Add Altera Arria10 Ethernet FIFO memory EDAC support. Update to support
a common compatibility string for all Ethernet FIFOs in the DT.
Signed-off-by: NThor Thayer <tthayer@opensource.altera.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1466603939-7526-8-git-send-email-tthayer@opensource.altera.comSigned-off-by: NBorislav Petkov <bp@suse.de>

In preparation for additional memory module ECCs, add the memory
initialization functions and helpers.
Signed-off-by: NThor Thayer <tthayer@opensource.altera.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1466603939-7526-7-git-send-email-tthayer@opensource.altera.comSigned-off-by: NBorislav Petkov <bp@suse.de>

Make the IRQ and check_deps() functions available to all the memory
buffers by moving them outside of the OCRAM only area.
Signed-off-by: NThor Thayer <tthayer@opensource.altera.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1466603939-7526-5-git-send-email-tthayer@opensource.altera.comSigned-off-by: NBorislav Petkov <bp@suse.de>

In preparation for additional memory module ECCs, the IRQ function will
check a panic flag before doing a kernel panic on double bit errors.

OCRAM uncorrectable errors cause a panic because sleep/resume functions
and FPGA contents during sleep are stored in OCRAM.

ECCs on peripheral FIFO buffers will not cause a kernel panic on DBERRs
because the packet can be retried and therefore recovered.
Signed-off-by: NThor Thayer <tthayer@opensource.altera.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1466603939-7526-3-git-send-email-tthayer@opensource.altera.comSigned-off-by: NBorislav Petkov <bp@suse.de>

In preparation for the Arria10 ECC modules, check the status of the
parent in the device tree to ensure the block is enabled. Skip if no
parent phandle is set in the device tree.
Signed-off-by: NThor Thayer <tthayer@opensource.altera.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1466603939-7526-2-git-send-email-tthayer@opensource.altera.comSigned-off-by: NBorislav Petkov <bp@suse.de>

The device private data structures are used only here so make them
static.
Signed-off-by: NThor Thayer <tthayer@opensource.altera.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1466603939-7526-4-git-send-email-tthayer@opensource.altera.comSigned-off-by: NBorislav Petkov <bp@suse.de>

c44696ff ("EDAC: Remove arbitrary limit on number of channels")
lifted the arbitrary limit on memory controller channels in EDAC.
However, the dynamic channel attributes dynamic_csrow_dimm_attr and
dynamic_csrow_ce_count_attr remained 6.

This wasn't a problem except channels 6 and 7 weren't visible in sysfs
on machines with more than 6 channels after the conversion to static
attr groups with

  2c1946b6 ("EDAC: Use static attribute groups for managing sysfs entries")

 [ without that, we're exploding in edac_create_sysfs_mci_device()
   because we're dereferencing out of the bounds of the
   dynamic_csrow_dimm_attr array. ]

Add attributes for channels 6 and 7 along with a guard for the
future, should more channels be required and/or to sanity check for
misconfigured machines.

We still need to check against the number of channels present on the MC
first, as Thor reported.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Reported-by: NHironobu Ishii <ishii.hironobu@jp.fujitsu.com>
Tested-by: NThor Thayer <tthayer@opensource.altera.com>
Cc: <stable@vger.kernel.org> # 4.2

It is useless to do it if we're loaded on unsupported hardware so do
that only after we have detected at least 1 supported AMD northbridge.
Signed-off-by: NBorislav Petkov <bp@suse.de>

Separate the device match arrays for each platform to prevent CycloneV
matches when calling of_platform_populate() on the Arria10 ECC manager
node.

