Re: [PATCH v11 6/9] ACPI: x86: s2idle: Add a function to get constraints for a device

From: Limonciello, Mario
Date: Thu Aug 10 2023 - 11:54:21 EST




On 8/10/2023 10:47 AM, Andy Shevchenko wrote:
On Wed, Aug 09, 2023 at 01:54:50PM -0500, Mario Limonciello wrote:
Other parts of the kernel may use constraints information to make
decisions on what power state to put a device into.

...

+int acpi_get_lps0_constraint(struct device *dev)
+{

+ int i;
+
+ for (i = 0; i < lpi_constraints_table_size; ++i) {
+ static struct lpi_constraints *entry;

static?!

Whoops! Good catch!


Seems to me with the code in lpi_check_constraints() this actually can be first
(separate patch maybe with conversion of the mentioned user) transformed to

#define for_each_lpi_constraint(entry)
for (int i = 0;
entry = &lpi_constraints_table[i], i < lpi_constraints_table_size;
i++)

+ int val;
+
+ entry = &lpi_constraints_table[i];
+ if (!device_match_acpi_handle(dev, entry->handle))
+ continue;
+ val = entry->enabled ? entry->min_dstate : 0;
+ acpi_handle_debug(entry->handle,
+ "ACPI device constraint: %d\n", val);
+ return val;
+ }

So will become

struct lpi_constraints *entry;
int val;

for_each_lpi_constraint(entry) {
if (!device_match_acpi_handle(dev, entry->handle))
continue;
val = entry->enabled ? entry->min_dstate : 0;
acpi_handle_debug(entry->handle,
"ACPI device constraint: %d\n", val);
return val;
}

+ return -ENODEV;
+}


Much appreciated suggestion. I'll incorporate this in the next version.