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: b31384fa5de3 ("Driver core: Unified device properties interface for platform firmware")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/acpi/property.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
index 1144c2368d89..7d7f4974c5b1 100644
--- a/drivers/acpi/property.c
+++ b/drivers/acpi/property.c
@@ -1189,8 +1189,6 @@ static int acpi_data_prop_read(const struct acpi_device_data *data,
return -EOVERFLOW;
break;
}
- if (nval == 0)
- return -EINVAL;
if (obj->type == ACPI_TYPE_BUFFER) {
if (proptype != DEV_PROP_U8)
@@ -1214,9 +1212,10 @@ 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;
--
2.43.0.rc1.1336.g36b5255a03ac