If the SDRAM is a child node of ECC manager, call probe function via
of_platform_populate().
Signed-off-by: NThor Thayer <tthayer@opensource.altera.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1464193783-5071-4-git-send-email-tthayer@opensource.altera.comSigned-off-by: NBorislav Petkov <bp@suse.de>

To better support child devices, the ECC manager needs to be
implemented as an IRQ controller.
Signed-off-by: NThor Thayer <tthayer@opensource.altera.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1465331757-10227-1-git-send-email-tthayer@opensource.altera.comSigned-off-by: NBorislav Petkov <bp@suse.de>

The /dev/ptmx device node is changed to lookup the directory entry "pts"
in the same directory as the /dev/ptmx device node was opened in.  If
there is a "pts" entry and that entry is a devpts filesystem /dev/ptmx
uses that filesystem.  Otherwise the open of /dev/ptmx fails.

The DEVPTS_MULTIPLE_INSTANCES configuration option is removed, so that
userspace can now safely depend on each mount of devpts creating a new
instance of the filesystem.

Each mount of devpts is now a separate and equal filesystem.

Reserved ttys are now available to all instances of devpts where the
mounter is in the initial mount namespace.

A new vfs helper path_pts is introduced that finds a directory entry
named "pts" in the directory of the passed in path, and changes the
passed in path to point to it.  The helper path_pts uses a function
path_parent_directory that was factored out of follow_dotdot.

In the implementation of devpts:
 - devpts_mnt is killed as it is no longer meaningful if all mounts of
   devpts are equal.
 - pts_sb_from_inode is replaced by just inode->i_sb as all cached
   inodes in the tty layer are now from the devpts filesystem.
 - devpts_add_ref is rolled into the new function devpts_ptmx.  And the
   unnecessary inode hold is removed.
 - devpts_del_ref is renamed devpts_release and reduced to just a
   deacrivate_super.
 - The newinstance mount option continues to be accepted but is now
   ignored.

In devpts_fs.h definitions for when !CONFIG_UNIX98_PTYS are removed as
they are never used.

Documentation/filesystems/devices.txt is updated to describe the current
situation.

This has been verified to work properly on openwrt-15.05, centos5,
centos6, centos7, debian-6.0.2, debian-7.9, debian-8.2, ubuntu-14.04.3,
ubuntu-15.10, fedora23, magia-5, mint-17.3, opensuse-42.1,
slackware-14.1, gentoo-20151225 (13.0?), archlinux-2015-12-01.  With the
caveat that on centos6 and on slackware-14.1 that there wind up being
two instances of the devpts filesystem mounted on /dev/pts, the lower
copy does not end up getting used.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg KH <greg@kroah.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Serge Hallyn <serge.hallyn@ubuntu.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Cc: Jann Horn <jann@thejh.net>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Florian Weimer <fw@deneb.enyo.de>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

pmu->irq_affinity will not be freed if an error occurred within
arm_pmu_device_probe after of_pmu_irq_cfg has been called.

Note that in the case of_pmu_irq_cfg is returning an error,
pmu->irq_affinity will not be set, but it should be NULL as pmu was
kzalloc'd. Therefore the result kfree(NULL) is benign.
Signed-off-by: NJulien Grall <julien.grall@arm.com>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

The global variable __oprofile_cpu_pmu is set before the PMU is fully
initialized. If an error occurs before the end of the initialization,
the PMU will be freed and the variable will contain an invalid pointer.

This will result in a kernel crash when perf will be used.

Fix it by moving the setting of __oprofile_cpu_pmu when the PMU is fully
initialized (i.e when it is no longer possible to fail).

Cc: <stable@vger.kernel.org>
Signed-off-by: NJulien Grall <julien.grall@arm.com>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

The only function called by of_pmu_irq_cfg that will increment the
reference count on dn is of_parse_phandle.

Each time we successfully parse a possible CPU from an
interrupt-affinity property, we increment the refcount of that CPU node
once via of_parse_handle. After validating the CPU is possible, we
decrement the refcount once. Subsequently, we decrement the refcount
again, either as part of an early break if we don't have a matching SPI,
or as part of the end of the loop body.

