diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c index fae79cdd3610..c1876f145ae4 100644 --- a/drivers/acpi/bus.c +++ b/drivers/acpi/bus.c @@ -335,7 +335,7 @@ static int acpi_osc_handshake(acpi_handle handle, const char *uuid_str, .length = bufsize * sizeof(u32), }; struct acpi_buffer output; - u32 *retbuf, test; + u32 *retbuf, test, errors; guid_t guid; int ret, i; @@ -395,10 +395,18 @@ static int acpi_osc_handshake(acpi_handle handle, const char *uuid_str, * Clear the feature bits in capbuf[] that have not been acknowledged. * After that, capbuf[] contains the resultant feature mask. */ - for (i = OSC_QUERY_DWORD + 1; i < bufsize; i++) + for (i = OSC_QUERY_DWORD + 1, test = 0; i < bufsize; i++) { + test |= capbuf[i] & ~retbuf[i]; capbuf[i] &= retbuf[i]; + } - if (retbuf[OSC_QUERY_DWORD] & OSC_ERROR_MASK) { + errors = retbuf[OSC_QUERY_DWORD] & OSC_ERROR_MASK; + /* + * Some platforms set OSC_CAPABILITIES_MASK_ERROR even though they + * acknowledge all of the requested features, so avoid complaining in + * those cases unless any other error bits are also set. + */ + if (errors && (test || errors != OSC_CAPABILITIES_MASK_ERROR)) { /* * Complain about the unexpected errors and print diagnostic * information related to them.