More #6424 cleanups (#6442)

* Simplify logic, and more detailed debug logging
* Kill Nickel's FIFO on startup
Avoids udev/udhcpc scripts hanging when trying to open() it.

frontend/device/kobo/device.lua

@@ -359,7 +359,7 @@ function Kobo:init()
     self.input.open("/dev/input/event0") -- Various HW Buttons, Switches & Synthetic NTX events
     self.input.open("/dev/input/event1")
     -- fake_events is only used for usb plug event so far
-    -- NOTE: usb hotplug event is also available in /tmp/nickel-hardware-status
+    -- NOTE: usb hotplug event is also available in /tmp/nickel-hardware-status (... but only when Nickel is running ;p)
     self.input.open("fake_events")
 
     if not self.needsTouchScreenProbe() then

frontend/ui/network/networklistener.lua

@@ -140,18 +140,21 @@ function NetworkListener:_scheduleActivityCheck()
 
     local tx_packets = NetworkListener:_getTxPackets()
     if self._last_tx_packets then
-        -- Compute noise margin based on the current delay
+        -- Compute noise threshold based on the current delay
         local delay = self._activity_check_delay or default_network_timeout_seconds
-        local noise = delay / default_network_timeout_seconds * network_activity_noise_margin
+        local noise_threshold = delay / default_network_timeout_seconds * network_activity_noise_margin
+        local delta = tx_packets - self._last_tx_packets
         -- If there was no meaningful activity (+/- a couple packets), kill the Wi-Fi
-        if math.max(0, tx_packets - noise) <= self._last_tx_packets then
-            logger.dbg("NetworkListener: No meaningful network activity ( then:", self._last_tx_packets, "vs. now:", tx_packets, "), disabling Wi-Fi")
+        if delta <= noise_threshold then
+            logger.dbg("NetworkListener: No meaningful network activity (delta:", delta, "<= threshold:", noise_threshold, "[ then:", self._last_tx_packets, "vs. now:", tx_packets, "]) -> disabling Wi-Fi")
             keep_checking = false
             local complete_callback = function()
                 UIManager:broadcastEvent(Event:new("NetworkDisconnected"))
             end
             NetworkMgr:turnOffWifi(complete_callback)
             -- NOTE: We leave wifi_was_on as-is on purpose, we wouldn't want to break auto_restore_wifi workflows on the next start...
+        else
+            logger.dbg("NetworkListener: Significant network activity (delta:", delta, "> threshold:", noise_threshold, "[ then:", self._last_tx_packets, "vs. now:", tx_packets, "]) -> keeping Wi-Fi enabled")
         end
     end
 

platform/kobo/disable-wifi.sh

@@ -14,6 +14,7 @@ fi
 
 # NOTE: dhcpcd -k waits for the signalled process to die, but busybox's killall doesn't have a -w, --wait flag,
 #       so we have to wait for udhcpc to die ourselves...
+# NOTE: But if all is well, there *isn't* any udhcpc process or script left to begin with...
 kill_timeout=0
 while pkill -0 udhcpc; do
     # Stop waiting after 5s

platform/kobo/koreader.sh

@@ -115,6 +115,19 @@ if [ "${VIA_NICKEL}" = "true" ]; then
     #       A SIGTERM does not break anything, it'll just prevent automatic lease renewal until the time
     #       KOReader actually sets the if up itself (i.e., it'll do)...
     killall -q -TERM nickel hindenburg sickel fickel adobehost dhcpcd-dbus dhcpcd fmon
+
+    # Wait for Nickel to die... (oh, procps with killall -w, how I miss you...)
+    kill_timeout=0
+    while pkill -0 nickel; do
+        # Stop waiting after 4s
+        if [ ${kill_timeout} -ge 15 ]; then
+            break
+        fi
+        usleep 250000
+        kill_timeout=$((kill_timeout + 1))
+    done
+    # Remove Nickel's FIFO to avoid udev & udhcpc scripts hanging on open() on it...
+    rm -f /tmp/nickel-hardware-status
 fi
 
 # fallback for old fmon, KFMon and advboot users (-> if no args were passed to the script, start the FM)

platform/kobo/nickel.sh

@@ -35,6 +35,7 @@ if lsmod | grep -q sdio_wifi_pwr; then
     fi
     # NOTE: dhcpcd -k waits for the signalled process to die, but busybox's killall doesn't have a -w, --wait flag,
     #       so we have to wait for udhcpc to die ourselves...
+    # NOTE: But if all is well, there *isn't* any udhcpc process or script left to begin with...
     kill_timeout=0
     while pkill -0 udhcpc; do
         # Stop waiting after 5s

platform/kobo/release-ip.sh

@@ -15,6 +15,7 @@ fi
 
 # NOTE: dhcpcd -k waits for the signalled process to die, but busybox's killall doesn't have a -w, --wait flag,
 #       so we have to wait for udhcpc to die ourselves...
+# NOTE: But if all is well, there *isn't* any udhcpc process or script left to begin with...
 kill_timeout=0
 while pkill -0 udhcpc; do
     # Stop waiting after 5s