Messages in this thread | | | Date | Fri, 26 Jan 2018 17:31:30 +0000 | From | Al Viro <> | Subject | Re: [PATCH] block: paride: on26: Replace mdelay with msleep in on26_test_port |
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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]"
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