• Konstantin Baidarov's avatar
    [MTD] chips cfi_cmdset_0002: Prevent timeout race · b95f9609
    Konstantin Baidarov authored
    We've noticed that sometimes "MTD do_write_buffer(): software timeout"
    message was printed out when writing to a Fujitsu NOR flash.
    It turned out that this was because of a race in the timeout handling
    do_write_buffer(). A small timeout of (HZ / 1000) + 1 is used there, and
    sometimes if the timer interrupt handling takes more than one or even two
    jiffies (which is 1-2 ms with HZ == 1000) and that interrupt happens just
    after chip_ready() call, the driver bails out from a ready polling loop
    despite the chip has actually become ready while all those interrupts were
    handled. To deal with this issue, extra check for chip ready is neccessary on
    timeout expiration (and the checks should better be reordered).
    As do_write_oneword() uses the same approach, it needs to also be changed.
    Signed-off-by: default avatarKonstantin Baidarov <kbaidarov@ru.mvista.com>
    Signed-off-by: default avatarSergei Shtylyov <sshtylyov@ru.mvista.com>
    Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
    b95f9609
cfi_cmdset_0002.c 46.4 KB