Hi Mika, There have some machines be found on openSUSE Tumbleweed that this patch causes that SSDT tables can not be dynamic loaded. The symptom is that dmesg shows '_CPC not found' because SSDT table did not dynamic load. [ 1.149107] ACPI BIOS Error (bug): Could not resolve symbol [\_PR.PR00._CPC], AE_NOT_FOUND (20210105/psargs-330) Looks that the firmware didn't response OSC_SB_CPCV2_SUPPORT after kernel changed to new behavior. The openSUSE bug is here: Bug 1185513 - ACPI BIOS Error after upgrade to 5.12.0-1-default https://bugzilla.suse.com/show_bug.cgi?id=1185513 Could you please help to give any suggestion? Thanks a lot! Joey Lee On Wed, Feb 03, 2021 at 10:14:15AM +0200, Mika Westerberg wrote: > Hi Rafael, > > I wonder if you are OK with this patch? > > Thanks! > > On Fri, Jan 29, 2021 at 11:32:39AM +0300, Mika Westerberg wrote: > > From: Mario Limonciello <mario.limonciello@xxxxxxxx> > > > > The platform _OSC can change the hardware state when query bit is not > > set. According to ACPI spec it is recommended that the OS runs _OSC with > > query bit set until the platform does not mask any of the capabilities. > > Then it should run it with query bit clear in order to actually commit > > the changes. Linux has not been doing this for the reasons that there > > has not been anything to commit, until now. > > > > The ACPI 6.4 introduced _OSC for USB4 to allow the OS to negotiate > > native control over USB4 tunneling. The platform might implement this so > > that it only activates the software connection manager path when the OS > > calls the _OSC with the query bit clear. Otherwise it may default to the > > firmware connection manager, for instance. > > > > For this reason modify the _OSC support so that we first execute it with > > query bit set, then use the returned value as base of the features we > > want to control and run the _OSC again with query bit clear. This also > > follows what Windows is doing. > > > > Also rename the function to better match what it does. > > > > Cc: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > > Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxxx> > > Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> > > --- > > drivers/acpi/bus.c | 43 +++++++++++++++++++++++++++++++------------ > > 1 file changed, 31 insertions(+), 12 deletions(-) > > > > diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c > > index 1682f8b454a2..a52cb28c40d8 100644 > > --- a/drivers/acpi/bus.c > > +++ b/drivers/acpi/bus.c > > @@ -282,9 +282,9 @@ bool osc_pc_lpi_support_confirmed; > > EXPORT_SYMBOL_GPL(osc_pc_lpi_support_confirmed); > > > > static u8 sb_uuid_str[] = "0811B06E-4A27-44F9-8D60-3CBBC22E7B48"; > > -static void acpi_bus_osc_support(void) > > +static void acpi_bus_osc_negotiate_platform_control(void) > > { > > - u32 capbuf[2]; > > + u32 capbuf[2], *capbuf_ret; > > struct acpi_osc_context context = { > > .uuid_str = sb_uuid_str, > > .rev = 1, > > @@ -321,17 +321,36 @@ static void acpi_bus_osc_support(void) > > capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_APEI_SUPPORT; > > if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle))) > > return; > > - if (ACPI_SUCCESS(acpi_run_osc(handle, &context))) { > > - u32 *capbuf_ret = context.ret.pointer; > > - if (context.ret.length > OSC_SUPPORT_DWORD) { > > - osc_sb_apei_support_acked = > > - capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_APEI_SUPPORT; > > - osc_pc_lpi_support_confirmed = > > - capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_PCLPI_SUPPORT; > > - } > > + > > + if (ACPI_FAILURE(acpi_run_osc(handle, &context))) > > + return; > > + > > + capbuf_ret = context.ret.pointer; > > + if (context.ret.length <= OSC_SUPPORT_DWORD) { > > kfree(context.ret.pointer); > > + return; > > } > > - /* do we need to check other returned cap? Sounds no */ > > + > > + /* > > + * Now run _OSC again with query flag clear and with the caps > > + * supported by both the OS and the platform. > > + */ > > + capbuf[OSC_QUERY_DWORD] = 0; > > + capbuf[OSC_SUPPORT_DWORD] = capbuf_ret[OSC_SUPPORT_DWORD]; > > + kfree(context.ret.pointer); > > + > > + if (ACPI_FAILURE(acpi_run_osc(handle, &context))) > > + return; > > + > > + capbuf_ret = context.ret.pointer; > > + if (context.ret.length > OSC_SUPPORT_DWORD) { > > + osc_sb_apei_support_acked = > > + capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_APEI_SUPPORT; > > + osc_pc_lpi_support_confirmed = > > + capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_PCLPI_SUPPORT; > > + } > > + > > + kfree(context.ret.pointer); > > } > > > > /* -------------------------------------------------------------------------- > > @@ -1168,7 +1187,7 @@ static int __init acpi_bus_init(void) > > * _OSC method may exist in module level code, > > * so it must be run after ACPI_FULL_INITIALIZATION > > */ > > - acpi_bus_osc_support(); > > + acpi_bus_osc_negotiate_platform_control(); > > > > /* > > * _PDC control method may load dynamic SSDT tables, > > -- > > 2.29.2
