Hi Heiner,
On Fri, Apr 05, 2024 at 07:57:24AM +0200, Heiner Kallweit wrote:
> On 05.04.2024 02:54, Andi Shyti wrote:
> > Hi Heiner,
> >
> > first of all, thanks for the fast reaction!
> >
> > On Thu, Apr 04, 2024 at 10:09:50PM +0200, Heiner Kallweit wrote:
> >> The original change adds usage of i2c_root_adapter(), which is
> >> implemented in i2c-mux.c. Therefore we can't use the multiplexing
> >> if I2C_I801=y and I2C_MUX=m.
> >
> > What is wrong with select I2C_MUX?
> >
> It would solve the issue, but:
> We would uselessly enable I2C_MUX also if I2C_MUX_GPIO or DMI are disabled.
> W/o them the mux part in i801 is a no-op. The call to i2c_root_adapter()
> is in a conditionally compiled code part, controlled by:
>
> #if IS_ENABLED(CONFIG_I2C_MUX_GPIO) && defined CONFIG_DMI
>
> > And is this covering all the cases?
> >
> yes
>
> > Last thing, how have you tested and reproduced the issue?
> >
> The CI bot report included a link to the kernel config. So it was easy
> to understand the root cause of the issue. I could reproduce it by setting:
> I2C_I801=y
> I2C_MUX=m
> I2C_MUX_GPIO=m
> This config was also used to test the fix.
>
> Underlying reason for the issue is that i801 has a code dependency on i2c_mux,
> but not on i2c_mux_gpio.
Even though it might look trivial, I need to reproduce the issue
first and check the various cases.
Because I'm not at home and, anyway, the report has come late in
the week, I can queue this up in the next week's pull request.
I'm not extremely happy with the new _CONFIG but I understand the
reason behind it.
Thanks,
Andi
> > Thanks,
> > Andi
> >
> Heiner
>
> >> Handling the dependencies in the code would become unnecessarily
> >> complex, therefore create a new config symbol.
> >>
> >> Fixes: 71b494e043d2 ("i2c: i801: Call i2c_register_spd for muxed child segments")
> >> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> >> Closes: https://lore.kernel.org/oe-kbuild-all/202404042206.MjAQC32x-lkp@xxxxxxxxx/
> >> Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
>
