From ee122eefefa2cdf29c0c2ed104a6bb9957ad5ae2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marek=20Marczykowski-G=C3=B3recki?=
 <marmarek@invisiblethingslab.com>
Date: Mon, 22 Jan 2018 19:14:07 +0100
Subject: [PATCH] Detach all drivers from PCI devices before suspend

The most common thing to fix S3 sleep is to unload PCI devices drivers
before suspend. Instead of having every user figuring out what drivers
needs to be blacklisted, detach all drivers from actual PCI devices.
Exclude qemu emulated devices.

Fixes QubesOS/qubes-issues#3486
---
 qubes-rpc/prepare-suspend | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/qubes-rpc/prepare-suspend b/qubes-rpc/prepare-suspend
index 6200705..f96a2c0 100755
--- a/qubes-rpc/prepare-suspend
+++ b/qubes-rpc/prepare-suspend
@@ -34,6 +34,24 @@ if [ x"$action" = x"suspend" ]; then
         fi
         ip l s "$intf" down
     done
+
+    # detach all drivers from PCI devices (the real ones, not emulated by qemu)
+    echo -n > /var/run/qubes-suspend-pci-devs-detached
+    for dev_path in /sys/bus/pci/devices/*; do
+        # skip qemu emulated devs
+        subsystem_vendor=$(cat "$dev_path/subsystem_vendor")
+        if [ "$subsystem_vendor" = "0x1af4" ] || [ "$subsystem_vendor" = "0x5853" ]; then
+            continue
+        fi
+        if ! [ -e "$dev_path/driver" ]; then
+            continue
+        fi
+        bdf=$(basename "$dev_path")
+        driver_path=$(readlink -f "$dev_path/driver")
+        echo "$bdf" > "$driver_path/unbind"
+        echo "$bdf $driver_path" >> /var/run/qubes-suspend-pci-devs-detached
+    done
+
     LOADED_MODULES=""
     for mod in $MODULES_BLACKLIST; do
         if lsmod |grep -q "$mod"; then
@@ -48,6 +66,12 @@ else
         modprobe "$mod"
     done
     rm -f /var/run/qubes-suspend-modules-loaded
+
+    while read -r dev driver_path; do
+        echo "$dev" > "$driver_path/bind"
+    done < /var/run/qubes-suspend-pci-devs-detached
+    rm -f /var/run/qubes-suspend-pci-devs-detached
+
     if qsvc network-manager ; then
         dbus-send --system --print-reply          \
             --dest=org.freedesktop.NetworkManager \