commit 325aa2d86a20786c308b0874d15a60d1b924bd0e
author Eric Auger <eric.auger@redhat.com> Wed Oct 22 09:06:38 2025 +0100
committer Michael S. Tsirkin <mst@redhat.com> Sun Nov 09 08:24:29 2025 -0500
tree 0865263342282833f0fca1cfb051c8b2198bd638
parent 3e6ad83f209ea8cf497e5d160e44c1bc5e518f1a

hw/pci-host/gpex-acpi: Fix _DSM function 0 support return value

Currently, only function 0 is supported. According to the ACPI
Specification, Revision 6.6, Section 9.1.1 “_DSM (Device Specific
Method)”, bit 0 should be 0 to indicate that no other functions
are supported beyond function 0.

The resulting AML change looks like this:

Method (_DSM, 4, NotSerialized)  // _DSM: Device-Specific Method
{
    If ((Arg0 == ToUUID ("e5c937d0-3553-4d7a-9117-ea4d19c3434d")
    {
        If ((Arg2 == Zero))
        {
            Return (Buffer (One)
            {
-               0x01                                             // .
+               0x00                                             // .
            })
        }
    }
}

Fixes: 5b85eabe68f9 ("acpi: add acpi_dsdt_add_gpex")
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Shameer Kolothum <skolothumtho@nvidia.com>
Tested-by: Zhangfei Gao <zhangfei.gao@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20251022080639.243965-3-skolothumtho@nvidia.com>