On Mon, 2026-01-05 at 14:08 +0000, Daniel Thompson wrote: > On Mon, Jan 05, 2026 at 12:52:14PM +0000, Daniel Thompson wrote: > > Hi Marcos > > > > On Sat, Dec 27, 2025 at 09:16:07AM -0300, Marcos Paulo de Souza > > wrote: > > > The parts 1 and 2 can be found here [1] and here[2]. > > > > > > The changes proposed in this part 3 are mostly to clarify the > > > usage of > > > the interfaces for NBCON, and use the printk helpers more > > > broadly. > > > Besides it, it also introduces a new way to register consoles > > > and drop thes the CON_ENABLED flag. It seems too much, but in > > > reality > > > the changes are not complex, and as the title says, it's > > > basically a > > > cleanup without changing the functional changes. > > > > I ran this patchset through the kgdb test suite and I'm afraid it > > is > > reporting functional changes. > > > > Specifically the earlycon support for kdb has regressed (FWIW the > > problem bisects down to the final patch in the series where > > CON_ENABLED > > is removed). > > > > Reproduction on x86-64 KVM outside of the test suite should be > > easy: > > > > make defconfig > > scripts/config \ > > --enable DEBUG_INFO \ > > --enable DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT \ > > --enable DEBUG_FS \ > > --enable KALLSYMS_ALL \ > > --enable MAGIC_SYSRQ \ > > --enable KGDB \ > > --enable KGDB_TESTS \ > > --enable KGDB_KDB \ > > --enable KDB_KEYBOARD \ > > --enable LKDTM \ > > --enable SECURITY_LOCKDOWN_LSM > > make olddefconfig > > make -j$(nproc) > > qemu-system-x86_64 \ > > -m 1G -smp 2 -nographic \ > > -kernel arch/x86/boot/bzImage \ > > -append "console=ttyS0,115200 kgdboc=ttyS0 > > earlycon=uart8250,io,0x3f8 kgdboc_earlycon kgdbwait" > > Actually I realized there was a simpler reproduction (hinted at by > the > missing "printk: legacy bootconsole [uart8250] enabled" in the > regressed > case). It looks like the earlycon simply doesn't work and that means > the > reproduction doesn't require anything related to kgdb at all. Simply: > > make defconfig > make -j$(nproc) > qemu-system-x86_64 -m 1G -smp 2 -nographic -kernel > arch/x86/boot/bzImage \ > -append "earlycon=uart8250,io,0x3f8" > > With the part 3 patchset applied I get no output from the earlycon > (without the patch set I get the early boot messages which, as > expected, > stop when tty0 comes up).
Hi Daniel, sorry for the late reply! Lots of things to check lately :) Ok, I reproduced here, thanks a lot for testing kgdboc, it's a quick way to check that the new register_console_force is not working. Let me take a look to find what's wrong. Thanks a lot for finding this issue! > > > Daniel.
