Add a wrapper function to read the _SUB string from ACPI.
Signed-off-by: Stefan Binding <[email protected]>
---
drivers/acpi/utils.c | 26 ++++++++++++++++++++++++++
include/linux/acpi.h | 8 ++++++++
2 files changed, 34 insertions(+)
diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
index 3a9773a09e19..5d1bdb79e372 100644
--- a/drivers/acpi/utils.c
+++ b/drivers/acpi/utils.c
@@ -291,6 +291,32 @@ int acpi_get_local_address(acpi_handle handle, u32 *addr)
}
EXPORT_SYMBOL(acpi_get_local_address);
+int acpi_get_sub(acpi_handle handle, char *sub, size_t size)
+{
+ struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+ union acpi_object *obj;
+ acpi_status status;
+ int ret;
+
+ status = acpi_evaluate_object(handle, METHOD_NAME__SUB, NULL, &buffer);
+ if (!ACPI_SUCCESS(status)) {
+ acpi_handle_debug(handle, "Reading ACPI _SUB failed: %#x\n", status);
+ return -ENOENT;
+ }
+
+ obj = buffer.pointer;
+ if (obj->type == ACPI_TYPE_STRING) {
+ ret = strscpy(sub, obj->string.pointer, size);
+ } else {
+ acpi_handle_warn(handle, "Warning ACPI _SUB did not return a string\n");
+ ret = -EINVAL;
+ }
+ acpi_os_free(buffer.pointer);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(acpi_get_sub);
+
acpi_status
acpi_evaluate_reference(acpi_handle handle,
acpi_string pathname,
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 4f82a5bc6d98..9bf18adf5920 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -21,6 +21,8 @@
#endif
#include <acpi/acpi.h>
+#define ACPI_MAX_SUB_BUF_SIZE 9
+
#ifdef CONFIG_ACPI
#include <linux/list.h>
@@ -762,6 +764,7 @@ static inline u64 acpi_arch_get_root_pointer(void)
#endif
int acpi_get_local_address(acpi_handle handle, u32 *addr);
+int acpi_get_sub(acpi_handle handle, char *sub, size_t size);
#else /* !CONFIG_ACPI */
@@ -1023,6 +1026,11 @@ static inline int acpi_get_local_address(acpi_handle handle, u32 *addr)
return -ENODEV;
}
+static int acpi_get_sub(acpi_handle handle, char *sub, size_t size)
+{
+ return -ENODEV;
+}
+
static inline int acpi_register_wakeup_handler(int wake_irq,
bool (*wakeup)(void *context), void *context)
{
--
2.25.1
On Wed, Jun 22, 2022 at 3:08 PM Stefan Binding
<[email protected]> wrote:
>
> Add a wrapper function to read the _SUB string from ACPI.
>
> Signed-off-by: Stefan Binding <[email protected]>
> ---
> drivers/acpi/utils.c | 26 ++++++++++++++++++++++++++
> include/linux/acpi.h | 8 ++++++++
> 2 files changed, 34 insertions(+)
>
> diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
> index 3a9773a09e19..5d1bdb79e372 100644
> --- a/drivers/acpi/utils.c
> +++ b/drivers/acpi/utils.c
> @@ -291,6 +291,32 @@ int acpi_get_local_address(acpi_handle handle, u32 *addr)
> }
> EXPORT_SYMBOL(acpi_get_local_address);
>
> +int acpi_get_sub(acpi_handle handle, char *sub, size_t size)
I'd call it acpi_get_subsystem_id().
> +{
> + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
> + union acpi_object *obj;
> + acpi_status status;
> + int ret;
> +
> + status = acpi_evaluate_object(handle, METHOD_NAME__SUB, NULL, &buffer);
> + if (!ACPI_SUCCESS(status)) {
Typically, ACPI_FAILURE() is used in checks like this.
> + acpi_handle_debug(handle, "Reading ACPI _SUB failed: %#x\n", status);
It would be enough to say "_SUB evaluation failed".
> + return -ENOENT;
Why not use -ENODATA here?
> + }
> +
> + obj = buffer.pointer;
> + if (obj->type == ACPI_TYPE_STRING) {
> + ret = strscpy(sub, obj->string.pointer, size);
It may be simpler to allocate the memory here so that callers don't
have to worry about it.
Also, this is expected to be a proper device ID, not just a string, so
maybe some validation checks could be made here?
