| Message ID | 20201023033506.GC83870@mattapan.m5p.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | xen/arm: ACPI: Remove EXPERT dependancy, default on for ARM64 | expand |
On 23.10.2020 05:35, Elliott Mitchell wrote: > --- a/xen/arch/arm/Kconfig > +++ b/xen/arch/arm/Kconfig > @@ -32,13 +32,18 @@ menu "Architecture Features" > source "arch/Kconfig" > > config ACPI > - bool "ACPI (Advanced Configuration and Power Interface) Support" if EXPERT > + bool "ACPI (Advanced Configuration and Power Interface) Support" > depends on ARM_64 > + default y if ARM_64 The "if" is pointless with the "depends on". > --- a/xen/arch/arm/acpi/boot.c > +++ b/xen/arch/arm/acpi/boot.c > @@ -254,6 +254,15 @@ int __init acpi_boot_table_init(void) > dt_scan_depth1_nodes, NULL) ) > goto disable; > > + printk("\n" > +"*************************************************************************\n" > +"* WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING *\n" > +"* *\n" > +"* Xen-ARM ACPI support is EXPERIMENTAL. It is presently (October 2020) *\n" > +"* recommended you boot your system in device-tree mode if you can. *\n" > +"*************************************************************************\n" > + "\n"); > + We have an abstraction for such warnings, causing them to appear later in the boot process and then consistently all in one place (both increasing, as we believe, the chances of being noticed): warning_add(). There's a delay accompanied with this, so I think you will want to also have a command line option allowing to silence this warning. "acpi=on" or "acpi=force", as available on x86 and (possibly wrongly right now) not documented as x86-specific, may be (re-)usable, i.e. to avoid having to introduce some entirely new option. Also a few formal nits: The subject tag should have been [PATCH v2], there should have been a short revision log outside of the commit message area, and new patch versione would better start their own new threads than being in-reply-to the earlier version's one. Jan
On Thu, 22 Oct 2020, Elliott Mitchell wrote: > Linux requires UEFI support to be enabled on ARM64 devices. While many > ARM64 devices lack ACPI, the writing seems to be on the wall of UEFI/ACPI > potentially taking over. Some common devices may require ACPI table > support to boot. Let's not make guesses on the direction of the industry in a commit message :-) The following would suffice: Some common ARM64 devices require ACPI to boot (no device tree is available). > For devices which can boot in either mode, continue defaulting to > device-tree. Add warnings about using ACPI advising users of present > situation. > > Signed-off-by: Elliott Mitchell <ehem+xen@m5p.com> > --- > Okay, hopefully this is okay. Warning in Kconfig, warning on boot. > Perhaps "default y if ARM_64" is redundant, yet if someone tries to make > it possible to boot aarch32 on a ACPI machine... > > I also want a date in the message. Theory is this won't be there > forever, so a date is essential. > --- > xen/arch/arm/Kconfig | 7 ++++++- > xen/arch/arm/acpi/boot.c | 9 +++++++++ > 2 files changed, 15 insertions(+), 1 deletion(-) > > diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig > index 2777388265..29624d03fa 100644 > --- a/xen/arch/arm/Kconfig > +++ b/xen/arch/arm/Kconfig > @@ -32,13 +32,18 @@ menu "Architecture Features" > source "arch/Kconfig" > > config ACPI > - bool "ACPI (Advanced Configuration and Power Interface) Support" if EXPERT > + bool "ACPI (Advanced Configuration and Power Interface) Support" > depends on ARM_64 > + default y if ARM_64 I am not so sure about the "default y" for the reason that the option is not technically "supported", so it is probably best to take the default line out. Otherwise we end up with a default "unsupported" kconfig which is not great. > ---help--- > > Advanced Configuration and Power Interface (ACPI) support for Xen is > an alternative to device tree on ARM64. > > + Note this is presently