On Monday, August 24, 2015 03:26:13 PM Wolfram Sang wrote:
> On Mon, Aug 24, 2015 at 01:52:02PM +0300, Jarkko Nikula wrote:
> > Commit 70762abb9f89 ("i2c: Use stable dev_name for ACPI enumerated I2C
> > slaves") broke the lm-sensors which relies on I2C hwmon slave devices under
> > /sys/bus/i2c/devices/ to be named as "x-00yz". However if those hwmon
> > devices are ACPI 5 enumerated their name became "i2c-INTABCD:ij" and sysfs
> > code in lm-sensors does not find them anymore:
> >
> > lib/sysfs.c:665:
> > if ((!subsys || !strcmp(subsys, "i2c")) &&
> > sscanf(dev_name, "%hd-%x", &entry.chip.bus.nr,
> > &entry.chip.addr) == 2) {
> >
> > This patch fixes this by reverting back the old device naming in i2c-core
> > but at the same avoids regression to ALSA SoC drivers that depend on stable
> > device binding.
>
> This way we fix some userspace by going back. However, this name change
> was effective for 18 months, so enough time for some other userspace to
> adapt. We would break the latter by reverting.
Right.
Generally, reverts of such things need to be made relatively quickly.
> I tend to create the symlinks to prevent any further breakage. I am open
> for other suggestions, though. This ugly situation has surely happened
> before somewhere somewhen in the kernel :/
It happens on a regular basis.
In this particular case it looks like we need a mechanism to use the old
naming scheme for hwmon and the new one for everything else or something
similar. I'm afraid I am not familiar enough with the i2c core to suggest
anything specific ATM, though.
Thanks,
Rafael
Attachment:
signature.asc
Description: This is a digitally signed message part.
