bisecting fixing commit since 37f368d8d09d2190e64cdb1cd73d56e3ad50c3df building syzkaller on 6a81331a1d4c744da9204d02ec88d558f7eea9c9 testing commit 37f368d8d09d2190e64cdb1cd73d56e3ad50c3df with gcc (GCC) 10.2.1 20210217 kernel signature: 3e51e5664ed94257fe7f3006e2481ed0990d74a9042900a2a77c3616180e503f all runs: crashed: WARNING: suspicious RCU usage in __ipv6_dev_mc_dec testing current HEAD 86fe2f8aa14f6b0b76a1ce3897a3ee1433e5203a testing commit 86fe2f8aa14f6b0b76a1ce3897a3ee1433e5203a with gcc (GCC) 10.2.1 20210217 kernel signature: df1a2a2d0a97ae61e740594afbcf070822be4f4f306cd160439c964d4324ce06 all runs: OK # git bisect start 86fe2f8aa14f6b0b76a1ce3897a3ee1433e5203a 37f368d8d09d2190e64cdb1cd73d56e3ad50c3df Bisecting: 7648 revisions left to test after this (roughly 13 steps) [0ff0edb550e256597e505eff308f90d9a0b6677c] Merge tag 'locking-core-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip testing commit 0ff0edb550e256597e505eff308f90d9a0b6677c with gcc (GCC) 10.2.1 20210217 kernel signature: 87cbf40d4f770b8215642553adef501e34fa5ab7c4384ae2bbb51a69fa7aec26 all runs: OK # git bisect bad 0ff0edb550e256597e505eff308f90d9a0b6677c Bisecting: 3807 revisions left to test after this (roughly 12 steps) [37f00ab4a003f371f81e0eae76cf372f06dec780] Merge tag 'arm-drivers-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc testing commit 37f00ab4a003f371f81e0eae76cf372f06dec780 with gcc (GCC) 10.2.1 20210217 kernel signature: 699b5f99bf83acd0bc05233d4ab75fa85a6a5a51797ff490b2b79a99c5eafc61 all runs: OK # git bisect bad 37f00ab4a003f371f81e0eae76cf372f06dec780 Bisecting: 1877 revisions left to test after this (roughly 11 steps) [8e3a3249502d8ff92d73d827fb41dd44c5a16f76] Merge tag 'char-misc-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc testing commit 8e3a3249502d8ff92d73d827fb41dd44c5a16f76 with gcc (GCC) 10.2.1 20210217 kernel signature: 99ca136628664a8a3042c602dfe6b155fbeb70173f26c92d93aa995a712197de all runs: OK # git bisect bad 8e3a3249502d8ff92d73d827fb41dd44c5a16f76 Bisecting: 992 revisions left to test after this (roughly 10 steps) [682b26bd80f96c2e4da3eb6dcec8bf684b79151c] Merge tag 'sched_urgent_for_v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip testing commit 682b26bd80f96c2e4da3eb6dcec8bf684b79151c with gcc (GCC) 10.2.1 20210217 kernel signature: 404245eecd1a123ba07e427b6df036e991b073f311d02ea9222b395c59e8a37d all runs: OK # git bisect bad 682b26bd80f96c2e4da3eb6dcec8bf684b79151c Bisecting: 511 revisions left to test after this (roughly 9 steps) [3b9784350f990d8fe2ca08978dc25cd5180d5c21] Merge tag 'io_uring-5.12-2021-04-09' of git://git.kernel.dk/linux-block testing commit 3b9784350f990d8fe2ca08978dc25cd5180d5c21 with gcc (GCC) 10.2.1 20210217 kernel signature: 7b5b65ded94ef4ea2052e58a7f413ed2a90d7a69de17228e34ba2b9e19142e74 all runs: OK # git bisect bad 3b9784350f990d8fe2ca08978dc25cd5180d5c21 Bisecting: 232 revisions left to test after this (roughly 8 steps) [6905b1dc3c32a094f0da61bd656a740f0a97d592] Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm testing commit 6905b1dc3c32a094f0da61bd656a740f0a97d592 