| Message ID | 20240405142823.615609-1-arnd@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | i2c: i801: add I2C_MUX dependency | expand |
On Fri, Apr 05, 2024 at 04:27:43PM +0200, Arnd Bergmann wrote: > From: Arnd Bergmann <arnd@arndb.de> > > When I2C_MUX is a loadable module but I2C_I801 is built-in, the newly > added notifier function causes a link error: > > x86_64-linux-ld: drivers/i2c/busses/i2c-i801.o: in function `i801_notifier_call': > i2c-i801.c:(.text+0x1f5): undefined reference to `i2c_root_adapter' > > This code is only built if I2C_MUX_GPIO is also enabled, so add a > conditional dependency that allows building the driver as before if the > GPIO part is disabled, but otherwise require the linker dependency at > Kconfig level. > > With the added dependency, the driver cannot be selected by a builtin > ITCO_WDT driver when I2C_MUX_GPIO is a loadable module, so remove > the 'select' statement in that driver as well. This was apparently > never needed at compile-time, and the watchdog driver just needs either > the LPC or the I2C drivers, but never both. > > Configurations that rely on the implied 'select' from the watchdog > driver now need to enable all three. > > Fixes: 71b494e043d2 ("i2c: i801: Call i2c_register_spd for muxed child segments") > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > drivers/i2c/busses/Kconfig | 1 + > drivers/watchdog/Kconfig | 2 -- > 2 files changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig > index 1872f1995c77..2619018dd756 100644 > --- a/drivers/i2c/busses/Kconfig > +++ b/drivers/i2c/busses/Kconfig > @@ -108,6 +108,7 @@ config I2C_HIX5HD2 > config I2C_I801 > tristate "Intel 82801 (ICH/PCH)" > depends on PCI > + depends on I2C_MUX || I2C_MUX_GPIO=n > select P2SB if X86 > select CHECK_SIGNATURE if X86 && DMI > select I2C_SMBUS > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index 0b0df3fe1efd..4dfb3773e6e2 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -1301,8 +1301,6 @@ config ITCO_WDT > select WATCHDOG_CORE > depends on I2C || I2C=n > depends on MFD_INTEL_PMC_BXT || !MFD_INTEL_PMC_BXT > - select LPC_ICH if !EXPERT > - select I2C_I801 if !EXPERT && I2C Sorry, I don't understand why LPC_ICH and I2C_I801 are neither a dependency nor need to be selected. What if both LPC_ICH=n and I2C_I801=n, or if one is selected but the other is needed to connect to the watchdog ? Guenter > help > Hardware driver for the intel TCO timer based watchdog devices. > These drivers are included in the Intel 82801 I/O Controller > -- > 2.39.2 >
On Sat, Apr 6, 2024, at 15:08, Guenter Roeck wrote: > On Fri, Apr 05, 2024 at 04:27:43PM +0200, Arnd Bergmann wrote: >> >> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig >> index 1872f1995c77..2619018dd756 100644 >> --- a/drivers/i2c/busses/Kconfig >> +++ b/drivers/i2c/busses/Kconfig >> @@ -108,6 +108,7 @@ config I2C_HIX5HD2 >> config I2C_I801 >> tristate "Intel 82801 (ICH/PCH)" >> depends on PCI >> + depends on I2C_MUX || I2C_MUX_GPIO=n >> select P2SB if X86 >> select CHECK_SIGNATURE if X86 && DMI >> select I2C_SMBUS >> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig >> index 0b0df3fe1efd..4dfb3773e6e2 100644 >> --- a/drivers/watchdog/Kconfig >> +++ b/drivers/watchdog/Kconfig >> @@ -1301,8 +1301,6 @@ config ITCO_WDT >> select WATCHDOG_CORE >> depends on I2C || I2C=n >> depends on MFD_INTEL_PMC_BXT || !MFD_INTEL_PMC_BXT >> - select LPC_ICH if !EXPERT >> - select I2C_I801 if !EXPERT && I2C > > Sorry, I don't understand why LPC_ICH and I2C_I801 are neither a dependency > nor need to be selected. What if both LPC_ICH=n and