diff options
| author | Zhuo-hao Lee <zhuo-hao.lee@intel.com> | 2017-03-14 10:27:28 +0800 |
|---|---|---|
| committer | Aaron Durbin <adurbin@chromium.org> | 2017-03-17 03:36:09 +0100 |
| commit | 07f60aa56fefa0aeb4f896d63267a54ddfae0715 (patch) | |
| tree | 4ea54d893074df433f7c5f24e75fdd4abf30c930 /src/soc | |
| parent | 6f80ccc357702f87baf43440d97a49bcce999393 (diff) | |
| download | coreboot-07f60aa56fefa0aeb4f896d63267a54ddfae0715.tar.xz | |
soc/intel/apollolake: Reduce D3 cold delay for eMMC controller
eMMC Controller is taking over 100ms to resume during runtime which
results in I/O latency issues on the Apollo Lake system such as Snappy.
The cause is the Linux Kernel setting the firmware reset time to
100 ms by default.
This patch adds _DSM method for eMMC comtroller for specifying the
device readiness durations. Function index 9 returns package of five
integers to set D3 cold delay to zero and ACPI constant Ones for the
elements where overriding the default values is not desired.
BUG=b:35774937
BRANCH=none
TEST=update snappy coreboot and test i/o latency is under 100ms
Signed-off-by: Zhuo-hao Lee <zhuo-hao.lee@intel.com>
Signed-off-by: Sowmya V <v.sowmya@intel.com>
Change-Id: Idcfe4252b20bead15c2e5b9cb000ff797295f06a
Reviewed-on: https://review.coreboot.org/18806
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Diffstat (limited to 'src/soc')
| -rw-r--r-- | src/soc/intel/apollolake/acpi/scs.asl | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/src/soc/intel/apollolake/acpi/scs.asl b/src/soc/intel/apollolake/acpi/scs.asl index 05aedca5a4..f69f43cda5 100644 --- a/src/soc/intel/apollolake/acpi/scs.asl +++ b/src/soc/intel/apollolake/acpi/scs.asl @@ -47,6 +47,49 @@ Scope (\_SB.PCI0) { Device (SDHA) { Name (_ADR, 0x001C0000) Name (_DDN, "Intel(R) eMMC Controller - 80865ACC") + Name (UUID, ToUUID ("E5C937D0-3553-4D7A-9117-EA4D19C3434D")) + + /* + * Device Specific Method + * Arg0 - UUID + * Arg1 - Revision + * Arg2 - Function Index + */ + Method (_DSM, 4) + { + If (LEqual (Arg0, ^UUID)) { + /* + * Function 9: Device Readiness Durations + * Returns a package of five integers covering + * various device related delays in PCIe Base Spec. + */ + If (LEqual (Arg2, 9)) { + /* + * Function 9 support for revision 3. + * ECN link for function definitions + * [https://pcisig.com/sites/default/files/ + * specification_documents/ + * ECN_fw_latency_optimization_final.pdf] + */ + If (LEqual (Arg1, 3)) { + /* + * Integer 0: FW reset time. + * Integer 1: FW data link up time. + * Integer 2: FW functional level reset + * time. + * Integer 3: FW D3 hot to D0 time. + * Integer 4: FW VF enable time. + * set ACPI constant Ones for elements + * where overriding the default value + * is not desired. + */ + Return (Package (5) {0, Ones, Ones, + Ones, Ones}) + } + } + } + Return (Buffer() { 0x00 }) + } Method (_PS0, 0, NotSerialized) { |