[SRU][Eoan][PATCH 0/1] Fix the crash of sof driver in the -41 kernel

[Hui Wang]

BugLink: http://bugs.launchpad.net/bugs/1864061

In the -41 kernel, we introduced a patch from stable kernel, that
make the sof driver crash, and there is a fix patch in the 5.6-rc1,
and this fix patch is already in the stable and is merged to focal
kernel, now we backport this patch to Eoan kernel if -42 doesn't
introduce this fix patch from stable.

The patch introduced the crash:
commit 063821115e02229d5fd3de31bad270d5e30aeb41
Author: Dragos Tarcatu <dragos_tarcatu at mentor.com>
Date: Mon Dec 9 18:39:38 2019 -0600

    ASoC: topology: Check return value for snd_soc_add_dai_link()

    BugLink: https://bugs.launchpad.net/bugs/1861929

    [ Upstream commit 76d2703649321c296df7ec0dafd50add96215de4 ]

    snd_soc_add_dai_link() might fail. This situation occurs for
    instance in a very specific use case where a PCM device and a
    Back End DAI link are given identical names in the topology.
    When this happens, soc_new_pcm_runtime() fails and then
    snd_soc_add_dai_link() returns -ENOMEM when called from
    soc_tplg_fe_link_create(). Because of that, the link will not
    get added into the card list, so any attempt to remove it later
    ends up in a panic.

    Fix that by checking the return status and free the memory in case
    of an error.

    Reviewed-by: Ranjani Sridharan <ranjani.sridharan at linux.intel.com>
    Signed-off-by: Dragos Tarcatu <dragos_tarcatu at mentor.com>
    Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
    Link: https://lore.kernel.org/r/20191210003939.15752-2-pierre-louis.bossart@linux.intel.com
    Signed-off-by: Mark Brown <broonie at kernel.org>
    Signed-off-by: Sasha Levin <sashal at kernel.org>
    Signed-off-by: Kamal Mostafa <kamal at canonical.com>
    Signed-off-by: Khalid Elmously <khalid.elmously at canonical.com>


[Impact]
During the boot, the sof driver crash because the hdmi_pcm_list
is not initialized before it is used.

[Fix]
This bug is fixed in the mainline kernel v5.6-rc1, now backport
this patch to ubuntu kernel

[Test Case]
Boot the -41 kernel with this patch added.
blacklist the snd_soc_skl
the kernel can boot successfully, and sof driver worked well

[Regression Risk]
Low, the patches are backported from upstream kernel, and I tested
this patch on Lenovo and Dell dmic machines. Focal kernel already
has this patch and works well.


Jaroslav Kysela (1):
  ASoC: topology: fix soc_tplg_fe_link_create() - link->dobj
    initialization order

 sound/soc/soc-topology.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

-- 
2.17.1