This will lead to decrementing twice the refcounnt.
Remove the second pairs of call to of_node_put as nobody is using dn
between the first and second call to of_node_put.
Signed-off-by: NJulien Grall <julien.grall@arm.com>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Signed-off-by: NDave Airlie <airlied@redhat.com>

The wrong external interrupt bits are being set, offset by 1.
Signed-off-by: NJoshua Henderson <digitalpeer@digitalpeer.com>
Signed-off-by: NPurna Chandra Mandal <purna.mandal@microchip.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

The erratum fixes the hang of ITS SYNC command by avoiding inter node
io and collections/cpu mapping on thunderx dual-socket platform.

This fix is only applicable for Cavium's ThunderX dual-socket platform.
Reviewed-by: NRobert Richter <rrichter@cavium.com>
Signed-off-by: NGanapatrao Kulkarni <gkulkarni@caviumnetworks.com>
Signed-off-by: NRobert Richter <rrichter@cavium.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Make sure the two sides of the bitwise operation are bool.
Signed-off-by: NAndrew Jones <drjones@redhat.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

drm_fb_cma code has a nice helper function to display in the debugfs
information about the underlying framebuffers used by HDLCD:

$ cat /sys/kernel/debug/dri/0/fb
fb: 1920x1200@XR24
   0: offset=0 pitch=7680, obj:  0 ( 2) 001011ba 0x00000000fc300000 ffffff800a27c000 9338880
fb: 1920x1200@XR24
   0: offset=0 pitch=7680, obj:  0 ( 2) 001008ca 0x00000000fba00000 ffffff8009987000 9338880
fb: 1920x1200@XR24
   0: offset=0 pitch=7680, obj:  0 ( 1) 00100000 0x00000000fb100000 ffffff8008fdc000 9216000

Add the entry in HDLCD's debugfs node.
Signed-off-by: NLiviu Dudau <Liviu.Dudau@arm.com>

Harden the plane_check() code to drop attempts at scaling because
that is not supported. Make hdlcd_plane_atomic_update() set the pitch
and line length registers that correctly reflect the plane's values.
And make hdlcd_crtc_mode_set_nofb() a helper function for
hdlcd_crtc_enable() rather than an exposed hook.

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NLiviu Dudau <Liviu.Dudau@arm.com>

event_list just reimplemented what drm_crtc_arm_vblank_event does. And
we also need to send out drm events when shutting down a pipe.

With this it's possible to use the new nonblocking commit support in
the helpers.
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Acked-by: NLiviu Dudau <Liviu.Dudau@arm.com>

Because the HDLCD driver acts as a component master it can end
up enabling the runtime PM functionality before the encoders
are initialised. This can cause crashes if the component slave
never probes (missing module) or if the PM operations kick in
before the probe finishes.

Move the enabling of the runtime PM after the component master
has finished collecting the slave components and use the DRM
atomic helpers to suspend and resume the device.
Tested-by: NRobin Murphy <Robin.Murphy@arm.com>
Signed-off-by: NLiviu Dudau <Liviu.Dudau@arm.com>

Now the the HS-DDR mode clock timings have been corrected, we can
re-enable these modes on the A80.
Signed-off-by: NChen-Yu Tsai <wens@csie.org>
Acked-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

The MMC clock timings were incorrectly calculated, when the conversion
from delay value to delay phase was done.

The 50M DDR and 50M DDR 8bit timings are off, and make eMMC DDR
unusable. Unfortunately it seems different controllers on the same SoC
have different timings. The new settings are taken from mmc2, which is
commonly used with eMMC.

The settings for the slower timing modes seem to work despite being
wrong, so leave them be.
Signed-off-by: NChen-Yu Tsai <wens@csie.org>
Acked-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

When IS_ERR_VALUE was removed from the mmc core code, it was replaced
with a simple not-zero check. This does not work, as the value checked
is the return value for mmc_select_bus_width, which returns the set
bit width on success. This made eMMC modes higher than HS-DDR unusable.

Fix this by checking for a positive return value instead.

