Messages in this thread | | | Subject | Re: [PATCH] block: paride: on26: Replace mdelay with msleep in on26_test_port | From | Jia-Ju Bai <> | Date | Sat, 27 Jan 2018 12:13:30 +0800 |
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On 2018/1/27 1:31, Al Viro wrote: > On Fri, Jan 26, 2018 at 11:42:25PM +0800, Jia-Ju Bai wrote: >> After checking all possible call chains to on26_test_port() here, >> my tool finds that this function is never called in atomic context, >> namely never in an interrupt handler or holding a spinlock. >> And on26_test_port() is only called by pi_probe_unit() that calls >> wait_event() through pi_claim(), >> so it indicates that on26_test_port() can call functions that can sleep. >> Thus mdelay can be replaced with msleep to avoid busy wait. > Sigh... Here's how I would've written it: > > " > on26_test_port() is never called from atomic contexts. > > It has no direct callers and it is reachable only via ->test_port. > ->test_port has only one user: > drivers/block/paride/paride.c:322: max = pi->proto->test_port(pi); > in pi_probe_unit(). That gets called only from pi_init(), called from > p{d,cd,f,t,g}_detect(), called from module_init stuff, all of the above > without entering atomic contexts along the way. > > Despite never getting called from atomic contexts, on26_test_port() contains > mdelay(100), i.e. busy-loops for 0.1s; that's neither nice nor needed, since > msleep() would serve just as well. > > Found by [reference to tool]"
Okay, thanks for your patient guidance :) I will revise the description and send v2 patch, and follow the advice in my next patches.
Thanks, Jia-Ju Bai
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