linux-stable.git/drivers/pci, branch v4.20.2 Linux kernel stable tree PCI / PM: Allow runtime PM without callback functions 2019-01-13T08:24:06+00:00 Jarkko Nikula jarkko.nikula@linux.intel.com 2018-10-23T11:45:52+00:00 39e1be324c2f9048b013aaa190acf91b3f23b1a8 commit c5eb1190074cfb14c5d9cac692f1912eecf1a5e4 upstream. a9c8088c7988 ("i2c: i801: Don't restore config registers on runtime PM") nullified the runtime PM suspend/resume callback pointers while keeping the runtime PM enabled. This caused the SMBus PCI device to stay in D0 with /sys/devices/.../power/runtime_status showing "error" when the runtime PM framework attempted to autosuspend the device. This is due to PCI bus runtime PM, which checks for driver runtime PM callbacks and returns -ENOSYS if they are not set. Since i2c-i801.c doesn't need to do anything device-specific for runtime PM, Jean Delvare proposed this be fixed in the PCI core rather than adding dummy runtime PM callback functions in the PCI drivers. Change pci_pm_runtime_suspend()/pci_pm_runtime_resume() so they allow changing the PCI device power state during runtime PM transitions even if the driver supplies no runtime PM callbacks. This fixes the runtime PM regression on i2c-i801.c. It is not obvious why the code previously required the runtime PM callbacks. The test has been there since the code was introduced by 6cbf82148ff2 ("PCI PM: Run-time callbacks for PCI bus type"). On the other hand, a similar change was done to generic runtime PM callbacks in 05aa55dddb9e ("PM / Runtime: Lenient generic runtime pm callbacks"). Fixes: a9c8088c7988 ("i2c: i801: Don't restore config registers on runtime PM") Reported-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Jean Delvare <jdelvare@suse.de> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: stable@vger.kernel.org # v4.18+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit c5eb1190074cfb14c5d9cac692f1912eecf1a5e4 upstream.

a9c8088c7988 ("i2c: i801: Don't restore config registers on runtime PM")
nullified the runtime PM suspend/resume callback pointers while keeping the
runtime PM enabled.

This caused the SMBus PCI device to stay in D0 with
/sys/devices/.../power/runtime_status showing "error" when the runtime PM
framework attempted to autosuspend the device.  This is due to PCI bus
runtime PM, which checks for driver runtime PM callbacks and returns
-ENOSYS if they are not set.

Since i2c-i801.c doesn't need to do anything device-specific for runtime
PM, Jean Delvare proposed this be fixed in the PCI core rather than adding
dummy runtime PM callback functions in the PCI drivers.

Change pci_pm_runtime_suspend()/pci_pm_runtime_resume() so they allow
changing the PCI device power state during runtime PM transitions even if
the driver supplies no runtime PM callbacks.

This fixes the runtime PM regression on i2c-i801.c.

It is not obvious why the code previously required the runtime PM
callbacks.  The test has been there since the code was introduced by
6cbf82148ff2 ("PCI PM: Run-time callbacks for PCI bus type").

On the other hand, a similar change was done to generic runtime PM
callbacks in 05aa55dddb9e ("PM / Runtime: Lenient generic runtime pm
callbacks").