Fixes: 287980e4 ("remove lots of IS_ERR_VALUE abuses")
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: NChen-Yu Tsai <wens@csie.org>
Acked-by: NHans de Goede <hdegoede@redhat.com>
Reviewed-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: NJaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: NShawn Lin <shawn.lin@rock-chips.com>
Tested-by: NMarcel Ziswiler <marcel.ziswiler@toradex.com>
Tested-by: NBjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Roland Dreier reports that one of his systems cannot boot because of
the changes made by commit ac212b69 (ACPI / processor: Use common
hotplug infrastructure).

The problematic part of it is the request_region() call in
acpi_processor_get_info() that used to run at module init time before
the above commit and now it runs much earlier.  Unfortunately, the
region(s) reserved by it fall into a range the PCI subsystem attempts
to reserve for AHCI IO BARs.  As a result, the PCI reservation fails
and AHCI doesn't work, while previously the PCI reservation would
be made before acpi_processor_get_info() and it would succeed.

That request_region() call, however, was overlooked by commit
ac212b69, as it is not necessary for the enumeration of the
processors.  It only is needed when the ACPI processor driver
actually attempts to handle them which doesn't happen before
loading the ACPI processor driver module.  Therefore that call
should have been moved from acpi_processor_get_info() into that
module.

Address the problem by moving the request_region() call in question
out of acpi_processor_get_info() and use the observation that the
region reserved by it is only needed if the FADT-based CPU
throttling method is going to be used, which means that it should
be sufficient to invoke it from acpi_processor_get_throttling_fadt().

Fixes: ac212b69 (ACPI / processor: Use common hotplug infrastructure)
Reported-by: NRoland Dreier <roland@purestorage.com>
Tested-by: NRoland Dreier <roland@purestorage.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The address check in acpi_hw_get_access_bit_width() should be byte width
based, not bit width based. This patch fixes this mistake.

For those who want to review acpi_hw_access_bit_width(), here is the
concerns and the design details of the function:

It is supposed that the GAS Address field should be aligned to the byte
width indicated by the GAS AccessSize field. Similarly, for the old non
GAS register, it is supposed that its Address should be aligned to its
Length.

For the "AccessSize = 0 (meaning ANY)" case, we try to return the maximum
instruction width (64 for MMIO or 32 for PIO) or the user expected access
bit width (64 for acpi_read()/acpi_write() or 32 for acpi_hw_read()/
acpi_hw_write()) and it is supposed that the GAS Address field should
always be aligned to the maximum expected access bit width (otherwise it
can't be accessed using ANY access bit width).

The problem is in acpi_tb_init_generic_address(), where the non GAS
register's Length is converted into the GAS BitWidth field, its Address is
converted into the GAS Address field, and the GAS AccessSize field is left
0 but most of the registers actually cannot be accessed using "ANY"
accesses.

As a conclusion, when AccessSize = 0 (ANY), the Address should either be
aligned to the BitWidth (wrong conversion) or aligned to 32 for PIO or 64
for MMIO (real GAS). Since currently, max_bit_width is 32, then:
1. BitWidth for the wrong conversion is 8,16,32; and
2. The Address of the real GAS should always be aligned to 8,16,32.
The address alignment check to exclude false matched real GAS is not
necessary. Thus this patch fixes the issue by removing the address
alignment check.

On the other hand, we in fact could use a simpler check of
"reg->bit_width < max_bit_width" to exclude the "BitWidth=64 PIO" case that
may be issued from acpi_read()/acpi_write() in the future.

Fixes: b314a172 (ACPICA: Hardware: Add optimized access bit width support)
Reported-and-tested-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: NMike Marshall <hubcap@omnibond.com>
Suggested-by: NJan Beulich <jbeulich@suse.com>
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The return value of clamp_val() has to be stored actually.

