd prefer to fix this by integrating the yenta_fixup_parent_bridge() logic
into pci_scan_bridge() so we fix the bus number apertures up front.  But
I don't think we can do that before v3.17, so I'm going to revert this to
avoid the problem while we're working on the long-term fix.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=83441
Link: http://lkml.kernel.org/r/1409303414-5196-1-git-send-email-david.henningsson@canonical.com
Reported-by: David Henningsson 
Tested-by: David Henningsson 
Signed-off-by: Bjorn Helgaas 
CC: stable@vger.kernel.org	# v3.15+

Merge branch 'pci/vga'; commit '6a73336bde29' into for-linus

2014-09-19T05:05:06+00:00

* pci/vga:
  vgaarb: Drop obsolete #ifndef
  vgaarb: Don't default exclusively to first video device with mem+io

* commit '6a73336bde29':
  PCI: Remove "no hotplug settings from platform" warning

Merge branch 'pci/hotplug-vga' into for-linus

2014-09-15T19:18:36+00:00

* pci/hotplug-vga:
  ACPIPHP / radeon / nouveau: Remove acpi_bus_no_hotplug()
  PCI: Add pci_ignore_hotplug() to ignore hotplug events for a device

PCI: Remove "no hotplug settings from platform" warning

2014-09-12T14:50:10+00:00

We print way too many messages like this:

    pci 0000:00:00.0: no hotplug settings from platform
    pci 0000:00:00.0: using default PCI settings

This usually happens when the platform doesn't supply an ACPI _HPP method,
but the method is optional, so there's no point in warning about it.

Not only are the messages useless, but we call pci_configure_slot() far too
many times, so they're repeated many times.  I'll fix the overuse of
pci_configure_slot() too, but that will wait until the next merge window.

For now, just remove both log messages.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=84391
Signed-off-by: Bjorn Helgaas 
Acked-by: Yinghai Lu

PCI: Add pci_ignore_hotplug() to ignore hotplug events for a device

2014-09-10T19:45:01+00:00

Powering off a hot-pluggable device, e.g., with pci_set_power_state(D3cold),
normally generates a hot-remove event that unbinds the driver.

Some drivers expect to remain bound to a device even while they power it
off and back on again. This can be dangerous, because if the device is
removed or replaced while it is powered off, the driver doesn't know that
anything changed. But some drivers accept that risk.

Add pci_ignore_hotplug() for use by drivers that know their device cannot
be removed. Using pci_ignore_hotplug() tells the PCI core that hot-plug
events for the device should be ignored.

The radeon and nouveau drivers use this to switch between a low-power,
integrated GPU and a higher-power, higher-performance discrete GPU. They
power off the unused GPU, but they want to remain bound to it.

This is a reimplementation of f244d8b623da ("ACPIPHP / radeon / nouveau:
Fix VGA switcheroo problem related to hotplug") but extends it to work with
both acpiphp and pciehp.

This fixes a problem where systems with dual GPUs using the radeon drivers
become unusable, freezing every few seconds (see bugzillas below). The
resume of the radeon device may also fail, e.g.,

This fixes problems on dual GPU systems where the radeon driver becomes
unusable because of problems while suspending the device, as in bug 79701:

[drm] radeon: finishing device.
radeon 0000:01:00.0: Userspace still has active objects !
radeon 0000:01:00.0: ffff8800cb4ec288 ffff8800cb4ec000 16384 4294967297 force free
...
WARNING: CPU: 0 PID: 67 at /home/apw/COD/linux/drivers/gpu/drm/radeon/radeon_gart.c:234 radeon_gart_unbind+0xd2/0xe0 [radeon]()
trying to unbind memory from uninitialized GART !

or while resuming it, as in bug 77261:

radeon 0000:01:00.0: ring 0 stalled for more than 10158msec
radeon 0000:01:00.0: GPU lockup ...
radeon 0000:01:00.0: GPU pci config reset
pciehp 0000:00:01.0:pcie04: Card not present on Slot(1-1)
radeon 0000:01:00.0: GPU reset succeeded, trying to resume
*ERROR* radeon: dpm resume failed
radeon 0000:01:00.0: Wait for MC idle timedout !

Link: https://bugzilla.kernel.org/show_bug.cgi?id=77261
Link: https://bugzilla.kernel.org/show_bug.cgi?id=79701
Reported-by: Shawn Starr
Reported-by: Jose P.
Signed-off-by: Bjorn Helgaas
Acked-by: Alex Deucher
Acked-by: Rajat Jain
Acked-by: Rafael J. Wysocki
Acked-by: Dave Airlie
CC: stable@vger.kernel.org # v3.15+

PCI: imx6: Put LTSSM in "Detect" state before disabling it

2014-09-04T13:32:21+00:00

This fixes a boot hang observed when the bootloader already enabled the
PCIe link for its own use.  The fundamental problem is that Freescale
forgot to wire up the core reset, so software doesn't have a sane way to
get the core into a defined state.

According to the DW PCIe core reference manual, configuration of the core
may only happen when the LTSSM is disabled, so this is one of the first
things we need to do.  Apparently this isn't safe to do when the LTSSM is in
any state other than "detect" as we observe an instant machine hang when
trying to do so while the link is already up.

As a workaround, force LTSSM into detect state right before hitting the
disable switch.  There is still a race window because the LTSSM may
transition out of "detect" before we can disable it, but it's the best
we can do for now.

[bhelgaas: mention race window]
Link: http://lkml.kernel.org/r/1406830565-23450-3-git-send-email-l.stach@pengutronix.de
Reported-by: Fabio Estevam 
Signed-off-by: Lucas Stach 
Signed-off-by: Bjorn Helgaas 
Acked-by: Tim Harvey