linux/drivers
Johannes Thumshirn e42010d820 PCI: Set Read Completion Boundary to 128 iff Root Port supports it (_HPX)
Per PCIe spec r3.0, sec 2.3.1.1, the Read Completion Boundary (RCB)
determines the naturally aligned address boundaries on which a Read Request
may be serviced with multiple Completions:

  - For a Root Complex, RCB is 64 bytes or 128 bytes
    This value is reported in the Link Control Register

    Note: Bridges and Endpoints may implement a corresponding command bit
    which may be set by system software to indicate the RCB value for the
    Root Complex, allowing the Bridge/Endpoint to optimize its behavior
    when the Root Complex’s RCB is 128 bytes.

  - For all other system elements, RCB is 128 bytes

Per sec 7.8.7, if a Root Port only supports a 64-byte RCB, the RCB of all
downstream devices must be clear, indicating an RCB of 64 bytes.  If the
Root Port supports a 128-byte RCB, we may optionally set the RCB of
downstream devices so they know they can generate larger Completions.

Some BIOSes supply an _HPX that tells us to set RCB, even though the Root
Port doesn't have RCB set, which may lead to Malformed TLP errors if the
Endpoint generates completions larger than the Root Port can handle.

The IBM x3850 X6 with BIOS version -[A8E120CUS-1.30]- 08/22/2016 supplies
such an _HPX and a Mellanox MT27500 ConnectX-3 device fails to initialize:

  mlx4_core 0000:41:00.0: command 0xfff timed out (go bit not cleared)
  mlx4_core 0000:41:00.0: device is going to be reset
  mlx4_core 0000:41:00.0: Failed to obtain HW semaphore, aborting
  mlx4_core 0000:41:00.0: Fail to reset HCA
  ------------[ cut here ]------------
  kernel BUG at drivers/net/ethernet/mellanox/mlx4/catas.c:193!

After 6cd33649fa ("PCI: Add pci_configure_device() during enumeration")
and 7a1562d4f2 ("PCI: Apply _HPX Link Control settings to all devices
with a link"), we apply _HPX settings to *all* devices, not just those
hot-added after boot.

Before 7a1562d4f2, we didn't touch the Mellanox RCB, and the device
worked.  After 7a1562d4f2, we set its RCB to 128, and it failed.

Set the RCB to 128 iff the Root Port supports a 128-byte RCB.  Otherwise,
set RCB to 64 bytes.  This effectively ignores what _HPX tells us about
RCB.

Note that this change only affects _HPX handling.  If we have no _HPX, this
does nothing with RCB.