Fixes: a9c8088c7988 ("i2c: i801: Don't restore config registers on runtime PM")
Reported-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: stable@vger.kernel.org	# v4.18+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mm, hmm: mark hmm_devmem_{add, add_resource} EXPORT_SYMBOL_GPL 2019-01-13T08:24:04+00:00 Dan Williams dan.j.williams@intel.com 2018-12-28T08:35:15+00:00 8992f97a03be42cb89ee7238da56cdd8f49d4bbb commit 02917e9f8676207a4c577d4d94eae12bf348e9d7 upstream. At Maintainer Summit, Greg brought up a topic I proposed around EXPORT_SYMBOL_GPL usage. The motivation was considerations for when EXPORT_SYMBOL_GPL is warranted and the criteria for taking the exceptional step of reclassifying an existing export. Specifically, I wanted to make the case that although the line is fuzzy and hard to specify in abstract terms, it is nonetheless clear that devm_memremap_pages() and HMM (Heterogeneous Memory Management) have crossed it. The devm_memremap_pages() facility should have been EXPORT_SYMBOL_GPL from the beginning, and HMM as a derivative of that functionality should have naturally picked up that designation as well. Contrary to typical rules, the HMM infrastructure was merged upstream with zero in-tree consumers. There was a promise at the time that those users would be merged "soon", but it has been over a year with no drivers arriving. While the Nouveau driver is about to belatedly make good on that promise it is clear that HMM was targeted first and foremost at an out-of-tree consumer. HMM is derived from devm_memremap_pages(), a facility Christoph and I spearheaded to support persistent memory. It combines a device lifetime model with a dynamically created 'struct page' / memmap array for any physical address range. It enables coordination and control of the many code paths in the kernel built to interact with memory via 'struct page' objects. With HMM the integration goes even deeper by allowing device drivers to hook and manipulate page fault and page free events. One interpretation of when EXPORT_SYMBOL is suitable is when it is exporting stable and generic leaf functionality. The devm_memremap_pages() facility continues to see expanding use cases, peer-to-peer DMA being the most recent, with no clear end date when it will stop attracting reworks and semantic changes. It is not suitable to export devm_memremap_pages() as a stable 3rd party driver API due to the fact that it is still changing and manipulates core behavior. Moreover, it is not in the best interest of the long term development of the core memory management subsystem to permit any external driver to effectively define its own system-wide memory management policies with no encouragement to engage with upstream. I am also concerned that HMM was designed in a way to minimize further engagement with the core-MM. That, with these hooks in place, device-drivers are free to implement their own policies without much consideration for whether and how the core-MM could grow to meet that need. Going forward not only should HMM be EXPORT_SYMBOL_GPL, but the core-MM should be allowed the opportunity and stimulus to change and address these new use cases as first class functionality. Original changelog: hmm_devmem_add(), and hmm_devmem_add_resource() duplicated devm_memremap_pages() and are now simple now wrappers around the core facility to inject a dev_pagemap instance into the global pgmap_radix and hook page-idle events. The devm_memremap_pages() interface is base infrastructure for HMM. HMM has more and deeper ties into the kernel memory management implementation than base ZONE_DEVICE which is itself a EXPORT_SYMBOL_GPL facility. Originally, the HMM page structure creation routines copied the devm_memremap_pages() code and reused ZONE_DEVICE. A cleanup to unify the implementations was discussed during the initial review: http://lkml.iu.edu/hypermail/linux/kernel/1701.2/00812.html Recent work to extend devm_memremap_pages() for the peer-to-peer-DMA facility enabled this cleanup to move forward. In addition to the integration with devm_memremap_pages() HMM depends on other GPL-only symbols: mmu_notifier_unregister_no_release percpu_ref region_intersects __class_create It goes further to consume / indirectly expose functionality that is not exported to any other driver: alloc_pages_vma walk_page_range HMM is derived from devm_memremap_pages(), and extends deep core-kernel fundamentals. Similar to devm_memremap_pages(), mark its entry points EXPORT_SYMBOL_GPL(). [logang@deltatee.com: PCI/P2PDMA: match interface changes to devm_memremap_pages()] Link: http://lkml.kernel.org/r/20181130225911.2900-1-logang@deltatee.com Link: http://lkml.kernel.org/r/154275560565.76910.15919297436557795278.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: "Jérôme Glisse" <jglisse@redhat.com> Cc: Balbir Singh <bsingharora@gmail.com>, Cc: Michal Hocko <mhocko@suse.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 02917e9f8676207a4c577d4d94eae12bf348e9d7 upstream.

At Maintainer Summit, Greg brought up a topic I proposed around
EXPORT_SYMBOL_GPL usage.  The motivation was considerations for when
EXPORT_SYMBOL_GPL is warranted and the criteria for taking the exceptional
step of reclassifying an existing export.  Specifically, I wanted to make
the case that although the line is fuzzy and hard to specify in abstract
terms, it is nonetheless clear that devm_memremap_pages() and HMM
(Heterogeneous Memory Management) have crossed it.  The
devm_memremap_pages() facility should have been EXPORT_SYMBOL_GPL from the
beginning, and HMM as a derivative of that functionality should have
naturally picked up that designation as well.

