Hello Etienne: * Etienne Lorrain <etienne_lorrain at yahoo.fr> [2006-03-29 11:26:28 +0200]: > --- "Mark M. Hoffman" <mhoffman at lightlink.com> wrote: > > > 885c885 > > > < # CONFIG_I2C_PCA_ISA is not set > > > --- > > > > CONFIG_I2C_PCA_ISA=y > > > > This alone is the cause of the delay. (I have confirmed it by running some > > similar .configs here.) You almost certainly don't own this specialized > > piece of hardware. Worse still, that particular driver has no code to detect > > whether or not the hardware is present. I cc'ed the listed driver author > > (Ian) just in case this might be corrected... but I guess there is no way > > to fix it. > > > > So the delay is (1) an I2C bus driver that is not actually present, trying to > > probe for (2) seven different sensors chip drivers that certainly aren't present > > on the nonexistent bus. Timeouts ensue. > > > > So unless Ian knows a better way to detect that bus driver... the best I can > > advise is to *not* build in those drivers for hardware that you do not have. > > OK, I know the I2C protocol, and I can imagine a hardware board which does > not have a way to detect its own presence - or the presence of its own ISA bus. > What I dislike the most is that, after the driver has taken more than 20 > seconds to probe something it did not find, it did not display anything to > say "either there is a hardware problem, or you should disable me". I repeat just once more: the supported method for identifying hwmon/sensors chips is a Perl script called sensors-detect that is distributed with the lm-sensors package. > Are you sure that there isn't any distribution around trying to insert > _all_ the modules to do hardware detection? No, because that is not supported. All of the major distributions package lm-sensors, and AFAIK they all build hwmon/sensors as modules. They don't insert any of them by default. If a distro was silly enough to blindly insert them all... then it would take forever to boot and nobody would use it. > Note that most I2C driver detect abscence of the hardware in a lot less than > a second: most of the I2C system is fine. Feel free to write a patch for drivers/busses/i2c/i2c-pca-isa.c; I don't have that hardware myself. Otherwise, my final advice is: Patient: It hurts when I do this. Doctor: Don't do that. Regards, -- Mark M. Hoffman mhoffman at lightlink.com