EXPERIMENTAL. If a given device has both > + device-tree and ACPI support, it is presently (October 2020) > + recommended to boot using the device-tree. Please remove the date from the message. We'll update as needed in the future. The following works: Note this is presently EXPERIMENTAL. If a given device has both device-tree and ACPI support, it is recommended to boot using the device-tree. > config GICV3 > bool "GICv3 driver" > depends on ARM_64 && !NEW_VGIC > diff --git a/xen/arch/arm/acpi/boot.c b/xen/arch/arm/acpi/boot.c > index 30e4bd1bc5..c0e8f85325 100644 > --- a/xen/arch/arm/acpi/boot.c > +++ b/xen/arch/arm/acpi/boot.c > @@ -254,6 +254,15 @@ int __init acpi_boot_table_init(void) > dt_scan_depth1_nodes, NULL) ) > goto disable; > > + printk("\n" > +"*************************************************************************\n" > +"* WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING *\n" > +"* *\n" > +"* Xen-ARM ACPI support is EXPERIMENTAL. It is presently (October 2020) *\n" > +"* recommended you boot your system in device-tree mode if you can. *\n" > +"*************************************************************************\n" > + "\n"); Please use warning_add and remove the date from the message. > /* > * ACPI is disabled at this point. Enable it in order to parse > * the ACPI tables. > -- > 2.20.1 > > > -- > (\___(\___(\______ --=> 8-) EHM <=-- ______/)___/)___/) > \BS ( | ehem+sigmsg@m5p.com PGP 87145445 | ) / > \_CS\ | _____ -O #include <stddisclaimer.h> O- _____ | / _/ > 8A19\___\_|_/58D2 7E3D DDF4 7BA6 <-PGP-> 41D1 B375 37D0 8714\_|_/___/5445 > >
diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig index 2777388265..29624d03fa 100644 --- a/xen/arch/arm/Kconfig +++ b/xen/arch/arm/Kconfig @@ -32,13 +32,18 @@ menu "Architecture Features" source "arch/Kconfig" config ACPI - bool "ACPI (Advanced Configuration and Power Interface) Support" if EXPERT + bool "ACPI (Advanced Configuration and Power Interface) Support" depends on ARM_64 + default y if ARM_64 ---help--- Advanced Configuration and Power Interface (ACPI) support for Xen is an alternative to device tree on ARM64. + Note this is presently EXPERIMENTAL. If a given device has both + device-tree and ACPI support, it is presently (October 2020) + recommended to boot using the device-tree. + config GICV3 bool "GICv3 driver" depends on ARM_64 && !NEW_VGIC diff --git a/xen/arch/arm/acpi/boot.c b/xen/arch/arm/acpi/boot.c index 30e4bd1bc5..c0e8f85325 100644 --- a/xen/arch/arm/acpi/boot.c +++ b/xen/arch/arm/acpi/boot.c @@ -254,6 +254,15 @@ int __init acpi_boot_table_init(void) dt_scan_depth1_nodes, NULL) ) goto disable; + printk("\n" +"*************************************************************************\n" +"* WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING *\n" +"* *\n" +"* Xen-ARM ACPI support is EXPERIMENTAL. It is presently (October 2020) *\n" +"* recommended you boot your system in device-tree mode if you can. *\n" +"*************************************************************************\n" + "\n"); + /* * ACPI is disabled at this point. Enable it in order to parse * the ACPI tables.
Linux requires UEFI support to be enabled on ARM64 devices. While many ARM64 devices lack ACPI, the writing seems to be on the wall of UEFI/ACPI potentially taking over. Some common devices may require ACPI table support to boot. For devices which can boot in either mode, continue defaulting to device-tree. Add warnings about using ACPI advising users of present situation. Signed-off-by: Elliott Mitchell <ehem+xen@m5p.com> --- Okay, hopefully this is okay. Warning in Kconfig, warning on boot. Perhaps "default y if ARM_64" is redundant, yet if someone tries to make it possible to boot aarch32 on a ACPI machine... I also want a date in the message. Theory is this won't be there forever, so a date is essential. --- xen/arch/arm/Kconfig | 7 ++++++- xen/arch/arm/acpi/boot.c | 9 +++++++++ 2 files changed, 15 insertions(+), 1 deletion(-)