[bhelgaas: changelog, clear RCB if not set for Root Port]
Fixes: 6cd33649fa ("PCI: Add pci_configure_device() during enumeration")
Fixes: 7a1562d4f2 ("PCI: Apply _HPX Link Control settings to all devices with a link")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=187781
Tested-by: Frank Danapfel <fdanapfe@redhat.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Myron Stowe <myron.stowe@redhat.com>
CC: stable@vger.kernel.org	# v3.18+
2016-11-23 16:23:55 -06:00
..
accessibility
acpi More ACPI updates for v4.9-rc1 2016-10-14 12:50:05 -07:00
amba
android
ata ahci: qoriq: Revert "ahci: qoriq: Disable NCQ on ls2080a SoC" 2016-09-30 10:28:51 +02:00
atm
auxdisplay auxdisplay: img-ascii-lcd: driver for simple ASCII LCD displays 2016-10-06 17:03:41 +02:00
base memory-hotplug: fix store_mem_state() return value 2016-10-07 18:46:28 -07:00
bcma
block kthread: kthread worker API cleanup 2016-10-11 15:06:33 -07:00
bluetooth Bluetooth: btusb: Fix atheros firmware download error 2016-10-07 09:46:56 +02:00
bus ARM: SoC driver updates for v4.9 2016-10-07 21:23:40 -07:00
cdrom
char This adds a new gcc plugin named "latent_entropy". It is designed to 2016-10-15 10:03:15 -07:00
clk ARM: SoC: late DT updates for v4.9 2016-10-07 21:34:49 -07:00
clocksource ARM: SoC driver updates for v4.9 2016-10-07 21:23:40 -07:00
connector
cpufreq More power management updates for v4.9-rc1 2016-10-14 12:46:13 -07:00
cpuidle Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2016-10-15 09:26:12 -07:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2016-10-10 14:04:16 -07:00
dax Merge branch 'for-4.9/dax' into libnvdimm-for-next 2016-10-07 16:46:30 -07:00
dca
devfreq PM / devfreq: Skip status update on uninitialized previous_freq 2016-10-11 00:01:20 +02:00
dio
dma dmaengine updates for 4.8-rc1 2016-10-06 17:13:54 -07:00
dma-buf Merge tag 'drm-for-v4.9' of git://people.freedesktop.org/~airlied/linux 2016-10-11 18:12:22 -07:00
edac * Altera Arria10 enablement of NAND, DMA, USB, QSPI and SD-MMC FIFO 2016-10-04 12:06:26 -07:00
eisa
extcon
firewire
firmware ARM: SoC driver updates for v4.9 2016-10-07 21:23:40 -07:00
fmc
fpga
gpio gpio: pca953x: add a comment explaining the need for a lockdep subclass 2016-10-11 23:17:08 +02:00
gpu Merge tag 'drm-for-v4.9' of git://people.freedesktop.org/~airlied/linux 2016-10-11 18:12:22 -07:00
hid Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid 2016-10-07 11:58:38 -07:00
hsi
hv Drivers: hv: get rid of id in struct vmbus_channel 2016-09-27 12:35:49 +02:00
hwmon hwmon updates for v4.9 2016-10-04 10:56:14 -07:00
hwspinlock
hwtracing
i2c i2c: 'i2c-bus' node support for v4.8-rc1 2016-10-11 23:37:26 +02:00
ide
idle nmi_backtrace: generate one-line reports for idle cpus 2016-10-07 18:46:30 -07:00
iio Staging/IIO patches for 4.9-rc1 2016-10-05 14:50:51 -07:00
infiniband Merge of the qedr RoCE driver 2016-10-14 13:43:08 -07:00
input Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2016-10-14 13:19:30 -07:00
iommu IOMMU Updates for Linux v4.9 2016-10-11 12:52:41 -07:00
ipack
irqchip Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2016-10-15 09:26:12 -07:00
isdn
leds
lguest
lightnvm Merge branch 'for-4.9/block' of git://git.kernel.dk/linux-block 2016-10-07 14:42:05 -07:00
macintosh
mailbox Merge branch 'mailbox-for-next' of git://git.linaro.org/landing-teams/working/fujitsu/integration 2016-10-06 17:36:53 -07:00
mcb mcb: Add a dma_device to mcb_device 2016-09-27 12:33:47 +02:00
md kthread: kthread worker API cleanup 2016-10-11 15:06:33 -07:00
media linux-kselftest-4.9-rc1-update 2016-10-14 15:17:12 -07:00
memory ARM: SoC driver updates for v4.9 2016-10-07 21:23:40 -07:00
memstick
message
mfd - Core Frameworks 2016-10-07 08:35:35 -07:00
misc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
mmc USB/PHY/EXTCON patches for 4.9-rc1 2016-10-03 20:17:35 -07:00
mtd Merge branch 'akpm' (patches from Andrew) 2016-10-11 17:34:10 -07:00
net Merge of the qedr RoCE driver 2016-10-14 13:43:08 -07:00
nfc
ntb
nubus
nvdimm Merge branch 'for-4.9/dax' into libnvdimm-for-next 2016-10-07 16:46:30 -07:00
nvme nvme: use the DMA_ATTR_NO_WARN attribute 2016-10-11 15:06:32 -07:00
nvmem ARM: SoC driver updates for v4.9 2016-10-07 21:23:40 -07:00
of Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2016-10-15 09:26:12 -07:00
oprofile Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
parisc
parport
pci PCI: Set Read Completion Boundary to 128 iff Root Port supports it (_HPX) 2016-11-23 16:23:55 -06:00
pcmcia
perf ARM: SoC driver updates for v4.9 2016-10-07 21:23:40 -07:00
phy
pinctrl ARM: SoC driver updates for v4.9 2016-10-07 21:23:40 -07:00
platform platform-drivers-x86 for 4.9-1 2016-10-13 16:52:39 -07:00
pnp
power power supply and reset changes for the v4.9 series 2016-10-06 18:21:15 -07:00
powercap
pps pps: kc: fix non-tickless system config dependency 2016-10-11 15:06:32 -07:00
ps3
ptp drivers/ptp: Fix kernel memory disclosure 2016-10-13 10:20:06 -04:00
pwm
rapidio rapidio/rio_cm: use memdup_user() instead of duplicating code 2016-10-11 15:06:32 -07:00
ras
regulator Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux 2016-10-12 11:05:23 -07:00
remoteproc rpmsg updates for v4.9 2016-10-06 17:03:49 -07:00
reset
rpmsg
rtc RTC for 4.9 2016-10-14 13:13:44 -07:00
s390 SCSI misc on 20161006 2016-10-07 09:28:53 -07:00
sbus
scsi SCSI misc on 20161014 2016-10-14 11:37:50 -07:00
sfi
sh
sn
soc powerpc updates for 4.9 #2 2016-10-14 11:07:42 -07:00
spi kthread: kthread worker API cleanup 2016-10-11 15:06:33 -07:00
spmi spmi: pmic-arb: Return an error code if sanity check fails 2016-09-27 12:43:34 +02:00
ssb
staging Merge branch 'akpm' (patches from Andrew) 2016-10-11 17:34:10 -07:00
target
tc
thermal Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux 2016-10-12 11:05:23 -07:00
thunderbolt
tty kthread: kthread worker API cleanup 2016-10-11 15:06:33 -07:00
uio
usb Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2016-10-15 09:26:12 -07:00
uwb
vfio vfio_pci: use pci_alloc_irq_vectors 2016-09-29 13:36:38 -06:00
vhost
video Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2016-10-15 09:26:12 -07:00
virt
virtio
vlynq
vme vme: fake: remove unexpected unlock in fake_master_set() 2016-09-27 12:43:35 +02:00
w1
watchdog Merge git://www.linux-watchdog.org/linux-watchdog 2016-10-13 16:44:20 -07:00
xen xen: features and fixes for 4.9-rc0 2016-10-06 11:19:10 -07:00
zorro
Kconfig
Makefile