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    SubjectRe: sis96x compiled in by error: delay of one minute at boot
    Hi Jean, Etienne:

    <snip>

    > On 2006-03-13, Etienne Lorrain wrote:
    > > Sorry, I was just assuming that while probing I2C hardware one per one,
    > > if one line is diplayed for each driver I do not have - then the kernel
    > > will at least display one line if it found something.

    * Jean Delvare <khali@linux-fr.org> [2006-03-14 10:43:54 +0100]:
    > This is the way it should work, but unfortunately our i2c bus drivers
    > don't follow these rules. Almost all of them keep quiet when loaded
    > (except for i2c-sis96x, as you found out by yourself) but they also keep
    > quiet (unless debug is enabled) when a supported device is found, which
    > is not so good.
    >
    > Mark, can you provide a patch to your i2c-sis96x driver so that it'll
    > keep quiet when no supported device is found?

    Lots of drivers printk messages when they load - IMO it's useful info.
    E.g. how else could Etienne discover that he accidentally built a kernel
    with dozens of i2c bus drivers (and probably all of the hwmon drivers)
    built-in by accident?

    (But, I'll send the trivial patch to lm-sensors list if you still want it.)

    <snip>

    > > Removing the last PCA9564 gives me:
    > > Mar 13 21:46:48 ubuntu kernel: [ 47.699704] input: AT Translated Set 2
    > > keyboard as /class/input/input1
    > > Mar 13 21:46:48 ubuntu kernel: [ 47.702667] input: PC Speaker
    > > as /class/input/input2
    > > Mar 13 21:46:48 ubuntu kernel: [ 47.705445] i2c /dev entries driver
    > > Mar 13 21:46:48 ubuntu kernel: [ 47.708637] i2c-parport: using default
    > > base 0x378
    > > Mar 13 21:46:48 ubuntu kernel: [ 70.366096] hdaps: supported laptop not
    > > found!
    > > Mar 13 21:46:48 ubuntu kernel: [ 70.368750] hdaps: driver init failed
    > > (ret=-6)!
    >
    > You should also drop "Parallel port adapter (light)", it might cause
    > the same kind of delays and probably explains (part of) the 23 second
    > delay remaining.

    <snip>

    Wow, that's a huge delay. One alternative would be for i2c slaves to behave
    more like USB and do the probing asynchronous to driver load; i.e. 'modprobe
    w83627hf' returns before the chip is actually recognized and attached.

    OTOH, that brings up all the related problems. E.g., you could no longer
    expect this simple fragment of a RC script to work...

    modprobe i2c-sis96x
    modprobe asb100
    sensors -s

    Short of fixing all that... one has to accept that (1) i2c bus probing is
    slow, and (2) some i2c busses themselves are not reliably detectable...

    ...thus (3) it's a bad idea to build all of that into your monolithic kernel.

    As Jean suggests, either use modules or build only the drivers for hardware
    you actually have.

    Regards,

    --
    Mark M. Hoffman
    mhoffman@lightlink.com

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