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    SubjectRe: usb-serial ipaq kernel problem
    On Tue, 30 May 2006 17:06:27 +0200
    Frank Gevaerts <frank.gevaerts@fks.be> wrote:

    | On Tue, May 30, 2006 at 11:38:01AM -0300, Luiz Fernando N. Capitulino wrote:
    | > On Tue, 30 May 2006 10:21:41 +0200
    | > Frank Gevaerts <frank.gevaerts@fks.be> wrote:
    | >
    | > | On Mon, May 29, 2006 at 07:33:30PM -0300, Luiz Fernando N. Capitulino wrote:
    | > | > On Mon, 29 May 2006 22:47:24 +0200
    | > | > I see.
    | > | >
    | > | > Did you try to just kill the read urb in the ipaq_open's error path?
    | > |
    | > | Yes, that's what I did at first. It works, but with the long waits (we see
    | > | waits up to 80-90 seconds right now) I was afraid that the urb might timeout
    | > | before the control message succeeds.
    | >
    | > Hmmm, I see.
    | >
    | > My only (obvious) question is that if it's really safe to send the read
    | > urb after the control message..
    |
    | Since it is bulk, it is not guaranteed to start before the control
    | message anyway, so it should be safe.
    |
    | The patch looks correct to me, but I would still like to increase
    | KP_RETRIES a bit. If I read the code correctly, the current setup allows
    | for 10 seconds between usb connect and acknowledging the control
    | message. This is enough if the device is only connected when booted
    | (which is the normal use case). However, in our case, we do
    | software-initiated reboots of the ipaq while it is attached to the usb
    | bus, which can take much longer, so for us KP_RETRIES should be at least
    | 1000, maybe 2000. Of course, we can always run a patched kernel for this.

    Hmmm, what do you think about keeping the current default value and
    adding a module parameter to change it?

    | I'll test the patch later today.
    |
    | Anyway, we have not seen the usb_serial_disconnect bug since applying
    | your patch, so that bug is also probably gone (we have had nearly 1000
    | successfull connects/disconnects since then)

    Nice to know.

    --
    Luiz Fernando N. Capitulino
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