Contrary to typical rules, the HMM infrastructure was merged upstream with
zero in-tree consumers.  There was a promise at the time that those users
would be merged "soon", but it has been over a year with no drivers
arriving.  While the Nouveau driver is about to belatedly make good on
that promise it is clear that HMM was targeted first and foremost at an
out-of-tree consumer.

HMM is derived from devm_memremap_pages(), a facility Christoph and I
spearheaded to support persistent memory.  It combines a device lifetime
model with a dynamically created 'struct page' / memmap array for any
physical address range.  It enables coordination and control of the many
code paths in the kernel built to interact with memory via 'struct page'
objects.  With HMM the integration goes even deeper by allowing device
drivers to hook and manipulate page fault and page free events.

One interpretation of when EXPORT_SYMBOL is suitable is when it is
exporting stable and generic leaf functionality.  The
devm_memremap_pages() facility continues to see expanding use cases,
peer-to-peer DMA being the most recent, with no clear end date when it
will stop attracting reworks and semantic changes.  It is not suitable to
export devm_memremap_pages() as a stable 3rd party driver API due to the
fact that it is still changing and manipulates core behavior.  Moreover,
it is not in the best interest of the long term development of the core
memory management subsystem to permit any external driver to effectively
define its own system-wide memory management policies with no
encouragement to engage with upstream.

I am also concerned that HMM was designed in a way to minimize further
engagement with the core-MM.  That, with these hooks in place,
device-drivers are free to implement their own policies without much
consideration for whether and how the core-MM could grow to meet that
need.  Going forward not only should HMM be EXPORT_SYMBOL_GPL, but the
core-MM should be allowed the opportunity and stimulus to change and
address these new use cases as first class functionality.

Original changelog:

hmm_devmem_add(), and hmm_devmem_add_resource() duplicated
devm_memremap_pages() and are now simple now wrappers around the core
facility to inject a dev_pagemap instance into the global pgmap_radix and
hook page-idle events.  The devm_memremap_pages() interface is base
infrastructure for HMM.  HMM has more and deeper ties into the kernel
memory management implementation than base ZONE_DEVICE which is itself a
EXPORT_SYMBOL_GPL facility.

Originally, the HMM page structure creation routines copied the
devm_memremap_pages() code and reused ZONE_DEVICE.  A cleanup to unify the
implementations was discussed during the initial review:
http://lkml.iu.edu/hypermail/linux/kernel/1701.2/00812.html Recent work to
extend devm_memremap_pages() for the peer-to-peer-DMA facility enabled
this cleanup to move forward.

In addition to the integration with devm_memremap_pages() HMM depends on
other GPL-only symbols:

    mmu_notifier_unregister_no_release
    percpu_ref
    region_intersects
    __class_create

It goes further to consume / indirectly expose functionality that is not
exported to any other driver:

    alloc_pages_vma
    walk_page_range

HMM is derived from devm_memremap_pages(), and extends deep core-kernel
fundamentals. Similar to devm_memremap_pages(), mark its entry points
EXPORT_SYMBOL_GPL().

[logang@deltatee.com: PCI/P2PDMA: match interface changes to devm_memremap_pages()]
  Link: http://lkml.kernel.org/r/20181130225911.2900-1-logang@deltatee.com
Link: http://lkml.kernel.org/r/154275560565.76910.15919297436557795278.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Balbir Singh <bsingharora@gmail.com>,
Cc: Michal Hocko <mhocko@suse.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
PCI/AER: Queue one GHES event, not several uninitialized ones 2018-12-14T17:29:37+00:00 Yanjiang Jin yanjiang.jin@hxt-semitech.com 2018-12-14T17:29:37+00:00 1063a5148ac9d1606e80886fa53ee57d45fb4589 ecae65e133f2 ("PCI/AER: Use kfifo_in_spinlocked() to insert locked elements") replaced kfifo_put() with kfifo_in_spinlocked(), but passed the *size* of the queue entry, where kfifo_in_spinlocked() expects the *number* of entries to be copied. We want to insert only one element into kfifo, not "sizeof(entry) = 16". Without this patch, we would get 15 uninitialized elements. Fixes: ecae65e133f2 ("PCI/AER: Use kfifo_in_spinlocked() to insert locked elements") Signed-off-by: Yanjiang Jin <yanjiang.jin@hxt-semitech.com> [bhelgaas: changelog] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Keith Busch <keith.busch@intel.com> 
ecae65e133f2 ("PCI/AER: Use kfifo_in_spinlocked() to insert locked
elements") replaced kfifo_put() with kfifo_in_spinlocked(), but passed the
*size* of the queue entry, where kfifo_in_spinlocked() expects the *number*
of entries to be copied.

