Enable LTR for endpoints behind VMD

[Kai-Heng Feng]

[Impact]
PCIe links behind VMD may not be able to reach ASPM L1.2, because PCIe
Link Tolenrence Reporting doesn't get programmed with a sensible value.

[Fix]
Temporarily hardcode LTR value, which is used by Windows, for NVMe
devices behind VMD.

[Test]
With the patch applied, PCIe links can reach ASPM L1.2, hence the entire
Intel SoC can reach deeper power saving state.

[Regression Potential]
This patch targets specifically Intel Tigerlake VMD bridges, so there
won't be any regression since they are not on the market yet.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-focal' to 'verification-done-focal'. If the problem still exists, change the tag 'verification-needed-focal' to 'verification-failed-focal'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 5.8.0-20.21

---------------
linux (5.8.0-20.21) groovy; urgency=medium

  * groovy/linux: 5.8.0-20.21 -proposed tracker (LP: #1896668)

  * Lenovo ThinkBook 14-IML Touchpad not showing up in /proc/bus/input/devices
    (LP: #1853277)
    - i2c: core: Call i2c_acpi_install_space_handler() before
      i2c_acpi_register_devices()

  * Enable LTR for endpoints behind VMD (LP: #1896598)
    - SAUCE: PCI/ASPM: Enable LTR for endpoints behind VMD

  * Remove duplicated code in ip_defrag.sh of kselftests/net (LP: #1894062)
    - Revert "UBUNTU: SAUCE: selftests: net: ip_defrag: modprobe missing
      nf_defrag_ipv6 support"

  * [SRU] [Focal/OEM-5.6/Groovy]Fix AMD usb host controller lost after stress S3
    (LP: #1893914)
    - SAUCE: xhci: workaround for S3 issue on AMD SNPS 3.0 xHC

  * debian/rules editconfigs does not work on s390x to change s390x only configs
    (LP: #1863116)
    - [Packaging] kernelconfig -- only update/edit configurations on architectures
      we have compiler support

  * [Ubuntu 20.10] zPCI DMA tables and bitmap leak on hard unplug (PCI Event
    0x0304) (LP: #1896216)
    - s390/pci: fix leak of DMA tables on hard unplug

  * md: improve IO accounting (LP: #1891151)
    - md: improve io stats accounting

  * Groovy update: v5.8.10 upstream stable release (LP: #1896078)
    - ARM: OMAP2+: Fix an IS_ERR() vs NULL check in _get_pwrdm()
    - ARM: dts: logicpd-torpedo-baseboard: Fix broken audio
    - ARM: dts: logicpd-som-lv-baseboard: Fix broken audio
    - ARM: dts: logicpd-som-lv-baseboard: Fix missing video
    - regulator: push allocation in regulator_ena_gpio_request() out of lock
    - regulator: remove superfluous lock in regulator_resolve_coupling()
    - ARM: dts: socfpga: fix register entry for timer3 on Arria10
    - ARM: dts: omap5: Fix DSI base address and clocks
    - ARM: dts: ls1021a: fix QuadSPI-memory reg range
    - ARM: dts: imx7ulp: Correct gpio ranges
    - arm64: dts: imx: Add missing imx8mm-beacon-kit.dtb to build
    - ARM: dts: imx7d-zii-rmu2: fix rgmii phy-mode for ksz9031 phy
    - RDMA/rtrs-srv: Replace device_register with device_initialize and device_add
    - RDMA/rxe: Fix memleak in rxe_mem_init_user
    - RDMA/rxe: Drop pointless checks in rxe_init_ports
    - RDMA/rxe: Fix panic when calling kmem_cache_create()
    - RDMA/bnxt_re: Do not report transparent vlan from QP1
    - RDMA/bnxt_re: Fix the qp table indexing
    - RDMA/bnxt_re: Static NQ depth allocation
    - RDMA/bnxt_re: Fix driver crash on unaligned PSN entry address
    - RDMA/bnxt_re: Remove the qp from list only if the qp destroy succeeds
    - drm/sun4i: add missing put_device() call in sun8i_r40_tcon_tv_set_mux()
    - arm64: dts: imx8mq: Fix TMU interrupt property
    - drm/sun4i: Fix dsi dcs long write function
    - scsi: qla2xxx: Fix regression on sparc64
    - scsi: libsas: Set data_dir as DMA_NONE if libata marks qc as NODATA
    - drm/virtio: fix unblank
    - RDMA/core: Fix unsafe linked list traversal after failing to allocate CQ
    - RDMA/core: Fix reported speed and width
    - scsi: megaraid_sas: Don't call disable_irq from process IRQ poll
    - scsi: mpt3sas: Don'...

