table_compute_checksum() returns the value that makes the byte sum of the buffer zero. If the ext_checksum field already contains a non-zero value (as QEMU's firmware-provided RSDP does), adding that existing value into the sum produces an incorrect complement. Zero the field before calling table_compute_checksum() so the calculation starts from a clean state, matching the pattern used in acpi_write_rsdp().
Signed-off-by: Heinrich Schuchardt <[email protected]> --- v2: new patch --- drivers/misc/qfw_acpi.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/misc/qfw_acpi.c b/drivers/misc/qfw_acpi.c index 721f42ecbc3..afa3b820395 100644 --- a/drivers/misc/qfw_acpi.c +++ b/drivers/misc/qfw_acpi.c @@ -265,6 +265,7 @@ out: struct acpi_rsdp *rsdp = ctx->rsdp; rsdp->length = sizeof(*rsdp); + rsdp->ext_checksum = 0; rsdp->ext_checksum = table_compute_checksum((u8 *)rsdp, sizeof(*rsdp)); gd_set_acpi_start(acpi_get_rsdp_addr()); -- 2.53.0
