L1 PM Substates is a new PCI power management feature that can enable
lower power consumption when a PCIe Link is idle. This change to the PCI
Base Specification is reflected in the PCI-SIG ECN titled
"L1 PM Substates with CLKREQ".
Signed-off-by: David E. Box <david.e.box@xxxxxxxxxxxxxxx>
---
lib/header.h | 1 +
ls-ecaps.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 55 insertions(+)
diff --git a/lib/header.h b/lib/header.h
index 69518fd..6608003 100644
--- a/lib/header.h
+++ b/lib/header.h
@@ -226,6 +226,7 @@
#define PCI_EXT_CAP_ID_SRIOV 0x10 /* Single Root I/O Virtualization */
#define PCI_EXT_CAP_ID_TPH 0x17 /* Transaction processing hints */ #define
PCI_EXT_CAP_ID_LTR 0x18 /* Latency Tolerance Reporting */
+#define PCI_EXT_CAP_ID_L1PM 0x1e /* L1 PM Substates */
/*** Definitions of capabilities ***/
diff --git a/ls-ecaps.c b/ls-ecaps.c
index 161c275..7b28ce5 100644
--- a/ls-ecaps.c
+++ b/ls-ecaps.c
@@ -448,6 +448,57 @@ cap_evendor(struct device *d, int where)
BITS(hdr, 20, 12));
}
+static void
+cap_l1pm(struct device *d, int where)
+{
+ u32 l1_cap;
+ int power_on_scale;
+
+ printf("L1 PM Substates\n");
+
+ if (verbose < 2)
+ return;
+
+ if (!config_fetch(d, where + 4, 4)) {
+ printf("\t\t<unreadable>\n");
+ return;
+ }
+
+ l1_cap = get_conf_long(d, where + 4);
+
+ printf("\t\tL1SubCap: ");
+ printf("PCI-PM_L1.2%c, PCI-PM_L1.1%c, ASPM_L1.2%c, ASPM_L1.1%c," + "
L1_PM_Substates%c\n",
+ FLAG(l1_cap, 1),
+ FLAG(l1_cap, 2),
+ FLAG(l1_cap, 4),
+ FLAG(l1_cap, 8),
+ FLAG(l1_cap, 16));
+
+ if (BITS(l1_cap, 0, 1) || BITS(l1_cap, 2, 1)) {
+ printf("\t\t\t PortCommonModeRestoreTime=%dus, ",
+ BITS(l1_cap, 8,8));
+
+ power_on_scale = BITS(l1_cap, 16, 2);
+
+ printf("PortTPowerOnTime=");
+ switch (power_on_scale) {
+ case 0:
+ printf("%dus\n", BITS(l1_cap, 19, 5) * 2);
+ break;
+ case 1:
+ printf("%dus\n", BITS(l1_cap, 19, 5) * 10);
+ break;
+ case 2:
+ printf("%dus\n", BITS(l1_cap, 19, 5) * 100);
+ break;
+ default:
+ printf("<error>\n");
+ break;
+ }
+ }
+}
+
void
show_ext_caps(struct device *d)
{
@@ -526,6 +577,9 @@ show_ext_caps(struct device *d)
case PCI_EXT_CAP_ID_LTR:
cap_ltr(d, where);
break;
+ case PCI_EXT_CAP_ID_L1PM:
+ cap_l1pm(d, where);
+ break;
default:
printf("#%02x\n", id);
break;
--
1.8.0
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