[Question] bluetooth/{bnep,cmtp,hidp}: memory barriers

Andrea Parri
2018-07-30T03:10:43Z

Hi,

I'm currently puzzled by the the three calls to smp_mb__before_atomic()
in bnep_session(), cmtp_session() and hidp_session_run() respectively:

On the one hand, these barriers provide no guarantee on the subsequent
atomic_read(s->terminate) (as the comments preceding the barriers seem
to suggest), because atomic_read() is not a read-modify-write.

On the other hand, I'm currently unable to say *why such an "mb" would
be required: not being too familiar with this code, I figured I should
ask before sending a patch. ;-)

Andrea