alsa/hdmi: the hdmi audio stops working from Ubuntu-4.4.0-155.182

[Hui Wang]

[Impact]
We had a Dell machine, this machine was enabled with ubuntu 4.4
kernel before, but recently the hdmi audio on this machine stopped
working with the latest ubuntu 4.4. kernel. The system can't detect
its plugging and can't output sound to it anymore.

[Fix]
This is because we backported a patch from stable updates, and that
patch is for v5.2 kernel, if we backported it to 4.4 kernel, we need
to do some change, and also we need to backport one more patch from
stabe kernel.

[Test Case]
Connect a monitor to the machine and boot up, after booting up, we
could see the hdmi audio is found, and play sound to the hdmi audio,
we could hear the sound from monitor.

[Regression Risk]
It is possible to make the hdmi audio fail to work after applying this
patchset, like the hdmi audio can't be detected after plugging a hdmi
monitor. But this possibility is very low, we tested the patchset on
many dell and lenovo machines, all worked well.

[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-xenial' to 'verification-done-xenial'. If the problem still exists, change the tag 'verification-needed-xenial' to 'verification-failed-xenial'.

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!

[Hui Wang (hui.wang)]

The -proposed kernel (4.4.0-191-generic) can fix this issue.

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 4.4.0-193.224

---------------
linux (4.4.0-193.224) xenial; urgency=medium

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

linux (4.4.0-192.222) xenial; urgency=medium

  * xenial/linux: 4.4.0-192.222 -proposed tracker (LP: #1897734)

  * mwifiex stops working after kernel upgrade (LP: #1897299)
    - mwifiex: Increase AES key storage size to 256 bits

  * xenial 4.4.0-191-generic in -proposed has a regression (LP: #1896725)
    - Revert "XEN uses irqdesc::irq_data_common::handler_data to store a per
      interrupt XEN data pointer which contains XEN specific information."

linux (4.4.0-191.221) xenial; urgency=medium

  * xenial/linux: 4.4.0-191.221 -proposed tracker (LP: #1896067)

  * Novalink (mkvterm command failure) (LP: #1892546)
    - tty: hvcs: Don't NULL tty->driver_data until hvcs_cleanup()

  * Xenial update: v4.4.236 upstream stable release (LP: #1895891)
    - HID: core: Correctly handle ReportSize being zero
    - HID: core: Sanitize event code and type when mapping input
    - perf record/stat: Explicitly call out event modifiers in the documentation
    - mm, page_alloc: remove unnecessary variable from free_pcppages_bulk
    - hwmon: (applesmc) check status earlier.
    - ceph: don't allow setlease on cephfs
    - s390: don't trace preemption in percpu macros
    - xen/xenbus: Fix granting of vmalloc'd memory
    - dmaengine: of-dma: Fix of_dma_router_xlate's of_dma_xlate handling
    - batman-adv: Avoid uninitialized chaddr when handling DHCP
    - batman-adv: bla: use netif_rx_ni when not in interrupt context
    - dmaengine: at_hdmac: check return value of of_find_device_by_node() in
      at_dma_xlate()
    - netfilter: nf_tables: incorrect enum nft_list_attributes definition
    - netfilter: nf_tables: fix destination register zeroing
    - dmaengine: pl330: Fix burst length if burst size is smaller than bus width
    - bnxt_en: Check for zero dir entries in NVRAM.
    - fix regression in "epoll: Keep a reference on files added to the check list"
    - tg3: Fix soft lockup when tg3_reset_task() fails.
    - iommu/vt-d: Serialize IOMMU GCMD register modifications
    - thermal: ti-soc-thermal: Fix bogus thermal shutdowns for omap4430
    - include/linux/log2.h: add missing () around n in roundup_pow_of_two()
    - btrfs: drop path before adding new uuid tree entry
    - btrfs: Remove redundant extent_buffer_get in get_old_root
    - btrfs: Remove extraneous extent_buffer_get from tree_mod_log_rewind
    - btrfs: set the lockdep class for log tree extent buffers
    - uaccess: Add non-pagefault user-space read functions
    - uaccess: Add non-pagefault user-space write function
    - btrfs: fix potential deadlock in the search ioctl
    - net: qmi_wwan: MDM9x30 specific power management
    - net: qmi_wwan: support "raw IP" mode
    - net: qmi_wwan: should hold RTNL while changing netdev type
    - net: qmi_wwan: ignore bogus CDC Union descriptors
    - Add Dell Wireless 5809e Gobi 4G HSPA+ Mobile Broadband Card (rev3) to
      qmi_wwan
    - qmi_wwan: Added support for Gemalto's Cinterion PHxx WWAN interface
    - qmi_wwan: add support for Quec...