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    SubjectRe: [PATCH] CDROM: replace jiffies busyloop with msleep
    On 05/22/2007 12:25 PM, Thomas Gleixner wrote:

    > From: Ingo Molnar <>
    > The SJCD driver uses a jiffies busy loop. Replace it with msleep.
    > Signed-off-by: Ingo Molnar <>
    > Acked-by: Thomas Gleixner <>

    Okay, that's just waiting for a reset to complete, which seems perfectly
    fine with a sleeping loop like that, but...

    I re-started working on a rewrite of the mitsumi legacy cdrom driver that
    Pekka Enberg and I have been doing this afternoon again and I ran into not
    being able to use sleeping loops there an hour ago!

    The trouble there is that unless you poll the bloody thing like mad too much
    of the Q subchannels passes below you and you need a huge number of retries
    to get anything out of it. I noticed when I started adding audio bits that
    the driver took full seconds to complete some audio requests while the old
    driver was snappy in that regard. When I replaced our sleeping loop with a
    busy-wait same as the original the snappyness returned and moreover, reading
    the TOC from the CD went from something close to a minute to approximately a
    second. Thought that minute was just because I was dealing with an old junk
    1-speed drive...

    Now, as said, this looks to be fine since it's just waiting for a reset to
    complete, but unless you have the hardware to actually test, be careful in

    Or in fact, maybe even decide there's not much point. The current plan is to
    do mitsumi, sony and panasonic and then throw the rest away (that trio is
    special in so far that controllers for them are still available on a lot of
    old ISA soundcards). Or do you actually have the hardware?

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      Last update: 2007-05-23 20:47    [W:0.020 / U:26.288 seconds]
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