From 96ff2ed501043e5099bc02cda6b2384e89126e24 Mon Sep 17 00:00:00 2001 From: Lekensteyn Date: Sat, 17 Dec 2011 19:14:47 +0100 Subject: [PATCH] bbswitch: always pass a Buffer object for empty args --- bbswitch.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/bbswitch.c b/bbswitch.c index ff989b8..f56b5da 100644 --- a/bbswitch.c +++ b/bbswitch.c @@ -68,7 +68,7 @@ static char *buffer_to_string(const char buffer[], char *target) { // succeeded, the result is stored in "result" providing that the result is an // integer or a buffer containing 4 values static int acpi_call_dsm(acpi_handle handle, const char muid[16], int revid, - int func, char *args, uint32_t *result) { + int func, char args[4], uint32_t *result) { struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL }; struct acpi_object_list input; union acpi_object params[4]; @@ -84,14 +84,14 @@ static int acpi_call_dsm(acpi_handle handle, const char muid[16], int revid, params[1].integer.value = revid; params[2].type = ACPI_TYPE_INTEGER; params[2].integer.value = func; + params[3].type = ACPI_TYPE_BUFFER; + params[3].buffer.length = 4; if (args) { - params[3].type = ACPI_TYPE_BUFFER; - params[3].buffer.length = sizeof(args); params[3].buffer.pointer = args; } else { - // this function does not accept arguments. Pass an empty one - params[3].type = ACPI_TYPE_INTEGER; - params[3].buffer.pointer = 0; + // Some implementations (Asus U36SD) seem to check the args before the + // function ID and crash if it is not a buffer. + params[3].buffer.pointer = (char[4]){0, 0, 0, 0}; } err = acpi_evaluate_object(handle, "_DSM", &input, &output);