GIT BISECT RESULTS

So, I managed to run the git bisection and ended up having to do it twice: once looking for the first commit that broke audio (turns out a major total breakage occurs before the original diagnosed issue appeared), then to spot the origin of the main issue (I ignored the other form of malfunctioning, marking it as 'good').

---AUDIO BREAKAGE BISECT LOG---

git bisect start
# bad: [53a19a9a5f9811a911e9b69ef36afb0d66b5d85c] s390x/tcg: always enable AFP for linux-user
git bisect bad 53a19a9a5f9811a911e9b69ef36afb0d66b5d85c
# good: [4743c23509a51bd4ee85cc272287a41917d1be35] Update version for v2.12.0 release
git bisect good 4743c23509a51bd4ee85cc272287a41917d1be35
# bad: [7f9ddf64d5fe5bfaa91ae0ec52217d86f4d86452] target/arm: Implement SVE Floating Point Accumulating Reduction Group
git bisect bad 7f9ddf64d5fe5bfaa91ae0ec52217d86f4d86452
# good: [cc9743c236cce8a35449e3ef67140287b68bb705] iscsi: Query and save device designator when opening
git bisect good cc9743c236cce8a35449e3ef67140287b68bb705
# good: [1e05197f24c49d52f339de9053bb1d17082f1be3] translate-all: iterate over TBs in a page with PAGE_FOR_EACH_TB
git bisect good 1e05197f24c49d52f339de9053bb1d17082f1be3
# good: [2aeba0d007d33efa12a6339bb140aa634e0d52eb] target/arm: Strict alignment for ARMv6-M and ARMv8-M Baseline
git bisect good 2aeba0d007d33efa12a6339bb140aa634e0d52eb
# bad: [00928a421d47f49691cace1207481b7aad31b1f1] Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20180626' into staging
git bisect bad 00928a421d47f49691cace1207481b7aad31b1f1
# bad: [35e238c9330669882487f9929e0aa97900431853] Merge remote-tracking branch 'remotes/kraxel/tags/audio-20180625-pull-request' into staging
git bisect bad 35e238c9330669882487f9929e0aa97900431853
# good: [c52e53f429aa562539f5da2e7c21c66c6f9a8a16] Merge remote-tracking branch 'remotes/dgibson/tags/ppc-for-3.0-20180622' into staging
git bisect good c52e53f429aa562539f5da2e7c21c66c6f9a8a16
# good: [be25fcc4d2faeb3ffa8db813272963bae659c4c2] MAINTAINERS: Update QAPI stanza for commit fb0bc835e56
git bisect good be25fcc4d2faeb3ffa8db813272963bae659c4c2
# good: [518d23a976b7dad77cfef3e41c3531ac89229b00] Merge remote-tracking branch 'remotes/ehabkost/tags/python-next-pull-request' into staging
git bisect good 518d23a976b7dad77cfef3e41c3531ac89229b00
# bad: [8ced0669237b2bbedac3e4ce6fcf7aaaafaae663] audio/hda: tweak timer adjust logic
git bisect bad 8ced0669237b2bbedac3e4ce6fcf7aaaafaae663
# bad: [0a373bb310c1533e24aa5e3edbf206507fb342ea] audio/hda: turn some dprintfs into trace points
git bisect bad 0a373bb310c1533e24aa5e3edbf206507fb342ea
# bad: [280c1e1cdb24d80ecdfcdfc679ccc5e8ed7af45d] audio/hda: create millisecond timers that handle IO
git bisect bad 280c1e1cdb24d80ecdfcdfc679ccc5e8ed7af45d
# first bad commit: [280c1e1cdb24d80ecdfcdfc679ccc5e8ed7af45d] audio/hda: create millisecond timers that handle IO

---END---


---ORIGINAL ISSUE BISECT LOG---

git bisect start
# bad: [35e238c9330669882487f9929e0aa97900431853] Merge remote-tracking branch 'remotes/kraxel/tags/audio-20180625-pull-request' into staging
git bisect bad 35e238c9330669882487f9929e0aa97900431853
# good: [c52e53f429aa562539f5da2e7c21c66c6f9a8a16] Merge remote-tracking branch 'remotes/dgibson/tags/ppc-for-3.0-20180622' into staging
git bisect good c52e53f429aa562539f5da2e7c21c66c6f9a8a16
# good: [cc2ae7c9de14efd72c6205825eb7cd980ac09c11] target/arm: Introduce ARM_FEATURE_M_MAIN
git bisect good cc2ae7c9de14efd72c6205825eb7cd980ac09c11
# good: [be25fcc4d2faeb3ffa8db813272963bae659c4c2] MAINTAINERS: Update QAPI stanza for commit fb0bc835e56
git bisect good be25fcc4d2faeb3ffa8db813272963bae659c4c2
# good: [518d23a976b7dad77cfef3e41c3531ac89229b00] Merge remote-tracking branch 'remotes/ehabkost/tags/python-next-pull-request' into staging
git bisect good 518d23a976b7dad77cfef3e41c3531ac89229b00
# good: [8ced0669237b2bbedac3e4ce6fcf7aaaafaae663] audio/hda: tweak timer adjust logic
git bisect good 8ced0669237b2bbedac3e4ce6fcf7aaaafaae663
# bad: [bc753dc09ff33d99bc9004d7286c50de1d5bece6] audio/hda: enable new timer code by default.
git bisect bad bc753dc09ff33d99bc9004d7286c50de1d5bece6
# good: [4501ee16c76e89e0a2b2beb95f3b93f965997391] audio/hda: detect output buffer overruns
git bisect good 4501ee16c76e89e0a2b2beb95f3b93f965997391
# first bad commit: [bc753dc09ff33d99bc9004d7286c50de1d5bece6] audio/hda: enable new timer code by default.

---END---


I'm attaching both of them, just in case someone wants to replay them.

One thing that I'd like to point out is that the thing I called "total breakage" looks extremely similar to what happens when I set a 2.12 machine on a 3.0 QEMU: complete distortion.
Do I have to study it more in order to see if it really produces the same effect?


Anyway, I'm sorry if such a simple matter took this long but, during one of the initial bisections, an accidental misconfiguration in the testing environment completely wasted the guest I was using (permanent Windows startup failure-level of wasted...).
I had to recover a few things and reinstall as many.