On Tue, 08 Feb 2022 23:26:54 +0530, Ankit Pandey said: > And I was asked to verify if there is some specific meaning is attached to > comment here (which was causing the issue). > I would be glad you could explain me how should I approach this issue? One > way would > be to rewrite that these variables could be defined as volatile (just add a > comment) and then compile driver and see that build goes through without > any error. It turns out that the C keyword 'volatile' usually doesn't actually do what needs to happen if a variable actually *is* volatile and subject to change while the executing thread isn't looking. There's a good documentation file on this: Documentation/process/volatile-considered-harmful.rst But in summary - "If you thought you needed 'volatile' in your code, you probably needed locking primitives instead". > Other way would be that try to understand what this function is supposed to > be doing and then figure out author's intent of putting volatile there. How > should I take decision on these (or if they are wrong approaches) ? Given that struct pwrctlr_priv already contains a mutex_lock, what was probably *intended* was "the variables cpwm, tog, cpwm_tog, and tgt_rpwm are protected by the mutex_lock and may only be changed by the mutex holder, while pwr_mode, smart_ps, and alives are not subject to change on the fly". But actually reading and understanding the code would be required to verify that. _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
