| Message ID | 20170105142029.GF3353@lahna.fi.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On Thursday, January 05, 2017 04:20:29 PM Mika Westerberg wrote: > On Thu, Jan 05, 2017 at 12:49:40PM +0200, Mika Westerberg wrote: > > On Wed, Jan 04, 2017 at 10:58:10PM +0100, Rafael J. Wysocki wrote: > > > I would rather add a quirk to the ACPI core to prevent the power resources in > > > question from being enumerated. Or even to prevent ACPI PM from being > > > used for the port in question. > > > > If we are going to add a quirk, I agree that it should be put to the > > ACPI core. > > > > However, Windows seems to be able to use _PR3 just fine. So there is > > something that we are missing or do not implement properly which causes > > all the troubles. IMHO we should try to find out what that difference is > > and fix that if possible. > > Here is one idea. The _OSC method is used as a handshake between OS and > the BIOS to enable/disable certain features. One of those features is > _PR3 support (ACPI specification 6.1 p.328): > > This bit is set if OSPM supports reading _PR3and using power > resources to switch power. Note this handshake translates to an > operating model that the platform and OSPM supports both the power > model containing both D3hot and D3. Ah, good catch! I forgot about this one and we definitely should do this handshake. > Some of our development platforms has BIOS option "RTD3 enable" which > is used to enable/disable this flag (among other things). The BIOS > should return acked caps when _OSC returns but we never check those in > Linux. > > Kilian, can you try the below patch and send back dmesg when the system > has been booted? It should show if the BIOS acks _PR3 or not. > > diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c > index 95855cb9d6fb..463eb2d69271 100644 > --- a/drivers/acpi/bus.c > +++ b/drivers/acpi/bus.c > @@ -345,8 +345,15 @@ 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; > + > + acpi_handle_info(handle, "Supported caps: 0x%08x\n", capbuf[1]); > + > if (ACPI_SUCCESS(acpi_run_osc(handle, &context))) { > u32 *capbuf_ret = context.ret.pointer; > + > + acpi_handle_info(handle, "Acked caps: 0x%08x (_PR3: %s)\n", capbuf_ret[1], > + capbuf_ret[1] & OSC_SB_PR3_SUPPORT ? "on" : "off"); > + > if (context.ret.length > OSC_SUPPORT_DWORD) { > osc_sb_apei_support_acked = > capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_APEI_SUPPORT; > -- Thanks, Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c index 95855cb9d6fb..463eb2d69271 100644 --- a/drivers/acpi/bus.c +++ b/drivers/acpi/bus.c @@ -345,8 +345,15 @@ 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; + + acpi_handle_info(handle, "Supported caps: 0x%08x\n", capbuf[1]); + if (ACPI_SUCCESS(acpi_run_osc(handle, &context))) { u32 *capbuf_ret = context.ret.pointer; + + acpi_handle_info(handle, "Acked caps: 0x%08x (_PR3: %s)\n", capbuf_ret[1], + capbuf_ret[1] & OSC_SB_PR3_SUPPORT ? "on" : "off"); + if (context.ret.length > OSC_SUPPORT_DWORD) { osc_sb_apei_support_acked = capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_APEI_SUPPORT;