Re: [PATCH v4 06/13] ARM64 / ACPI: Introduce early_param for "acpi"
On Fri, Jun 27, 2014 at 11:07:48AM +0200, Arnd Bergmann wrote:
> On Friday 27 June 2014 11:49:29 Hanjun Guo wrote:
> > +
> > +static int __init parse_acpi(char *arg)
> > +{
> > + if (!arg)
> > + return -EINVAL;
> > +
> > + /* "acpi=off" disables both ACPI table parsing and interpreter */
> > + if (strcmp(arg, "off") == 0) {
> > + disable_acpi();
> > + }
> > + /* acpi=strict disables out-of-spec workarounds */
> > + else if (strcmp(arg, "strict") == 0) {
> > + acpi_strict = 1;
> > + } else {
> > + /* Core will printk when we return error */
> > + return -EINVAL;
> > + }
> > +
> > + return 0;
> > +}
> > +early_param("acpi", parse_acpi);
>
> Can you explain in the changelog what happens for the acpi=off case? Does this
> mean we fall back to using data from the dtb instead, or will it just not
> work?
>
> If I understand correctly, this option makes sense on PC systems that will
> still be able to boot using the legacy BIOS services and implicit assumptions
> about the hardware, but that never works on arm64.
>
Yes the way ACPI has been integrated on ARM64 in these patches if you
supply acpi=off it will fall back to DTB if supplied by firmware.
Graeme
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Re: [PATCH v4 06/13] ARM64 / ACPI: Introduce early_param for "acpi"
On Friday 27 June 2014 11:49:29 Hanjun Guo wrote:
> +
> +static int __init parse_acpi(char *arg)
> +{
> + if (!arg)
> + return -EINVAL;
> +
> + /* "acpi=off" disables both ACPI table parsing and interpreter */
> + if (strcmp(arg, "off") == 0) {
> + disable_acpi();
> + }
> + /* acpi=strict disables out-of-spec workarounds */
> + else if (strcmp(arg, "strict") == 0) {
> + acpi_strict = 1;
> + } else {
> + /* Core will printk when we return error */
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +early_param("acpi", parse_acpi);
Can you explain in the changelog what happens for the acpi=off case? Does this
mean we fall back to using data from the dtb instead, or will it just not work?
If I understand correctly, this option makes sense on PC systems that will
still be able to boot using the legacy BIOS services and implicit assumptions
about the hardware, but that never works on arm64.
Arnd
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Re: [PATCH v4 06/13] ARM64 / ACPI: Introduce early_param for acpi
On Friday 27 June 2014 11:49:29 Hanjun Guo wrote:
+
+static int __init parse_acpi(char *arg)
+{
+ if (!arg)
+ return -EINVAL;
+
+ /* acpi=off disables both ACPI table parsing and interpreter */
+ if (strcmp(arg, off) == 0) {
+ disable_acpi();
+ }
+ /* acpi=strict disables out-of-spec workarounds */
+ else if (strcmp(arg, strict) == 0) {
+ acpi_strict = 1;
+ } else {
+ /* Core will printk when we return error */
+ return -EINVAL;
+ }
+
+ return 0;
+}
+early_param(acpi, parse_acpi);
Can you explain in the changelog what happens for the acpi=off case? Does this
mean we fall back to using data from the dtb instead, or will it just not work?
If I understand correctly, this option makes sense on PC systems that will
still be able to boot using the legacy BIOS services and implicit assumptions
about the hardware, but that never works on arm64.
Arnd
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
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Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v4 06/13] ARM64 / ACPI: Introduce early_param for acpi
On Fri, Jun 27, 2014 at 11:07:48AM +0200, Arnd Bergmann wrote:
On Friday 27 June 2014 11:49:29 Hanjun Guo wrote:
+
+static int __init parse_acpi(char *arg)
+{
+ if (!arg)
+ return -EINVAL;
+
+ /* acpi=off disables both ACPI table parsing and interpreter */
+ if (strcmp(arg, off) == 0) {
+ disable_acpi();
+ }
+ /* acpi=strict disables out-of-spec workarounds */
+ else if (strcmp(arg, strict) == 0) {
+ acpi_strict = 1;
+ } else {
+ /* Core will printk when we return error */
+ return -EINVAL;
+ }
+
+ return 0;
+}
+early_param(acpi, parse_acpi);
Can you explain in the changelog what happens for the acpi=off case? Does this
mean we fall back to using data from the dtb instead, or will it just not
work?
If I understand correctly, this option makes sense on PC systems that will
still be able to boot using the legacy BIOS services and implicit assumptions
about the hardware, but that never works on arm64.
Yes the way ACPI has been integrated on ARM64 in these patches if you
supply acpi=off it will fall back to DTB if supplied by firmware.
Graeme
--
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the body of a message to majord...@vger.kernel.org
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Please read the FAQ at http://www.tux.org/lkml/
[PATCH v4 06/13] ARM64 / ACPI: Introduce early_param for "acpi"
From: Al Stone
Introduce two early parameters for "acpi", one is the parameter
to disable ACPI on ARM64 and another one is acpi=strict to disable
out-of-spec workarounds.
