On Mon, Sep 05, 2022 at 12:55:31PM +0530, Ani Sinha wrote: > Possible fix for https://bugzilla.redhat.com/show_bug.cgi?id=2089545 > > Change in AML: > > @@ -47,33 +47,39 @@ > Scope (_SB) > { > Device (PCI0) > { > Name (_HID, EisaId ("PNP0A08") /* PCI Express Bus */) // _HID: > Hardware ID > Name (_CID, EisaId ("PNP0A03") /* PCI Bus */) // _CID: > Compatible ID > Name (_ADR, Zero) // _ADR: Address > Name (_UID, Zero) // _UID: Unique ID > Method (_OSC, 4, NotSerialized) // _OSC: Operating System > Capabilities > { > CreateDWordField (Arg3, Zero, CDW1) > If ((Arg0 == ToUUID ("33db4d5b-1ff7-401c-9657-7441c03dd766") > /* PCI Host Bridge Device */)) > { > CreateDWordField (Arg3, 0x04, CDW2) > CreateDWordField (Arg3, 0x08, CDW3) > Local0 = CDW3 /* \_SB_.PCI0._OSC.CDW3 */ > - Local0 &= 0x1E > + Local0 &= 0x1F > + Local1 = (CDW3 & One) > + If ((One == Local1)) > + { > + CDW1 |= 0x12 > + } > + > If ((Arg1 != One)) > { > CDW1 |= 0x08 > } > > If ((CDW3 != Local0)) > { > CDW1 |= 0x10 > } > > CDW3 = Local0 > } > Else > { > CDW1 |= 0x04 > } > ** > > Signed-off-by: Ani Sinha <a...@anisinha.ca> > --- > hw/i386/acpi-build.c | 23 ++++++++++++++++++++--- > 1 file changed, 20 insertions(+), 3 deletions(-) > > diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c > index 0355bd3dda..3dc9379f27 100644 > --- a/hw/i386/acpi-build.c > +++ b/hw/i386/acpi-build.c > @@ -1348,10 +1348,12 @@ static Aml *build_q35_osc_method(bool > enable_native_pcie_hotplug) > { > Aml *if_ctx; > Aml *if_ctx2; > + Aml *if_ctx3; > Aml *else_ctx; > Aml *method; > Aml *a_cwd1 = aml_name("CDW1"); > Aml *a_ctrl = aml_local(0); > + Aml *a_pcie_nhp_ctl = aml_local(1); > > method = aml_method("_OSC", 4, AML_NOTSERIALIZED); > aml_append(method, aml_create_dword_field(aml_arg(3), aml_int(0), > "CDW1")); > @@ -1366,11 +1368,26 @@ static Aml *build_q35_osc_method(bool > enable_native_pcie_hotplug) > /* > * Always allow native PME, AER (no dependencies) > * Allow SHPC (PCI bridges can have SHPC controller) > - * Disable PCIe Native Hot-plug if ACPI PCI Hot-plug is enabled. > */ > - aml_append(if_ctx, aml_and(a_ctrl, > - aml_int(0x1E | (enable_native_pcie_hotplug ? 0x1 : 0x0)), a_ctrl)); > + aml_append(if_ctx, aml_and(a_ctrl, aml_int(0x1F), a_ctrl)); > > + /* > + * if ACPI PCI Hot-plug is enabled, do not let OSPM set OSC PCIE > + * Native hotplug ctrl bit. > + */ > + if (!enable_native_pcie_hotplug) { > + /* check if the ACPI native hotplug bit is set by the OS in DWORD3 */ > + aml_append(if_ctx, aml_and(aml_name("CDW3"), > + aml_int(0x01), a_pcie_nhp_ctl)); > + if_ctx3 = aml_if(aml_equal(aml_int(1), a_pcie_nhp_ctl)); > + /* > + * ACPI spec 5.1, section 6.2.11 > + * bit 1 in first DWORD - _OSC failure > + * bit 4 in first DWORD - capabilities masked > + */ > + aml_append(if_ctx3, aml_or(a_cwd1, aml_int(0x12), a_cwd1));
0x12 -> ( 0x1 << 4 ) /* _OSC failure */ | ( 0x1 << 1) /* capabilities masked */ > + aml_append(if_ctx, if_ctx3); > + } > if_ctx2 = aml_if(aml_lnot(aml_equal(aml_arg(1), aml_int(1)))); > /* Unknown revision */ > aml_append(if_ctx2, aml_or(a_cwd1, aml_int(0x08), a_cwd1)); Hmm wait a sec if_ctx2 = aml_if(aml_lnot(aml_equal(aml_name("CDW3"), a_ctrl))); /* Capabilities bits were masked */ aml_append(if_ctx2, aml_or(a_cwd1, aml_int(0x10), a_cwd1)); aml_append(if_ctx, if_ctx2); this one seems subtly different ... > -- > 2.34.1