• Brian Norris's avatar
    mtd: nand: check status before reporting timeout · 9ebfdf5b
    Brian Norris authored
    In commit b70af9be ("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: default avatarRichard Weinberger <richard@nod.at>
    Signed-off-by: default avatarBrian Norris <computersforpeace@gmail.com>
    Reviewed-by: default avatarBoris Brezillon <boris.brezillon@free-electrons.com>
    Reviewed-by: default avatarRichard Weinberger <richard@nod.at>
    Reviewed-by: default avatarHarvey Hunt <harvey.hunt@imgtec.com>
    9ebfdf5b
nand_base.c 118 KB