[PATCH v13 06/12] ACPI: x86: s2idle: Fix a logic error parsing AMD constraints table

From: Mario Limonciello
Date: Fri Aug 18 2023 - 01:17:57 EST


The constraints table should be resetting the `list` object
after running through all of `info_obj` iterations.

This adjusts whitespace as well as less code will now be included
with each loop. This fixes a functional problem is fixed where a
badly formed package in the inner loop may have incorrect data.

Fixes: 146f1ed852a8 ("ACPI: PM: s2idle: Add AMD support to handle _DSM")
Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
---
v11->v12:
* Update commit message
v9->v10:
* split from other patches
---
drivers/acpi/x86/s2idle.c | 31 ++++++++++++-------------------
1 file changed, 12 insertions(+), 19 deletions(-)

diff --git a/drivers/acpi/x86/s2idle.c b/drivers/acpi/x86/s2idle.c
index 508decbac2986..60835953ebfc4 100644
--- a/drivers/acpi/x86/s2idle.c
+++ b/drivers/acpi/x86/s2idle.c
@@ -135,12 +135,11 @@ static void lpi_device_get_constraints_amd(void)
struct lpi_constraints *list;
acpi_status status;

+ list = &lpi_constraints_table[lpi_constraints_table_size];
+
for (k = 0; k < info_obj->package.count; k++) {
union acpi_object *obj = &info_obj->package.elements[k];

- list = &lpi_constraints_table[lpi_constraints_table_size];
- list->min_dstate = -1;
-
switch (k) {
case 0:
dev_info.enabled = obj->integer.value;
@@ -155,27 +154,21 @@ static void lpi_device_get_constraints_amd(void)
dev_info.min_dstate = obj->integer.value;
break;
}
+ }

- if (!dev_info.enabled || !dev_info.name ||
- !dev_info.min_dstate)
- continue;
+ if (!dev_info.enabled || !dev_info.name ||
+ !dev_info.min_dstate)
+ continue;

- status = acpi_get_handle(NULL, dev_info.name,
- &list->handle);
- if (ACPI_FAILURE(status))
- continue;
+ status = acpi_get_handle(NULL, dev_info.name, &list->handle);
+ if (ACPI_FAILURE(status))
+ continue;

- acpi_handle_debug(lps0_device_handle,
- "Name:%s\n", dev_info.name);
+ acpi_handle_debug(lps0_device_handle,
+ "Name:%s\n", dev_info.name);

- list->min_dstate = dev_info.min_dstate;
+ list->min_dstate = dev_info.min_dstate;

- if (list->min_dstate < 0) {
- acpi_handle_debug(lps0_device_handle,
- "Incomplete constraint defined\n");
- continue;
- }
- }
lpi_constraints_table_size++;
}
}
--
2.34.1