I2C_I801=n, or if one is > selected but the other is needed to connect to the watchdog ? The Kconfig dependencies are only required if there is a compile-time dependencies. In this case, both LPC_ICH and I2C_I801 create a platform device that is consumed by ITCO_WDT, but it could in theory work with any other such driver providing the device. It would be fine to make this explicit by adding 'depends on LPC_ICH || I2C_I801' to enforce that the watchdog driver can only be selected on if at least one of these is present, but we have a lot of examples where we don't spell out this type of dependency. The two 'select' statements in comparison a really bad idea because a driver should never need to force-enable a user visible symbol in another subsystem, and because no single machine would actually require both the i810 and the ich driver. Arnd
On Sat, Apr 06, 2024 at 05:45:57PM +0200, Arnd Bergmann wrote: > On Sat, Apr 6, 2024, at 15:08, Guenter Roeck wrote: > > On Fri, Apr 05, 2024 at 04:27:43PM +0200, Arnd Bergmann wrote: > >> > >> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig > >> index 1872f1995c77..2619018dd756 100644 > >> --- a/drivers/i2c/busses/Kconfig > >> +++ b/drivers/i2c/busses/Kconfig > >> @@ -108,6 +108,7 @@ config I2C_HIX5HD2 > >> config I2C_I801 > >> tristate "Intel 82801 (ICH/PCH)" > >> depends on PCI > >> + depends on I2C_MUX || I2C_MUX_GPIO=n > >> select P2SB if X86 > >> select CHECK_SIGNATURE if X86 && DMI > >> select I2C_SMBUS > >> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > >> index 0b0df3fe1efd..4dfb3773e6e2 100644 > >> --- a/drivers/watchdog/Kconfig > >> +++ b/drivers/watchdog/Kconfig > >> @@ -1301,8 +1301,6 @@ config ITCO_WDT > >> select WATCHDOG_CORE > >> depends on I2C || I2C=n > >> depends on MFD_INTEL_PMC_BXT || !MFD_INTEL_PMC_BXT > >> - select LPC_ICH if !EXPERT > >> - select I2C_I801 if !EXPERT && I2C > > > > Sorry, I don't understand why LPC_ICH and I2C_I801 are neither a dependency > > nor need to be selected. What if both LPC_ICH=n and I2C_I801=n, or if one is > > selected but the other is needed to connect to the watchdog ? > > The Kconfig dependencies are only required if there is a compile-time > dependencies. In this case, both LPC_ICH and I2C_I801 create a > platform device that is consumed by ITCO_WDT, but it could in > theory work with any other such driver providing the device. > > It would be fine to make this explicit by adding > 'depends on LPC_ICH || I2C_I801' to enforce that the watchdog > driver can only be selected on if at least one of these > is present, but we have a lot of examples where we don't > spell out this type of dependency. > Yes, I know, there are lots of inconsistencies in the kernel and its configuration. That should not be an excuse to making it worse. Guenter
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 1872f1995c77..2619018dd756 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -108,6 +108,7 @@ config I2C_HIX5HD2 config I2C_I801 tristate "Intel 82801 (ICH/PCH)" depends on PCI + depends on I2C_MUX || I2C_MUX_GPIO=n select P2SB if X86 select CHECK_SIGNATURE if X86 && DMI select I2C_SMBUS diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 0b0df3fe1efd..4dfb3773e6e2 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -1301,8 +1301,6 @@ config ITCO_WDT select WATCHDOG_CORE depends on I2C || I2C=n depends on MFD_INTEL_PMC_BXT || !MFD_INTEL_PMC_BXT - select LPC_ICH if !EXPERT - select I2C_I801 if !EXPERT && I2C help Hardware driver for the intel TCO timer based watchdog devices. These drivers are included in the Intel 82801 I/O Controller