Reviewed-by: Grant Likely
Signed-off-by: Al Stone
Signed-off-by: Graeme Gregory
Signed-off-by: Hanjun Guo
---
Documentation/kernel-parameters.txt |3 ++-
drivers/acpi/plat/arm-core.c| 21 +
2 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/Documentation/kernel-parameters.txt
b/Documentation/kernel-parameters.txt
index 8849049..b7e9fc0 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -165,7 +165,7 @@ multipliers 'Kilo', 'Mega', and 'Giga', equalling 2^10,
2^20, and 2^30
bytes respectively. Such letter suffixes can also be entirely omitted.
- acpi= [HW,ACPI,X86]
+ acpi= [HW,ACPI,X86,ARM]
Advanced Configuration and Power Interface
Format: { force | off | strict | noirq | rsdt }
force -- enable ACPI if default was off
@@ -175,6 +175,7 @@ bytes respectively. Such letter suffixes can also be
entirely omitted.
strictly ACPI specification compliant.
rsdt -- prefer RSDT over (default) XSDT
copy_dsdt -- copy DSDT to memory
+ For ARM64, ONLY "off" and "strict" are available.
See also Documentation/power/runtime_pm.txt, pci=noacpi
diff --git a/drivers/acpi/plat/arm-core.c b/drivers/acpi/plat/arm-core.c
index c6c7e03..cf46c25 100644
--- a/drivers/acpi/plat/arm-core.c
+++ b/drivers/acpi/plat/arm-core.c
@@ -108,3 +108,24 @@ void __init acpi_boot_table_init(void)
return;
}
}
+
+static int __init parse_acpi(char *arg)
+{
+ if (!arg)
+ return -EINVAL;
+
+ /* "acpi=off" disables both ACPI table parsing and interpreter */
+ if (strcmp(arg, "off") == 0) {
+ disable_acpi();
+ }
+ /* acpi=strict disables out-of-spec workarounds */
+ else if (strcmp(arg, "strict") == 0) {
+ acpi_strict = 1;
+ } else {
+ /* Core will printk when we return error */
+ return -EINVAL;
+ }
+
+ return 0;
+}
+early_param("acpi", parse_acpi);
--
1.7.9.5
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[PATCH v4 06/13] ARM64 / ACPI: Introduce early_param for acpi
From: Al Stone al.st...@linaro.org
Introduce two early parameters for acpi, one is the parameter
to disable ACPI on ARM64 and another one is acpi=strict to disable
out-of-spec workarounds.
Reviewed-by: Grant Likely grant.lik...@linaro.org
Signed-off-by: Al Stone al.st...@linaro.org
Signed-off-by: Graeme Gregory graeme.greg...@linaro.org
Signed-off-by: Hanjun Guo hanjun@linaro.org
---
Documentation/kernel-parameters.txt |3 ++-
drivers/acpi/plat/arm-core.c| 21 +
2 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/Documentation/kernel-parameters.txt
b/Documentation/kernel-parameters.txt
index 8849049..b7e9fc0 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -165,7 +165,7 @@ multipliers 'Kilo', 'Mega', and 'Giga', equalling 2^10,
2^20, and 2^30
bytes respectively. Such letter suffixes can also be entirely omitted.
- acpi= [HW,ACPI,X86]
+ acpi= [HW,ACPI,X86,ARM]
Advanced Configuration and Power Interface
Format: { force | off | strict | noirq | rsdt }
force -- enable ACPI if default was off
@@ -175,6 +175,7 @@ bytes respectively. Such letter suffixes can also be
entirely omitted.
strictly ACPI specification compliant.
rsdt -- prefer RSDT over (default) XSDT
copy_dsdt -- copy DSDT to memory
+ For ARM64, ONLY off and strict are available.
See also Documentation/power/runtime_pm.txt, pci=noacpi
diff --git a/drivers/acpi/plat/arm-core.c b/drivers/acpi/plat/arm-core.c
index c6c7e03..cf46c25 100644
--- a/drivers/acpi/plat/arm-core.c
+++ b/drivers/acpi/plat/arm-core.c
@@ -108,3 +108,24 @@ void __init acpi_boot_table_init(void)
return;
}
}
+
+static int __init parse_acpi(char *arg)
+{
+ if (!arg)
+ return -EINVAL;
+
+ /* acpi=off disables both ACPI table parsing and interpreter */
+ if (strcmp(arg, off) == 0) {
+ disable_acpi();
+ }
+ /* acpi=strict disables out-of-spec workarounds */
+ else if (strcmp(arg, strict) == 0) {
+ acpi_strict = 1;
+ } else {
+ /* Core will printk when we return error */
+ return -EINVAL;
+ }
+
+ return 0;
+}
+early_param(acpi, parse_acpi);
--
1.7.9.5
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