[lkml]   [2006]   [Mar]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: sis96x compiled in by error: delay of one minute at boot
Hi Jean, Etienne:


> 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 <> [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.)


> > 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.


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.


Mark M. Hoffman

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2006-03-15 04:49    [W:0.058 / U:10.408 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site