We want to insert only one element into kfifo, not "sizeof(entry) = 16".
Without this patch, we would get 15 uninitialized elements.

Fixes: ecae65e133f2 ("PCI/AER: Use kfifo_in_spinlocked() to insert locked elements")
Signed-off-by: Yanjiang Jin <yanjiang.jin@hxt-semitech.com>
[bhelgaas: changelog]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
 Revert "PCI/ASPM: Do not initialize link state when aspm_disabled is set" 2018-12-04T00:05:17+00:00 Bjorn Helgaas bhelgaas@google.com 2018-12-04T00:05:17+00:00 b07b864ee4232b03125992a8f6a490b040adcb6a This reverts commit 17c91487364fb33797ed84022564ee7544ac4945. 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: 17c91487364f ("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> 
This reverts commit 17c91487364fb33797ed84022564ee7544ac4945.

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: 17c91487364f ("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>
 Merge remote-tracking branch 'lorenzo/pci/controller-fixes' into for-linus 2018-12-01T05:42:08+00:00 Bjorn Helgaas bhelgaas@google.com 2018-12-01T05:42:08+00:00 c74eadf881ad634c68880e2c1b504989d95993ee - Fix DesignWare endpoint MSI-X address calculation bug (Gustavo Pimentel) - Fix Layerscape outbound window disable usage (Hou Zhiqiang) - Fix imx6 link up detection (Trent Piepho) * lorenzo/pci/controller-fixes: PCI: dwc: Fix MSI-X EP framework address calculation bug PCI: layerscape: Fix wrong invocation of outbound window disable accessor PCI: imx6: Fix link training status detection in link up check 
  - Fix DesignWare endpoint MSI-X address calculation bug (Gustavo
    Pimentel)

  - Fix Layerscape outbound window disable usage (Hou Zhiqiang)

  - Fix imx6 link up detection (Trent Piepho)

* lorenzo/pci/controller-fixes:
  PCI: dwc: Fix MSI-X EP framework address calculation bug
  PCI: layerscape: Fix wrong invocation of outbound window disable accessor
  PCI: imx6: Fix link training status detection in link up check
PCI: Fix incorrect value returned from pcie_get_speed_cap() 2018-12-01T05:42:03+00:00 Mikulas Patocka mpatocka@redhat.com 2018-11-26T16:37:13+00:00 f1f90e254e46e0a14220e4090041f68256fbe297 The macros PCI_EXP_LNKCAP_SLS_*GB are values, not bit masks. We must mask the register and compare it against them. This fixes errors like this: amdgpu: [powerplay] failed to send message 261 ret is 0 when a PCIe-v3 card is plugged into a PCIe-v1 slot, because the slot is being incorrectly reported as PCIe-v3 capable. 6cf57be0f78e, which appeared in v4.17, added pcie_get_speed_cap() with the incorrect test of PCI_EXP_LNKCAP_SLS as a bitmask. 5d9a63304032, which appeared in v4.19, changed amdgpu to use pcie_get_speed_cap(), so the amdgpu bug reports below are regressions in v4.19. Fixes: 6cf57be0f78e ("PCI: Add pcie_get_speed_cap() to find max supported link speed") Fixes: 5d9a63304032 ("drm/amdgpu: use pcie functions for link width and speed") Link: https://bugs.freedesktop.org/show_bug.cgi?id=108704 Link: https://bugs.freedesktop.org/show_bug.cgi?id=108778 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> [bhelgaas: update comment, remove use of PCI_EXP_LNKCAP_SLS_8_0GB and PCI_EXP_LNKCAP_SLS_16_0GB since those should be covered by PCI_EXP_LNKCAP2, remove test of PCI_EXP_LNKCAP for zero, since that register is required] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org # v4.17+ 
The macros PCI_EXP_LNKCAP_SLS_*GB are values, not bit masks.  We must mask
the register and compare it against them.