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux-oem-5.6 - 5.6.0-1031.32

---------------
linux-oem-5.6 (5.6.0-1031.32) focal; urgency=medium

  * Packaging resync (LP: #1786013)
    - update dkms package versions

  * CVE-2020-16119
    - SAUCE: dccp: avoid double free of ccid on child socket

  * CVE-2020-16120
    - ovl: pass correct flags for opening real directory
    - ovl: switch to mounter creds in readdir
    - ovl: verify permissions in ovl_path_open()
    - ovl: call secutiry hook in ovl_real_ioctl()
    - ovl: check permission to open real file

linux-oem-5.6 (5.6.0-1030.30) focal; urgency=medium

  * focal/linux-oem-5.6: 5.6.0-1030.30 -proposed tracker (LP: #1898714)

  * Fix broken e1000e device after S3 (LP: #1897755)
    - SAUCE: e1000e: Increase polling timeout on MDIC ready bit

  * Fix headset jack detection on Dell UFF desktops (LP: #1897508)
    - Revert "ALSA: hda: call runtime_allow() for all hda controllers"

  * [SRU][OEM-5.6]Fix AMD system hang after re-plugin USBC-DP dongle
    (LP: #1896716)
    - drm/amd/display: Move USB-C workaround to after parameter variables are set

  * alsa/hda: mic doesn't work on a HP AIO machine (LP: #1897694)
    - SAUCE: ALSA: hda/realtek - set mic to auto detect on a HP AIO machine

  * CVE-2020-26088
    - net/nfc/rawsock.c: add CAP_NET_RAW check.

  * HP Zbook Studio G7 boots into corrupted screen with PSR featured panel
    (LP: #1897501)
    - SAUCE: drm/i915/psr: allow overriding PSR disable param by quirk
    - SAUCE: drm/dp: add DP_QUIRK_FORCE_PSR_CHIP_DEFAULT quirk to CMN prod-ID
      19-15

linux-oem-5.6 (5.6.0-1029.29) focal; urgency=medium

  * focal/linux-oem-5.6: 5.6.0-1029.29 -proposed tracker (LP: #1895982)

  * linux-libc-dev in proposed cause seccomp_bpf from seccomp in
    ubuntu_kernel_selftests to fail on F-oem-5.6 (LP: #1896008)
    - seccomp: Fix ioctl number for SECCOMP_IOCTL_NOTIF_ID_VALID

  * Enable LTR for endpoints behind VMD (LP: #1896598)
    - SAUCE: PCI/ASPM: Enable LTR for endpoints behind VMD

  * CVE-2020-14385
    - xfs: fix boundary test in xfs_attr_shortform_verify

  * Fix non-working NVMe after S3 (LP: #1895718)
    - SAUCE: PCI: Enable ACS quirk on CML root port

  * CVE-2020-12655
    - xfs: add agf freeblocks verify in xfs_agf_verify

  * Thunderbolt3 daisy chain sometimes doesn't work (LP: #1895606)
    - thunderbolt: Retry DROM read once if parsing fails

  * CVE-2020-12656
    - sunrpc: svcauth_gss_register_pseudoflavor must reject duplicate
      registrations.
    - sunrpc: clean up properly in gss_mech_unregister()

  * CVE-2020-15393
    - usb: usbtest: fix missing kfree(dev->buf) in usbtest_disconnect

  * CVE-2020-12771
    - bcache: fix potential deadlock problem in btree_gc_coalesce

  * CVE-2020-15780
    - ACPI: configfs: Disallow loading ACPI tables when locked down

  * CVE-2020-16166
    - random32: update the net random state on interrupt and activity

  * Get the extended DPCD according to the related field in the DPCD registers.
    (LP: #1893752)
    - drm: move DP_MAX_DOWNSTREAM_PORTS from i915 to drm core
    - drm/i915/dp: Extract drm_dp_read_dpcd_caps()
    - SAUCE: drm/dp_mst: Retrieve extended DPCD caps for topology manager
...