Fixes: b7898fda (cpufreq: Support for fast frequency switching)
Reported-by: NSteve Muckle <steve.muckle@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>

Connectors are unregistered by mtk_drm_drv via drm_connector_unregister_all().
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

Do not try to dereference dpi if it is NULL.
Since dpi can never be NULL when mtk_dpi_set_display_mode() is called,
remove the message.
Reported-by: NHeinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

If kmalloc() returned NULL we would end up dereferencing "state" a
couple lines later.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

Reset crtc->state to NULL after freeing the state object and call
__drm_atomic_helper_crtc_destroy_state() helper instead of manually
calling drm_property_unreference_blob().
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

- Fixed black screen for some resolutions of G200e rev4
- Fixed testm & testn which had predetermined value.
Reported-by: NJan Beulich <jbeulich@suse.com>
Signed-off-by: NMathieu Larouche <mathieu.larouche@matrox.com>
Cc: stable@vger.kernel.org
Signed-off-by: NDave Airlie <airlied@redhat.com>

Since the introduction of (struct_mutex) lockless GEM bo freeing, there
are a pair of driver vfuncs for freeing the GEM bo, of which the driver
may choose to only implement driver->gem_object_free_unlocked (and so
avoid taking the struct_mutex along the free path). However, the CMA GEM
helpers were still calling driver->gem_free_object directly, now NULL,
and promptly dying on the fancy new lockless drivers. Oops.

Robert Foss bisected this to b82caafc (drm/vc4: Use lockless gem BO
free callback) on his vc4 device, but that just serves as an enabler for
9f0ba539 (drm/gem: support BO freeing without dev->struct_mutex).
Reported-by: NRobert Foss <robert.foss@collabora.com>
Fixes: 9f0ba539 (drm/gem: support BO freeing without dev->struct_mutex)
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Robert Foss <robert.foss@collabora.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: Alex Deucher <alexdeucher@gmail.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: stable@vger.kernel.org
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Tested-by: NRobert Foss <robert.foss@collabora.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

After commit 027b3f8b ("drm/modes: stop
handling framebuffer special") extra fb refs are left around when doing
atomic modesetting.

The problem is that the new drm_property_change_valid_get() does not
return anything in the '**ref' parameter, which causes
drm_property_change_valid_put() to do nothing.

For some reason this doesn't cause problems with legacy API.

Also, previously the code only set the 'ref' variable for fbs, with this
patch the 'ref' is set for all objects.

Fixes: 027b3f8b ("drm/modes: stop handling framebuffer special")
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDave Airlie <airlied@redhat.com>

drm_atomic_set_mode_prop_for_crtc() does not clear the state->mode, so
old data may be left there when a new mode is set, possibly causing odd
issues.

This patch improves the situation by always clearing the state->mode
first.
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
Cc: stable@vger.kernel.org
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Commit 652353e6 ("drm/sti: set CRTC
modesetting parameters") added a hack to avoid warnings related to
setting mode with atomic API. With the previous patch, the hack should
no longer be necessary.
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Vincent Abriou <vincent.abriou@st.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDave Airlie <airlied@redhat.com>

When setting mode via MODE_ID property,
drm_atomic_set_mode_prop_for_crtc() does not call
drm_mode_set_crtcinfo() which possibly causes:

"[drm:drm_calc_timestamping_constants [drm]] *ERROR* crtc 32: Can't
calculate constants, dotclock = 0!"

Whether the error is seen depends on the previous data in state->mode,
as state->mode is not cleared when setting new mode.

This patch adds drm_mode_set_crtcinfo() call to
drm_mode_convert_umode(), which is called in both legacy and atomic
paths. This should be fine as there's no reason to call
drm_mode_convert_umode() without also setting the crtc related fields.

drm_mode_set_crtcinfo() is removed from the legacy drm_mode_setcrtc() as
that is no longer needed.
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@vger.kernel.org
Signed-off-by: NDave Airlie <airlied@redhat.com>

Otherwise we get confused when two flows on different channels get the
 same flow ID.
Signed-off-by: NEdward Cree <ecree@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The size of the VPD area is not necessarily 4-byte aligned, so a
pci_vpd_read() might return less than 4 bytes.  Zero our buffer and
accept anything other than an error.  Intel X710 NICs exercise this.

Fixes: 4e1a6355 ("vfio/pci: Use kernel VPD access functions")
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>