Hi Wander, Not sure if this has been reported before but since last few weeks I am seeing a problem with the rpi4 serial port on my test setup. The initial boot message will be completely garbled as you can see at: https://lava.qa.codethink.co.uk/scheduler/job/543#L380. The last good boot was https://lava.qa.codethink.co.uk/scheduler/job/540#L390. The bisect log: # bad: [455e73a07f6e288b0061dfcf4fcf54fa9fe06458] Merge tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux # good: [7e7b69654724c72bd3219b71f58937845dca0b2b] Merge tag 'dma-mapping-5.17' of git://git.infradead.org/users/hch/dma-mapping git bisect start '455e73a07f6e288b0061dfcf4fcf54fa9fe06458' '7e7b69654724c72bd3219b71f58937845dca0b2b' # bad: [342465f5337f7bd5b8bd3b6f939ac12b620cbb43] Merge tag 'tty-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty git bisect bad 342465f5337f7bd5b8bd3b6f939ac12b620cbb43 # good: [6dc69d3d0d18d587ab9d809fe060ba4417cf0279] Merge tag 'driver-core-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core git bisect good 6dc69d3d0d18d587ab9d809fe060ba4417cf0279 # good: [e269f7acdc53623769da31135f60afeb3a65eaff] staging: r8188eu: remove the private ioctl "wps_assoc_req_ie" git bisect good e269f7acdc53623769da31135f60afeb3a65eaff # bad: [ad234e2bac274a43c9fa540bde8cd9f0c627b71f] tty: serial: meson: Drop the legacy compatible strings and clock code git bisect bad ad234e2bac274a43c9fa540bde8cd9f0c627b71f # good: [c66453ce8af8bac78a72ba4e21fd9a86720127d7] tty: fix kernel-doc in n_tty.c git bisect good c66453ce8af8bac78a72ba4e21fd9a86720127d7 # good: [0882b473b084df31288003b3bee974aabac9dcf9] tty: serial: samsung: Enable console as module git bisect good 0882b473b084df31288003b3bee974aabac9dcf9 # bad: [b4a29b94804c4774f22555651296b838df6ec0e4] serial: 8250: Move Alpha-specific quirk out of the core git bisect bad b4a29b94804c4774f22555651296b838df6ec0e4 # good: [e822b4973f49015e1c6f63b91c8641ed9bfaf229] tty/ldsem: Fix syntax errors in comments git bisect good e822b4973f49015e1c6f63b91c8641ed9bfaf229 # good: [fb09d0ac07725b442b32dbf53f0ab0bea54804e9] tty: Fix the keyboard led light display problem git bisect good fb09d0ac07725b442b32dbf53f0ab0bea54804e9 # bad: [5021d709b31b8a14317998a33cbc78be0de9ab30] tty: serial: Use fifo in 8250 console driver git bisect bad 5021d709b31b8a14317998a33cbc78be0de9ab30 # good: [adbfddc757aec1ed54ccb35c4a7ca9170df827e0] docs/driver-api: Replace a comma in the n_gsm.rst with a double colon git bisect good adbfddc757aec1ed54ccb35c4a7ca9170df827e0 # first bad commit: [5021d709b31b8a14317998a33cbc78be0de9ab30] tty: serial: Use fifo in 8250 console driver And, indeed reverting 5021d709b31b ("tty: serial: Use fifo in 8250 console driver") on top of 23a46422c561 ("Merge tag 'net-5.17-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net") fixes the problem for me. This is seen on every boot and I will be happy to test any patch. -- Regards Sudip
