Additional regression in CMA allocation rework

Bug #1841483 reported by dann frazier on 2019-08-26
This bug affects 1 person
Affects Status Importance Assigned to Milestone
linux (Ubuntu)
dann frazier
dann frazier

Bug Description

Introduced by the fixes for bug 1823753. Also related - bug 1839395.

There is an upstream report that the CMA allocation rework we backported to disco is breaking the ath10k wireless driver - and possibly other drivers - in certain configs. It is not clear if Ubuntu users have been impacted by this regression, I just noticed that it has a Fixes: reference in the git commit.

[Test Case]
Regression tested only.

90ae409f9eb3b dma-direct: fix zone selection after an unaddressable CMA allocation

[Regression Risk]
Regressions in this code generally cause drivers to fail due to unavailable memory.

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 1841483

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.

Changed in linux (Ubuntu):
status: New → Incomplete
dann frazier (dannf) on 2019-08-26
Changed in linux (Ubuntu):
status: Incomplete → In Progress
assignee: nobody → dann frazier (dannf)
Changed in linux (Ubuntu Disco):
status: New → In Progress
assignee: nobody → dann frazier (dannf)
Seth Forshee (sforshee) on 2019-08-30
Changed in linux (Ubuntu):
status: In Progress → Fix Committed
Changed in linux (Ubuntu Disco):
status: In Progress → Fix Committed

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

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 for documentation how to enable and use -proposed. Thank you!

tags: added: verification-needed-disco
dann frazier (dannf) wrote :

Verification by smoke test for regressions:

ubuntu@scobee:~$ cat /proc/version
Linux version 5.0.0-28-generic (buildd@bos02-arm64-078) (gcc version 8.3.0 (Ubuntu/Linaro 8.3.0-6ubuntu1)) #30-Ubuntu SMP Wed Sep 4 11:48:26 UTC 2019

tags: added: verification-done-disco
removed: verification-needed-disco
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