Re: [PATCH 2/4] serial: core: fix broken sysrq port unlock

On Tue, Jun 2, 2020 at 5:03 PM Johan Hovold johan@kernel.org wrote:

Commit d6e1935819db ("serial: core: Allow processing sysrq at port unlock time") worked around a circular locking dependency by adding helpers used to defer sysrq processing to when the port lock was released.

A later commit unfortunately converted these inline helpers to exported functions despite the fact that the unlock helper was restoring irq flags, something which needs to be done in the same function that saved them (e.g. on SPARC).

I'm not familiar with sparc, can you elaborate a bit what is ABI / architecture lock implementation background?