Messages in this thread | | | Date | Mon, 7 Mar 2016 13:51:40 -0800 | From | Brian Norris <> | Subject | Re: [PATCH] mtd: nand: check status before reporting timeout |
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On Fri, Mar 04, 2016 at 05:19:23PM -0800, Brian Norris wrote: > In commit b70af9bef49b ("mtd: nand: increase ready wait timeout and > report timeouts"), we increased the likelihood of scheduling during > nand_wait(). This makes us more likely to hit the time_before(...) > condition, since a lot of time may pass before we get scheduled again. > > Now, the loop was already buggy, since we don't check if the NAND is > ready after exiting the loop; we simply print out a timeout warning. Fix > this by doing a final status check before printing a timeout message. > > This isn't actually a critical bug, since the only effect is a false > warning print. But too many prints never hurt anyone, did they? :) > > Side note: perhaps I'm not smart enough, but I'm not sure what the best > policy is for this kind of loop; do we busy loop (i.e., no > cond_resched()) to keep the lowest I/O latency (it's not great if the > resched is delaying Richard's system ~400ms)? Or do we allow > rescheduling, to play nice with the rest of the system (since some > operations can take quite a while)? > > Reported-by: Richard Weinberger <richard@nod.at> > Signed-off-by: Brian Norris <computersforpeace@gmail.com> > Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com> > Reviewed-by: Richard Weinberger <richard@nod.at> > Reviewed-by: Harvey Hunt <harvey.hunt@imgtec.com>
Applied
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