with gcc (GCC) 10.2.1 20210217 kernel signature: 6f508f199a6f93538a29659fd9face15eb30b75c758511601c92d9afc7f0acc3 all runs: OK # git bisect bad 6905b1dc3c32a094f0da61bd656a740f0a97d592 Bisecting: 115 revisions left to test after this (roughly 7 steps) [b44d1ddcf835b39a8dc14276d770074deaed297c] Merge tag 'io_uring-5.12-2021-03-27' of git://git.kernel.dk/linux-block testing commit b44d1ddcf835b39a8dc14276d770074deaed297c with gcc (GCC) 10.2.1 20210217 kernel signature: bfad5d9e7464217fc4665a6a5f3292f4c17c28f073b9f3a295415b4437731aeb all runs: OK # git bisect bad b44d1ddcf835b39a8dc14276d770074deaed297c Bisecting: 72 revisions left to test after this (roughly 6 steps) [6c20f6df61ee7b8b562143504cf3e89ae802de87] Merge tag 'for-linus-5.12b-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip testing commit 6c20f6df61ee7b8b562143504cf3e89ae802de87 with gcc (GCC) 10.2.1 20210217 kernel signature: f43ac20bd08e412baf9d34bab7baadfe881a58250e6dee5cfe653c4045c8cdfb all runs: OK # git bisect bad 6c20f6df61ee7b8b562143504cf3e89ae802de87 Bisecting: 29 revisions left to test after this (roughly 5 steps) [4e8d123fca536d1b55f5f9927ad9ee5a444ac41b] Merge tag 'amd-drm-fixes-5.12-2021-03-24' of https://gitlab.freedesktop.org/agd5f/linux into drm-fixes testing commit 4e8d123fca536d1b55f5f9927ad9ee5a444ac41b with gcc (GCC) 10.2.1 20210217 kernel signature: 0df4b58a230cd8cec5fdcac9f400ddd8d52f46f3d913b737f0dc93d3d5d64c79 all runs: OK # git bisect bad 4e8d123fca536d1b55f5f9927ad9ee5a444ac41b Bisecting: 14 revisions left to test after this (roughly 4 steps) [815404281e5df8c684a93eeaede88de262a37023] Merge branch 'linux-5.12' of git://github.com/skeggsb/linux into drm-fixes testing commit 815404281e5df8c684a93eeaede88de262a37023 with gcc (GCC) 10.2.1 20210217 kernel signature: 0df4b58a230cd8cec5fdcac9f400ddd8d52f46f3d913b737f0dc93d3d5d64c79 all runs: OK # git bisect bad 815404281e5df8c684a93eeaede88de262a37023 Bisecting: 7 revisions left to test after this (roughly 3 steps) [8840e3bd981f128846b01c12d3966d115e8617c9] drm/i915: Fix the GT fence revocation runtime PM logic testing commit 8840e3bd981f128846b01c12d3966d115e8617c9 with gcc (GCC) 10.2.1 20210217 kernel signature: 0df4b58a230cd8cec5fdcac9f400ddd8d52f46f3d913b737f0dc93d3d5d64c79 all runs: OK # git bisect bad 8840e3bd981f128846b01c12d3966d115e8617c9 Bisecting: 2 revisions left to test after this (roughly 2 steps) [ab03631087f5c296030dd86265ea02dcdacc6802] drm/i915: Disable LTTPR support when the LTTPR rev < 1.4 testing commit ab03631087f5c296030dd86265ea02dcdacc6802 with gcc (GCC) 10.2.1 20210217 kernel signature: 0df4b58a230cd8cec5fdcac9f400ddd8d52f46f3d913b737f0dc93d3d5d64c79 all runs: OK # git bisect bad ab03631087f5c296030dd86265ea02dcdacc6802 Bisecting: 0 revisions left to test after this (roughly 1 step) [7dffbdedb96a076843719d4ea5b2cd666481c416] drm/i915: Disable LTTPR support when the DPCD rev < 1.4 testing commit 7dffbdedb96a076843719d4ea5b2cd666481c416 with gcc (GCC) 10.2.1 20210217 kernel signature: 0df4b58a230cd8cec5fdcac9f400ddd8d52f46f3d913b737f0dc93d3d5d64c79 all runs: OK # git