Re: [PATCH 6.6 000/684] 6.6.128-rc2 review

[Brett A C Sheffield <bacs@librecast.net>]

# Librecast Test Results (FAIL)

020/020 [ OK ] liblcrq
010/010 [ OK ] libmld
120/120 [ OK ] liblibrecast

CPU/kernel: Linux auntie 6.6.128-rc2-ge6906aa7f5ea #1 SMP PREEMPT_DYNAMIC Mon Mar  2 17:31:27 -00 2026 x86_64 AMD Ryzen 9 9950X 16-Core Processor AuthenticAMD GNU/Linux

Builds, boots and passes network tests.  Fails to poweroff.

Bisects to commit 3ba77c48498f0fa29456e2435d7d49eafc0a279c (upstream 4589712e0111352973131bad975023b25569287c) and affects 6.6.y and 6.12.y. Other kernels are unaffected, including mainline.

$ git bisect log
git bisect start
# status: waiting for both good and bad commits
# bad: [e6906aa7f5ea74831bc56d675e1173abf4d1d5a8] Linux 6.6.128-rc2
git bisect bad e6906aa7f5ea74831bc56d675e1173abf4d1d5a8
# status: waiting for good commit(s), bad commit known
# good: [7a137e9bfa0e1919555d60f9dc0c05a7a5ba75d0] Linux 6.6.127
git bisect good 7a137e9bfa0e1919555d60f9dc0c05a7a5ba75d0
# good: [4f052e01c0df1f3dc9d89125466b3fa8ee4373d6] hfsplus: fix volume corruption issue for generic/498
git bisect good 4f052e01c0df1f3dc9d89125466b3fa8ee4373d6
# bad: [2f93eb27e8efeb0002eba89a82778d569a336279] thermal: int340x: Fix sysfs group leak on DLVR registration failure
git bisect bad 2f93eb27e8efeb0002eba89a82778d569a336279
# bad: [8a4170ff96cdf6899b63a78bc588e96ecf0d6063] wifi: rtw88: 8822b: Avoid WARNING in rtw8822b_config_trx_mode()
git bisect bad 8a4170ff96cdf6899b63a78bc588e96ecf0d6063
# good: [51de6101987dace2f4a6235f5b6bd57dc4487a46] media: dvb-core: dmxdevfilter must always flush bufs
git bisect good 51de6101987dace2f4a6235f5b6bd57dc4487a46
# good: [21129c98b9191dcb1590084871266ab228a8daf1] hyper-v: Mark inner union in hv_kvp_exchg_msg_value as packed
git bisect good 21129c98b9191dcb1590084871266ab228a8daf1
# bad: [73c2788b3f488c6d559abb2a4acce54fc6108530] ASoC: sunxi: sun50i-dmic: Add missing check for devm_regmap_init_mmio
git bisect bad 73c2788b3f488c6d559abb2a4acce54fc6108530
# bad: [059f60a78995ad5f3dea512a1b8d31067f3cce42] drm/atmel-hlcdc: fix use-after-free of drm_crtc_commit after release
git bisect bad 059f60a78995ad5f3dea512a1b8d31067f3cce42
# bad: [3ba77c48498f0fa29456e2435d7d49eafc0a279c] drm/amd/display: Ensure link output is disabled in backend reset for PLL_ON
git bisect bad 3ba77c48498f0fa29456e2435d7d49eafc0a279c
# good: [a7953ccb0261ccb358d15f9d51cd85eb6e7fdbda] virt: vbox: uapi: Mark inner unions in packed structs as packed
git bisect good a7953ccb0261ccb358d15f9d51cd85eb6e7fdbda
# first bad commit: [3ba77c48498f0fa29456e2435d7d49eafc0a279c] drm/amd/display: Ensure link output is disabled in backend reset for PLL_ON

commit 3ba77c48498f0fa29456e2435d7d49eafc0a279c
Author: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Date:   Tue Jan 6 11:11:19 2026 -0500

    drm/amd/display: Ensure link output is disabled in backend reset for PLL_ON

    [ Upstream commit 4589712e0111352973131bad975023b25569287c ]

    [Why]
    We're missing the code to actually disable the link output when we have
    to leave the SYMCLK_ON but the TX remains OFF.

    [How]
    Port the code from DCN401 that detects SYMCLK_ON_TX_OFF and disable
    the link output when the backend is reset.

    Reviewed-by: Ovidiu (Ovi) Bunea <ovidiu.bunea@amd.com>
    Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
    Signed-off-by: Matthew Stewart <matthew.stewart2@amd.com>
    Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
    Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
    Signed-off-by: Sasha Levin <sashal@kernel.org>

 drivers/gpu/drm/amd/display/dc/dcn31/dcn31_hwseq.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)