arm64: snapdragon: reduce boot noise
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Incomplete
|
Undecided
|
Unassigned | ||
Bionic |
Fix Released
|
Undecided
|
Unassigned | ||
Cosmic |
Won't Fix
|
Undecided
|
Unassigned |
Bug Description
Impact:
During boot on a Dragonboard410c using a recent Bionic or Cosmic kernel, there's some noise like:
...
[ 3.665431] msm_dsi_phy 1a98300.dsi-phy: Failed to get supply 'vddio': -517
[ 3.669243] msm_dsi_phy 1a98300.dsi-phy: dsi_phy_
[ 3.676180] msm_dsi_phy 1a98300.dsi-phy: dsi_phy_
...
or
...
[ 4.192280] qcom,pm8916-
[ 4.195660] qcom,pm8916-
...
and similar.
This is mainly due to DRM_MSM* and SND_QCOM_MSM* that were built-in, and tries to initialize before the voltage regulators are ready to work, resulting in a noisy bootlog.
These patches factor out some code as modules, so when the kmods are loaded and initialized, regulators are already present and ready to attach - all these config changes shave around ~3K bytes from dmesg, making the bootlog easir to parse.
Fix:
Apply the attached patches and recompile
How to test:
Boot a patched kernel and check for the above noise in dmesg
Regression potential:
None, we are just turning some code into kmods, and turning off a couple of not used feature for this flavour - all the other flavours are untouched.
CVE References
description: | updated |
Changed in linux (Ubuntu Bionic): | |
status: | New → Fix Committed |
tags: |
added: verification-done-bionic removed: verification-needed-bionic |
tags: | added: cscc |
This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:
apport-collect 1797154
and then change the status of the bug to 'Confirmed'.
If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.
This change has been made by an automated script, maintained by the Ubuntu Kernel Team.