| Message ID | 20220428062430.31010-5-paul.gortmaker@windriver.com |
|---|---|
| State | New |
| Headers | show |
| Series | platform: allow ATOM PMC code to be optional | expand |
Hi, On 4/28/22 08:24, Paul Gortmaker wrote: > This caught my eye when I saw it was def_bool and hence largely > pointless to have a Kconfig for it at all. > > Yet there is no reason why you shouldn't be able to opt out of Atom > platform support if you only care about desktop and server class CPUs. > > It was introduced as def_bool, but there is no obvious reason as to why > it was forcibly built-in for everyone, other than LPSS implicitly > relying on it (which is now fixed). So here we fix up the Kconfig and > open the door for people to opt out. > > Since putting "default y" on anything that isn't absolutely essential is > generally frowned upon, I made the default be CONFIG_MATOM. People who > use "make oldconfig" or similar won't notice any difference. > > The two "unchanged" lines for PCI and COMMON_CLK appear in the diff from > fixing a whitespace issue that somehow managed to live on despite being > moved between two different Kconfig files since its introduction. > > Cc: Aubrey Li <aubrey.li@linux.intel.com> > Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > Cc: Hans de Goede <hdegoede@redhat.com> > Cc: Mark Gross <markgross@kernel.org> > Cc: platform-driver-x86@vger.kernel.org > Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> > --- > drivers/platform/x86/Kconfig | 11 ++++++++--- > 1 file changed, 8 insertions(+), 3 deletions(-) > > diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig > index f08ad85683cb..86459e99d831 100644 > --- a/drivers/platform/x86/Kconfig > +++ b/drivers/platform/x86/Kconfig > @@ -1163,6 +1163,11 @@ config WINMATE_FM07_KEYS > endif # X86_PLATFORM_DEVICES > > config PMC_ATOM > - def_bool y > - depends on PCI > - select COMMON_CLK > + bool "Intel Atom SOC Power Management Controller driver" > + default MATOM Besides the remarks from Andy, this does seem like a weird default, MATOM means that gcc is passed -march=atom nothing more and nothing less. For a distro kernel which may e.g. set CONFIG_GENERIC_CPU we still want this enabled. But as said it is brought in by CONFIG_X86_INTEL_LPSS when that is set. Thinking more about this I think it might be best to just do this instead, replacing patch 2 + 4 of this set: diff --git a/drivers/clk/x86/Makefile b/drivers/clk/x86/Makefile index 1244c4e568ff..c2088b3c4081 100644 --- a/drivers/clk/x86/Makefile +++ b/drivers/clk/x86/Makefile @@ -1,6 +1,4 @@ # SPDX-License-Identifier: GPL-2.0-only -obj-$(CONFIG_PMC_ATOM) += clk-pmc-atom.o obj-$(CONFIG_X86_AMD_PLATFORM_DEVICE) += clk-fch.o -clk-x86-lpss-y := clk-lpss-atom.o -obj-$(CONFIG_X86_INTEL_LPSS) += clk-x86-lpss.o +obj-$(CONFIG_X86_INTEL_LPSS) += clk-lpss-atom.o clk-pmc-atom.o obj-$(CONFIG_CLK_LGM_CGU) += clk-cgu.o clk-cgu-pll.o clk-lgm.o diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig index f08ad85683cb..85c396a43048 100644 --- a/drivers/platform/x86/Kconfig +++ b/drivers/platform/x86/Kconfig @@ -1161,8 +1161,3 @@ config WINMATE_FM07_KEYS that delivers key events when these buttons are pressed. endif # X86_PLATFORM_DEVICES - -config PMC_ATOM - def_bool y - depends on PCI - select COMMON_CLK diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile index 4a59f47a46e2..cc2a74713313 100644 --- a/drivers/platform/x86/Makefile +++ b/drivers/platform/x86/Makefile @@ -126,7 +126,7 @@ obj-$(CONFIG_INTEL_SCU_PCI) += intel_scu_pcidrv.o obj-$(CONFIG_INTEL_SCU_PLATFORM) += intel_scu_pltdrv.o obj-$(CONFIG_INTEL_SCU_WDT) += intel_scu_wdt.o obj-$(CONFIG_INTEL_SCU_IPC_UTIL) += intel_scu_ipcutil.o -obj-$(CONFIG_PMC_ATOM) += pmc_atom.o +obj-$(CONFIG_X86_INTEL_LPSS) += pmc_atom.o # Siemens Simatic Industrial PCs obj-$(CONFIG_SIEMENS_SIMATIC_IPC) += simatic-ipc.o This just folds the enabling of the pmc_atom code into the same Kconfig option as the one used the the LPSS code, so this actually simplify things; while at the same time making it possible to not build the pmc_atom code by unselecting the CONFIG_X86_INTEL_LPSS option. Regards, Hans
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig index f08ad85683cb..86459e99d831 100644 --- a/drivers/platform/x86/Kconfig +++ b/drivers/platform/x86/Kconfig @@ -1163,6 +1163,11 @@ config WINMATE_FM07_KEYS endif # X86_PLATFORM_DEVICES config PMC_ATOM - def_bool y - depends on PCI - select COMMON_CLK + bool "Intel Atom SOC Power Management Controller driver" + default MATOM + depends on PCI + select COMMON_CLK + help + This enables support for the Atom SOC Power Management Controller + driver, and associated platform clocks. If you intend to boot this + kernel on platforms with an intel Atom CPU, say Y here.
This caught my eye when I saw it was def_bool and hence largely pointless to have a Kconfig for it at all. Yet there is no reason why you shouldn't be able to opt out of Atom platform support if you only care about desktop and server class CPUs. It was introduced as def_bool, but there is no obvious reason as to why it was forcibly built-in for everyone, other than LPSS implicitly relying on it (which is now fixed). So here we fix up the Kconfig and open the door for people to opt out. Since putting "default y" on anything that isn't absolutely essential is generally frowned upon, I made the default be CONFIG_MATOM. People who use "make oldconfig" or similar won't notice any difference. The two "unchanged" lines for PCI and COMMON_CLK appear in the diff from fixing a whitespace issue that somehow managed to live on despite being moved between two different Kconfig files since its introduction. Cc: Aubrey Li <aubrey.li@linux.intel.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Mark Gross <markgross@kernel.org> Cc: platform-driver-x86@vger.kernel.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> --- drivers/platform/x86/Kconfig | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)