bisect bad 7dffbdedb96a076843719d4ea5b2cd666481c416 Bisecting: 0 revisions left to test after this (roughly 0 steps) [3f3a9bc1f6df5a1a9ec39e3a5bee420328811be4] drm/i915/ilk-glk: Fix link training on links with LTTPRs testing commit 3f3a9bc1f6df5a1a9ec39e3a5bee420328811be4 with gcc (GCC) 10.2.1 20210217 kernel signature: 0df4b58a230cd8cec5fdcac9f400ddd8d52f46f3d913b737f0dc93d3d5d64c79 all runs: OK # git bisect bad 3f3a9bc1f6df5a1a9ec39e3a5bee420328811be4 3f3a9bc1f6df5a1a9ec39e3a5bee420328811be4 is the first bad commit commit 3f3a9bc1f6df5a1a9ec39e3a5bee420328811be4 Author: Imre Deak Date: Wed Mar 17 20:48:59 2021 +0200 drm/i915/ilk-glk: Fix link training on links with LTTPRs The spec requires to use at least 3.2ms for the AUX timeout period if there are LT-tunable PHY Repeaters on the link (2.11.2). An upcoming spec update makes this more specific, by requiring a 3.2ms minimum timeout period for the LTTPR detection reading the 0xF0000-0xF0007 range (3.6.5.1). Accordingly disable LTTPR detection until GLK, where the maximum timeout we can set is only 1.6ms. Link training in the non-transparent mode is known to fail at least on some SKL systems with a WD19 dock on the link, which exposes an LTTPR (see the References below). While this could have different reasons besides the too short AUX timeout used, not detecting LTTPRs (and so not using the non-transparent LT mode) fixes link training on these systems. While at it add a code comment about the platform specific maximum timeout values. v2: Add a comment about the g4x maximum timeout as well. (Ville) Reported-by: Takashi Iwai Reported-and-tested-by: Santiago Zarate Reported-and-tested-by: Bodo Graumann References: https://gitlab.freedesktop.org/drm/intel/-/issues/3166 Fixes: b30edfd8d0b4 ("drm/i915: Switch to LTTPR non-transparent mode link training") Cc: # v5.11 Cc: Takashi Iwai Cc: Ville Syrjälä Signed-off-by: Imre Deak Reviewed-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20210317184901.4029798-2-imre.deak@intel.com (cherry picked from commit 984982f3ef7b240cd24c2feb2762d81d9d8da3c2) Signed-off-by: Rodrigo Vivi drivers/gpu/drm/i915/display/intel_dp_aux.c | 7 +++++++ drivers/gpu/drm/i915/display/intel_dp_link_training.c | 15 ++++++++++++--- 2 files changed, 19 insertions(+), 3 deletions(-) parent commit 0d02ec6b3136c73c09e7859f0d0e4e2c4c07b49b wasn't tested testing commit 0d02ec6b3136c73c09e7859f0d0e4e2c4c07b49b with gcc (GCC) 10.2.1 20210217 kernel signature: 0df4b58a230cd8cec5fdcac9f400ddd8d52f46f3d913b737f0dc93d3d5d64c79 culprit signature: 0df4b58a230cd8cec5fdcac9f400ddd8d52f46f3d913b737f0dc93d3d5d64c79 parent signature: 0df4b58a230cd8cec5fdcac9f400ddd8d52f46f3d913b737f0dc93d3d5d64c79 revisions tested: 16, total time: 4h52m19.52577317s (build: 1h53m15.450192537s, test: 2h57m1.176566429s) first good commit: 3f3a9bc1f6df5a1a9ec39e3a5bee420328811be4 drm/i915/ilk-glk: Fix link training on links with LTTPRs recipients (to): ["imre.deak@intel.com" "mail@bodograumann.de" "rodrigo.vivi@intel.com" "santiago.zarate@suse.com" "ville.syrjala@linux.intel.com"] recipients (cc): []