This fixes errors like this:

  amdgpu: [powerplay] failed to send message 261 ret is 0

when a PCIe-v3 card is plugged into a PCIe-v1 slot, because the slot is
being incorrectly reported as PCIe-v3 capable.

6cf57be0f78e, which appeared in v4.17, added pcie_get_speed_cap() with the
incorrect test of PCI_EXP_LNKCAP_SLS as a bitmask.  5d9a63304032, which
appeared in v4.19, changed amdgpu to use pcie_get_speed_cap(), so the
amdgpu bug reports below are regressions in v4.19.

Fixes: 6cf57be0f78e ("PCI: Add pcie_get_speed_cap() to find max supported link speed")
Fixes: 5d9a63304032 ("drm/amdgpu: use pcie functions for link width and speed")
Link: https://bugs.freedesktop.org/show_bug.cgi?id=108704
Link: https://bugs.freedesktop.org/show_bug.cgi?id=108778
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
[bhelgaas: update comment, remove use of PCI_EXP_LNKCAP_SLS_8_0GB and
PCI_EXP_LNKCAP_SLS_16_0GB since those should be covered by PCI_EXP_LNKCAP2,
remove test of PCI_EXP_LNKCAP for zero, since that register is required]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org	# v4.17+
PCI: dwc: Fix MSI-X EP framework address calculation bug 2018-11-27T11:23:31+00:00 Gustavo Pimentel gustavo.pimentel@synopsys.com 2018-11-23T17:00:21+00:00 15cb127e3c8f6232096d5dba6a5b4046bc292d70 Fix an error caused by 3-bit right rotation on offset address calculation of MSI-X table in dw_pcie_ep_raise_msix_irq(). The initial testing code was setting by default the offset address of MSI-X table to zero, so that even with a 3-bit right rotation the computed result would still be zero and valid, therefore this bug went unnoticed. Fixes: beb4641a787d ("PCI: dwc: Add MSI-X callbacks handler") Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com> [lorenzo.pieralisi@arm.com: updated commit log] Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: stable@vger.kernel.org 
Fix an error caused by 3-bit right rotation on offset address
calculation of MSI-X table in dw_pcie_ep_raise_msix_irq().

The initial testing code was setting by default the offset address of
MSI-X table to zero, so that even with a 3-bit right rotation the
computed result would still be zero and valid, therefore this bug went
unnoticed.

Fixes: beb4641a787d ("PCI: dwc: Add MSI-X callbacks handler")
Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
[lorenzo.pieralisi@arm.com: updated commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org
PCI: layerscape: Fix wrong invocation of outbound window disable accessor 2018-11-20T11:09:51+00:00 Hou Zhiqiang Zhiqiang.Hou@nxp.com 2018-11-07T05:16:49+00:00 c6fd6fe9dea44732cdcd970f1130b8cc50ad685a The order of parameters is not correct when invoking the outbound window disable routine. Fix it. Fixes: 4a2745d760fa ("PCI: layerscape: Disable outbound windows configured by bootloader") Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com> [lorenzo.pieralisi@arm.com: commit log] Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: stable@vger.kernel.org 
The order of parameters is not correct when invoking the outbound
window disable routine. Fix it.

Fixes: 4a2745d760fa ("PCI: layerscape: Disable outbound windows configured by bootloader")
Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
[lorenzo.pieralisi@arm.com: commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org
PCI: imx6: Fix link training status detection in link up check 2018-11-20T11:09:34+00:00 Trent Piepho tpiepho@impinj.com 2018-11-05T18:11:36+00:00 68bc10bf992180f269816ff3d22eb30383138577 This bug was introduced in the interaction for two commits on either branch of the merge commit 562df5c8521e ("Merge branch 'pci/host-designware' into next"). Commit 4d107d3b5a68 ("PCI: imx6: Move link up check into imx6_pcie_wait_for_link()"), changed imx6_pcie_wait_for_link() to poll the link status register directly, checking for link up and not training, and made imx6_pcie_link_up() only check the link up bit (once, not a polling loop). While commit 886bc5ceb5cc ("PCI: designware: Add generic dw_pcie_wait_for_link()"), replaced the loop in imx6_pcie_wait_for_link() with a call to a new dwc core function, which polled imx6_pcie_link_up(), which still checked both link up and not training in a loop. When these two commits were merged, the version of imx6_pcie_wait_for_link() from 886bc5ceb5cc was kept, which eliminated the link training check placed there by 4d107d3b5a68. However, the version of imx6_pcie_link_up() from 4d107d3b5a68 was kept, which eliminated the link training check that had been there and was moved to imx6_pcie_wait_for_link(). The result was the link training check got lost for the imx6 driver. Eliminate imx6_pcie_link_up() so that the default handler, dw_pcie_link_up(), is used instead. The default handler has the correct code, which checks for link up and also that it still is not training, fixing the regression. Fixes: 562df5c8521e ("Merge branch 'pci/host-designware' into next") Signed-off-by: Trent Piepho <tpiepho@impinj.com> [lorenzo.pieralisi@arm.com: rewrote the commit log] Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Lucas Stach <l.stach@pengutronix.de> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Joao Pinto <Joao.Pinto@synopsys.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Richard Zhu <hongxing.zhu@nxp.com> 
This bug was introduced in the interaction for two commits on either
branch of the merge commit 562df5c8521e ("Merge branch
'pci/host-designware' into next").

