Re: [i2c] [PATCH] update module-init-tools to support the i2c subsystem

On Mon, 14 Jan 2008, Jean Delvare wrote:

On Mon, 14 Jan 2008 11:57:52 +0100 (CET), Geert Uytterhoeven wrote:

quoted

On Sun, 13 Jan 2008, Jon Smirl wrote:

quoted

I don't know exactly what those modules tables are used for. I just
copied what the other subsystems do. Maybe they are used when you make
an initrd to know which drivers to copy into the image.

Module-init-tools needs those table to create module aliases in the *.ko
files from the MODULE_DEVICE_TABLE(), so udev can load the modules based
on the device IDs when the devices appear in sysfs.

I thought that the module aliases were generated by
scripts/mod/modpost? As a matter of fact, I did not apply Jon's patch

Sorry, you're right. Too early in the morning :-)

to module-init-tools, and "modinfo" shows me module aliases properly
for i2c drivers that call MODULE_DEVICE_TABLE():

I've just looked it up again (I had to do a similar thing for Zorro bus
support).  Module-init-tools (depmod) also creates the modules.*map files,
which are used to map from device IDs to module names. I think these are used
by udev to load the appropriate module when a device with a specific device ID
pops up in sysfs.

$ /sbin/modinfo lm90
filename:       /lib/modules/2.6.24-rc7-git4/kernel/drivers/hwmon/lm90.ko
author:         Jean Delvare [off-list ref]
description:    LM90/ADM1032 driver
license:        GPL
vermagic:       2.6.24-rc7-git4 mod_unload
depends:        hwmon
alias:          i2c:Nlm90*
alias:          i2c:Nadm1032*
alias:          i2c:Nlm99*
alias:          i2c:Nlm86*
alias:          i2c:Nmax6657*
alias:          i2c:Nadt7461*
alias:          i2c:Nmax6680*
$

"modprobe i2c:Nadm1032" loads the lm90 driver as expected.

Yes, it's also still not 100% clear to me when `i2c:Nadm1032' is used, and when
modules.i2cmap would be used...

With kind regards,

Geert Uytterhoeven
Software Architect

Sony Network and Software Technology Center Europe
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