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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>
This commit is contained in:
Kane Chen 2022-11-03 23:18:44 +08:00 committed by Felix Held
parent 778c7af37a
commit 11be5562b2
1 changed files with 22 additions and 2 deletions
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24
src/soc/intel/common/block/pcie/rtd3/rtd3.c
View File

@ -143,10 +143,30 @@ static void pcie_rtd3_acpi_method_srck(unsigned int pcie_rp,
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 @@ static void pcie_rtd3_acpi_fill_ssdt(const struct device *dev)
}
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 */