Commit 4d107d3b5a68 ("PCI: imx6: Move link up check into
imx6_pcie_wait_for_link()"), changed imx6_pcie_wait_for_link() to poll
the link status register directly, checking for link up and not
training, and made imx6_pcie_link_up() only check the link up bit (once,
not a polling loop).

While commit 886bc5ceb5cc ("PCI: designware: Add generic
dw_pcie_wait_for_link()"), replaced the loop in
imx6_pcie_wait_for_link() with a call to a new dwc core function, which
polled imx6_pcie_link_up(), which still checked both link up and not
training in a loop.

When these two commits were merged, the version of
imx6_pcie_wait_for_link() from 886bc5ceb5cc was kept, which eliminated
the link training check placed there by 4d107d3b5a68. However, the
version of imx6_pcie_link_up() from 4d107d3b5a68 was kept, which
eliminated the link training check that had been there and was moved to
imx6_pcie_wait_for_link().

The result was the link training check got lost for the imx6 driver.

Eliminate imx6_pcie_link_up() so that the default handler,
dw_pcie_link_up(), is used instead. The default handler has the correct
code, which checks for link up and also that it still is not training,
fixing the regression.

Fixes: 562df5c8521e ("Merge branch 'pci/host-designware' into next")
Signed-off-by: Trent Piepho <tpiepho@impinj.com>
[lorenzo.pieralisi@arm.com: rewrote the commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Joao Pinto <Joao.Pinto@synopsys.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Richard Zhu <hongxing.zhu@nxp.com>
Revert "ACPI/PCI: Pay attention to device-specific _PXM node values" 2018-11-13T14:38:17+00:00 Bjorn Helgaas bhelgaas@google.com 2018-11-13T14:38:17+00:00 0d76bcc960e6057750fcf556b65da13f8bbdfd2b This reverts commit bad7dcd94f3956bcfc0a69ef71fdf0fcca3de4a8. bad7dcd94f39 ("ACPI/PCI: Pay attention to device-specific _PXM node values") caused boot failures (no console output at all) for Martin [1] and Ingo [2] on AMD ThreadRipper systems. Revert the commit until we figure out how to safely use these device-specific _PXM values. [1] https://lore.kernel.org/linux-pci/20180912152140.3676-2-Jonathan.Cameron@huawei.com [2] https://lore.kernel.org/linux-pci/20181113071712.GA2353@gmail.com Fixes: bad7dcd94f39 ("ACPI/PCI: Pay attention to device-specific _PXM node values") Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> 
This reverts commit bad7dcd94f3956bcfc0a69ef71fdf0fcca3de4a8.

bad7dcd94f39 ("ACPI/PCI: Pay attention to device-specific _PXM node
values") caused boot failures (no console output at all) for Martin [1]
and Ingo [2] on AMD ThreadRipper systems.

Revert the commit until we figure out how to safely use these
device-specific _PXM values.

[1] https://lore.kernel.org/linux-pci/20180912152140.3676-2-Jonathan.Cameron@huawei.com
[2] https://lore.kernel.org/linux-pci/20181113071712.GA2353@gmail.com
Fixes: bad7dcd94f39 ("ACPI/PCI: Pay attention to device-specific _PXM node values")
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>