lspci: Improvements to PCIe link speed downgrade reporting

Do not report PCIe link downgrades for downstream ports.

Changed wording so that "overdriven" is reported instead of
"strange" for speeds greater than the maximum supported one.

Also report nothing instead of "ok".

Inspired by patches by Bjorn Helgaas and Matthew Wilcox.

1 files changed, 11 insertions, 8 deletions

diff --git a/ls-caps.c b/ls-caps.c
index 91acb59..79b61cd 100644
--- a/ls-caps.c
+++ b/ls-caps.c
@@ -771,13 +771,16 @@ static char *link_speed(int speed)
     }
 }
 
-static char *link_compare(int sta, int cap)
+static char *link_compare(int type, int sta, int cap)
 {
-  if (sta < cap)
-    return "downgraded";
   if (sta > cap)
-    return "strange";
-  return "ok";
+    return " (overdriven)";
+  if (sta == cap)
+    return "";
+  if ((type == PCI_EXP_TYPE_ROOT_PORT) || (type == PCI_EXP_TYPE_DOWNSTREAM) ||
+      (type == PCI_EXP_TYPE_PCIE_BRIDGE))
+    return "";
+  return " (downgraded)";
 }
 
 static char *aspm_support(int code)
@@ -850,11 +853,11 @@ static void cap_express_link(struct device *d, int where, int type)
   w = get_conf_word(d, where + PCI_EXP_LNKSTA);
   sta_speed = w & PCI_EXP_LNKSTA_SPEED;
   sta_width = (w & PCI_EXP_LNKSTA_WIDTH) >> 4;
-  printf("\t\tLnkSta:\tSpeed %s (%s), Width x%d (%s)\n",
+  printf("\t\tLnkSta:\tSpeed %s%s, Width x%d%s\n",
 	link_speed(sta_speed),
-	link_compare(sta_speed, cap_speed),
+	link_compare(type, sta_speed, cap_speed),
 	sta_width,
-	link_compare(sta_width, cap_width));
+	link_compare(type, sta_width, cap_width));
   printf("\t\t\tTrErr%c Train%c SlotClk%c DLActive%c BWMgmt%c ABWMgmt%c\n",
 	FLAG(w, PCI_EXP_LNKSTA_TR_ERR),
 	FLAG(w, PCI_EXP_LNKSTA_TRAIN),