0022-skip-not-present-ACPI-devices.patch

From 9380d230e9e307c9fe81a777eb7a421b39e47698 Mon Sep 17 00:00:00 2001
From: Auke Kok <auke-jan.h.kok@intel.com>
Date: Fri, 14 Jul 2017 11:33:26 -0700
Subject: [PATCH 22/38] skip not-present ACPI devices

Xen and older Qemu expose a boatload (253) ACPI devices to the guest
that are not present; these show up in sysfs but there's nothing
meaningful one can do with them.

This patch will have udev skip these devices to save the 100ms+
boot time
---
 src/libsystemd/sd-device/device-enumerator.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/src/libsystemd/sd-device/device-enumerator.c b/src/libsystemd/sd-device/device-enumerator.c
index 39f769c35c..38734e0145 100644
--- a/src/libsystemd/sd-device/device-enumerator.c
+++ b/src/libsystemd/sd-device/device-enumerator.c
@@ -665,6 +665,22 @@ static bool relevant_sysfs_subdir(const struct dirent *de) {
         return IN_SET(de->d_type, DT_DIR, DT_LNK);
 }
 
+static int acpi_status_disabled(char *sysfspath) {
+        FILE *file;
+        unsigned int i;
+        char newpath[4096];
+        char line[128];
+        sprintf(newpath, "%s/status", sysfspath);
+        file = fopen(newpath, "r");
+        if (!file)
+                return 0;
+        fclose(file);
+
+        if (strstr(sysfspath, "acpi") && strstr(sysfspath, "device:"))
+                return 1;
+        return 0;
+}
+
 static int enumerator_scan_dir_and_add_devices(
                 sd_device_enumerator *enumerator,
                 const char *basedir,
@@ -703,6 +719,9 @@ static int enumerator_scan_dir_and_add_devices(
 
                 (void) sprintf(syspath, "%s%s", path, de->d_name);
 
+                if (acpi_status_disabled(syspath))
+                        continue;
+
                 k = sd_device_new_from_syspath(&device, syspath);
                 if (k < 0) {
                         if (k != -ENODEV)
-- 
2.36.1