[PATCH][v2] ACPI: processor: Print more information when acpi_processor_evaluate_cst() failed

From: Chen Yu
Date: Tue Aug 18 2020 - 23:22:48 EST


Some platforms have bogus _CST which might cause expectd behavior
in the cpu idle driver. Some bogus _CST might be unable to be
disassembled by acpica-tools due to broken format.
Print extra log if the _CST extraction/verification failed.
This can be used to help the user narrow down why the cpu
idle driver fails to behave as expected.

Suggested-by: Zhang Rui <rui.zhang@xxxxxxxxx>
Signed-off-by: Chen Yu <yu.c.chen@xxxxxxxxx>
---
v2: According to Rafael's suggestion, change the log level
from "warn" to "info"
---
drivers/acpi/acpi_processor.c | 34 ++++++++++++++++++++++++++++------
1 file changed, 28 insertions(+), 6 deletions(-)

diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
index b51ddf3bb616..412a9725cc1e 100644
--- a/drivers/acpi/acpi_processor.c
+++ b/drivers/acpi/acpi_processor.c
@@ -798,22 +798,34 @@ int acpi_processor_evaluate_cst(acpi_handle handle, u32 cpu,
memset(&cx, 0, sizeof(cx));

element = &cst->package.elements[i];
- if (element->type != ACPI_TYPE_PACKAGE)
+ if (element->type != ACPI_TYPE_PACKAGE) {
+ acpi_handle_info(handle, "_CST C%d type(%x) is not package, skip...\n",
+ i, element->type);
continue;
+ }

- if (element->package.count != 4)
+ if (element->package.count != 4) {
+ acpi_handle_info(handle, "_CST C%d package count(%d) is not 4, skip...\n",
+ i, element->package.count);
continue;
+ }

obj = &element->package.elements[0];

- if (obj->type != ACPI_TYPE_BUFFER)
+ if (obj->type != ACPI_TYPE_BUFFER) {
+ acpi_handle_info(handle, "_CST C%d package element[0] type(%x) is not buffer, skip...\n",
+ i, obj->type);
continue;
+ }

reg = (struct acpi_power_register *)obj->buffer.pointer;

obj = &element->package.elements[1];
- if (obj->type != ACPI_TYPE_INTEGER)
+ if (obj->type != ACPI_TYPE_INTEGER) {
+ acpi_handle_info(handle, "_CST C[%d] package element[1] type(%x) is not integer, skip...\n",
+ i, obj->type);
continue;
+ }

cx.type = obj->integer.value;
/*
@@ -850,6 +862,8 @@ int acpi_processor_evaluate_cst(acpi_handle handle, u32 cpu,
cx.entry_method = ACPI_CSTATE_HALT;
snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
} else {
+ acpi_handle_info(handle, "_CST C%d declares FIXED_HARDWARE C-state but not supported in hardware, skip...\n",
+ i);
continue;
}
} else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
@@ -857,6 +871,8 @@ int acpi_processor_evaluate_cst(acpi_handle handle, u32 cpu,
snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
cx.address);
} else {
+ acpi_handle_info(handle, "_CST C%d space_id(%x) neither FIXED_HARDWARE nor SYSTEM_IO, skip...\n",
+ i, reg->space_id);
continue;
}

@@ -864,14 +880,20 @@ int acpi_processor_evaluate_cst(acpi_handle handle, u32 cpu,
cx.valid = 1;

obj = &element->package.elements[2];
- if (obj->type != ACPI_TYPE_INTEGER)
+ if (obj->type != ACPI_TYPE_INTEGER) {
+ acpi_handle_info(handle, "_CST C%d package element[2] type(%x) not integer, skip...\n",
+ i, obj->type);
continue;
+ }

cx.latency = obj->integer.value;

obj = &element->package.elements[3];
- if (obj->type != ACPI_TYPE_INTEGER)
+ if (obj->type != ACPI_TYPE_INTEGER) {
+ acpi_handle_info(handle, "_CST C%d package element[3] type(%x) not integer, skip...\n",
+ i, obj->type);
continue;
+ }

memcpy(&info->states[++last_index], &cx, sizeof(cx));
}
--
2.17.1