soc/intel/common/block/pcie/rtd3: Skip Power On if _STA returns 1
RTD3,_ON method sometimes can create delays during system boot.
Even when the power is already up, kernel still tries to call _ON
method to power up device, but it's unnecessary.
RTD3._STA returns device power, so _ON method can check _STA and see
if the power on process can be skipped
BUG=b:249931687
TEST=system can boot to OS with RTD3 pcie storage and save ~80 ms on
Crota. Suspend stress test passes 100 cycles
Change-Id: I296ce1b85417a5dbaca558511cd7fc51a3a38c84
Signed-off-by: Kane Chen <kane.chen@intel.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/69189
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>
Reviewed-by: Subrata Banik <subratabanik@google.com>
diff --git a/src/soc/intel/common/block/pcie/rtd3/rtd3.c b/src/soc/intel/common/block/pcie/rtd3/rtd3.c
index f99ae44..7a64734 100644
--- a/src/soc/intel/common/block/pcie/rtd3/rtd3.c
+++ b/src/soc/intel/common/block/pcie/rtd3/rtd3.c
@@ -143,10 +143,30 @@
static void
pcie_rtd3_acpi_method_on(unsigned int pcie_rp,
const struct soc_intel_common_block_pcie_rtd3_config *config,
- enum pcie_rp_type rp_type)
+ enum pcie_rp_type rp_type,
+ const struct device *dev)
{
+ const struct device *parent = dev->bus->dev;
+
acpigen_write_method_serialized("_ON", 0);
+ /* The _STA returns current power status of device, so we can skip _ON
+ * if _STA returns 1
+ * Example:
+ * Local0 = \_SB.PCI0.RP01.RTD3._STA ()
+ * If ((Local0 == One))
+ * {
+ * Return (One)
+ * }
+ */
+ acpigen_write_store();
+ acpigen_emit_namestring(acpi_device_path_join(parent, "RTD3._STA"));
+ acpigen_emit_byte(LOCAL0_OP);
+ acpigen_write_if_lequal_op_int(LOCAL0_OP, ONE_OP);
+ acpigen_write_return_op(ONE_OP);
+ acpigen_write_if_end();
+
+
/* When this feature is enabled, ONSK indicates if the previous _OFF was
* skipped. If so, since the device was not in Off state, and the current
* _ON can be skipped as well.
@@ -448,7 +468,7 @@
}
pcie_rtd3_acpi_method_status(config);
- pcie_rtd3_acpi_method_on(pcie_rp, config, rp_type);
+ pcie_rtd3_acpi_method_on(pcie_rp, config, rp_type, dev);
pcie_rtd3_acpi_method_off(pcie_rp, config, rp_type);
acpigen_pop_len(); /* PowerResource */