Commit ab930483 authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Rafael J. Wysocki
Browse files

ACPI: property: Fix return value for nval == 0 in acpi_data_prop_read() 



While analysing code for software and OF node for the corner case when
caller asks to read zero items in the supposed to be an array of values
I found that ACPI behaves differently to what OF does, i.e.

 1. It returns -EINVAL when caller asks to read zero items from integer
    array, while OF returns 0, if no other errors happened.

 2. It returns -EINVAL when caller asks to read zero items from string
    array, while OF returns -ENODATA, if no other errors happened.

Amend ACPI implementation to follow what OF does.

Fixes: b31384fa ("Driver core: Unified device properties interface for platform firmware")
Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20250203194629.3731895-1-andriy.shevchenko@linux.intel.com


[ rjw: Added empty line after a conditional ]
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 2014c95a

drivers/acpi/property.c

+5 −5
Original line number Diff line number Diff line
@@ -1187,8 +1187,6 @@ static int acpi_data_prop_read(const struct acpi_device_data *data, 
		}

		break;

	}

	if (nval == 0)

		return -EINVAL;



	if (obj->type == ACPI_TYPE_BUFFER) {

		if (proptype != DEV_PROP_U8)
@@ -1212,9 +1210,11 @@ static int acpi_data_prop_read(const struct acpi_device_data *data, 
		ret = acpi_copy_property_array_uint(items, (u64 *)val, nval);

		break;

	case DEV_PROP_STRING:

		ret = acpi_copy_property_array_string(

			items, (char **)val,

			min_t(u32, nval, obj->package.count));

		nval = min_t(u32, nval, obj->package.count);

		if (nval == 0)

			return -ENODATA;



		ret = acpi_copy_property_array_string(items, (char **)val, nval);

		break;

	default:

		ret = -EINVAL;