[SRU][OEM-5.6]Fix AMD system hang after re-plugin USBC-DP dongle

[AaronMa]

[Impact]
After much times of re-plug USBC-DP dongle with external monitor,
AMD laptop will hang.

[Fix]
AMD GPU driver set the wrong link setting to DP port.
After initialize the DP setting, DP works fine.

[Test Case]
Verified on the target platform. no hang again.

[Regression Potential]
Low,
Upstream fix in 5.7 kernel, Verified with positive results.
Groovy already got this fix.

[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!

[AaronMa (mapengyu)]

Tested on oem-5.6.0-1030, the issue is fixed.

[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
...