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.

diff --git a/ls-caps.c b/ls-caps.c
index 91acb59982ac2a32baafe9b81b584d5fdc004655..79b61cd882e57a2a92181c742f5a16400ad2185f 100644 (file)
--- 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),