> + } else {
> + acpi_handle_warn(handle, "Warning ACPI _SUB did not return a string\n");
> + ret = -EINVAL;
> + }
> + acpi_os_free(buffer.pointer);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(acpi_get_sub);
> +
> acpi_status
> acpi_evaluate_reference(acpi_handle handle,
> acpi_string pathname,
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index 4f82a5bc6d98..9bf18adf5920 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -21,6 +21,8 @@
> #endif
> #include <acpi/acpi.h>
>
> +#define ACPI_MAX_SUB_BUF_SIZE 9
> +
> #ifdef CONFIG_ACPI
>
> #include <linux/list.h>
> @@ -762,6 +764,7 @@ static inline u64 acpi_arch_get_root_pointer(void)
> #endif
>
> int acpi_get_local_address(acpi_handle handle, u32 *addr);
> +int acpi_get_sub(acpi_handle handle, char *sub, size_t size);
>
> #else /* !CONFIG_ACPI */
>
> @@ -1023,6 +1026,11 @@ static inline int acpi_get_local_address(acpi_handle handle, u32 *addr)
> return -ENODEV;
> }
>
> +static int acpi_get_sub(acpi_handle handle, char *sub, size_t size)
> +{
> + return -ENODEV;
> +}
> +
> static inline int acpi_register_wakeup_handler(int wake_irq,
> bool (*wakeup)(void *context), void *context)
> {
> --
Hi Stefan,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on rafael-pm/linux-next]
[also build test ERROR on broonie-sound/for-next linus/master v5.19-rc3 next-20220622]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/intel-lab-lkp/linux/commits/Stefan-Binding/Read-_SUB-from-ACPI-to-be-able-to-identify-firmware/20220622-211004
base: https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
config: powerpc-buildonly-randconfig-r002-20220622 (https://download.01.org/0day-ci/archive/20220623/[email protected]/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 8b8d126598ce7bd5243da7f94f69fa1104288bee)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install powerpc cross compiling tool for clang build
# apt-get install binutils-powerpc-linux-gnu
# https://github.com/intel-lab-lkp/linux/commit/97b928a895ce3105296f0036393bb9ee04f11ae4
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Stefan-Binding/Read-_SUB-from-ACPI-to-be-able-to-identify-firmware/20220622-211004
git checkout 97b928a895ce3105296f0036393bb9ee04f11ae4
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=powerpc SHELL=/bin/bash arch/powerpc/
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <[email protected]>
All errors (new ones prefixed by >>):
In file included from arch/powerpc/kernel/traps.c:32:
In file included from include/linux/backlight.h:13:
In file included from include/linux/fb.h:7:
In file included from include/uapi/linux/fb.h:6:
In file included from include/linux/i2c.h:13:
>> include/linux/acpi.h:1029:12: error: unused function 'acpi_get_sub' [-Werror,-Wunused-function]
static int acpi_get_sub(acpi_handle handle, char *sub, size_t size)
^
1 error generated.
vim +/acpi_get_sub +1029 include/linux/acpi.h
1028
> 1029 static int acpi_get_sub(acpi_handle handle, char *sub, size_t size)
1030 {
1031 return -ENODEV;
1032 }
1033
--
0-DAY CI Kernel Test Service
https://01.org/lkp
Hi Stefan,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on rafael-pm/linux-next]
[also build test ERROR on broonie-sound/for-next linus/master v5.19-rc3 next-20220622]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/intel-lab-lkp/linux/commits/Stefan-Binding/Read-_SUB-from-ACPI-to-be-able-to-identify-firmware/20220622-211004
base: https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
config: powerpc-pasemi_defconfig (https://download.01.org/0day-ci/archive/20220623/[email protected]/config)
compiler: powerpc-linux-gcc (GCC) 11.3.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/97b928a895ce3105296f0036393bb9ee04f11ae4
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Stefan-Binding/Read-_SUB-from-ACPI-to-be-able-to-identify-firmware/20220622-211004
git checkout 97b928a895ce3105296f0036393bb9ee04f11ae4
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross W=1 O=build_dir ARCH=powerpc SHELL=/bin/bash
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <[email protected]>
All errors (new ones prefixed by >>):
In file included from include/linux/i2c.h:13,
from include/uapi/linux/fb.h:6,
from include/linux/fb.h:7,
from include/linux/backlight.h:13,
from arch/powerpc/kernel/traps.c:32:
>> include/linux/acpi.h:1029:12: error: 'acpi_get_sub' defined but not used [-Werror=unused-function]
1029 | static int acpi_get_sub(acpi_handle handle, char *sub, size_t size)
| ^~~~~~~~~~~~
cc1: all warnings being treated as errors
vim +/acpi_get_sub +1029 include/linux/acpi.h
1028
> 1029 static int acpi_get_sub(acpi_handle handle, char *sub, size_t size)
1030 {
1031 return -ENODEV;
1032 }
1033
--
0-DAY CI Kernel Test Service
https://01.org/lkp