diff options
| -rw-r--r-- | src/arch/x86/acpi_device.c | 42 |
1 files changed, 26 insertions, 16 deletions
diff --git a/src/arch/x86/acpi_device.c b/src/arch/x86/acpi_device.c index 48b7fee26c..c62d6f3688 100644 --- a/src/arch/x86/acpi_device.c +++ b/src/arch/x86/acpi_device.c @@ -632,7 +632,7 @@ static void acpi_dp_free(struct acpi_dp *dp) void acpi_dp_write(struct acpi_dp *table) { struct acpi_dp *dp, *prop; - char *dp_count, *prop_count; + char *dp_count, *prop_count = NULL; int child_count = 0; if (!table || table->type != ACPI_DP_TYPE_TABLE) @@ -644,32 +644,42 @@ void acpi_dp_write(struct acpi_dp *table) /* Device Property list starts with the next entry */ prop = table->next; - /* Package (DP), default to 2 elements (assuming no children) */ - dp_count = acpigen_write_package(2); - - /* ToUUID (ACPI_DP_UUID) */ - acpigen_write_uuid(ACPI_DP_UUID); - - /* Package (PROP), element count determined as it is populated */ - prop_count = acpigen_write_package(0); + /* Package (DP), default to assuming no properties or children */ + dp_count = acpigen_write_package(0); /* Print base properties */ for (dp = prop; dp; dp = dp->next) { if (dp->type == ACPI_DP_TYPE_CHILD) { child_count++; } else { + /* + * The UUID and package is only added when + * we come across the first property. This + * is to avoid creating a zero-length package + * in situations where there are only children. + */ + if (!prop_count) { + *dp_count += 2; + /* ToUUID (ACPI_DP_UUID) */ + acpigen_write_uuid(ACPI_DP_UUID); + /* + * Package (PROP), element count determined as + * it is populated + */ + prop_count = acpigen_write_package(0); + } (*prop_count)++; acpi_dp_write_property(dp); } } - - /* Package (PROP) length */ - acpigen_pop_len(); + if (prop_count) { + /* Package (PROP) length, if a package was written */ + acpigen_pop_len(); + } if (child_count) { - /* Update DP package count to 4 */ - *dp_count = 4; - + /* Update DP package count to 2 or 4 */ + *dp_count += 2; /* ToUUID (ACPI_DP_CHILD_UUID) */ acpigen_write_uuid(ACPI_DP_CHILD_UUID); @@ -679,7 +689,7 @@ void acpi_dp_write(struct acpi_dp *table) for (dp = prop; dp; dp = dp->next) if (dp->type == ACPI_DP_TYPE_CHILD) acpi_dp_write_property(dp); - + /* Package (CHILD) length */ acpigen_pop_len(); } |