Input: Some more followups to the input device auto-detection stuff (#11855)

Switch to a new `input.fdopen` API & wrapper so we can keep the fds opened by `fbink_input_scan` instead of closing them to re-open them right after that...

This should hopefully help on racy zForce devices that attempt to handle power management when opening/closing the device. We know this sometimes horribly fail to re-activate the IR grid (c.f., our manual activation on resume), but this apparently could also happen here (re: #11844) because of the quick succession of open->close->open.

base

@@ -1 +1 @@
-Subproject commit f9c9316709a9683406a759888090ea04098cf46b
+Subproject commit 61c05b668f0764988cc857f3a59024e35fded62b

frontend/device/input.lua

@@ -323,6 +323,29 @@ function Input.open(path, name)
     end
 end
 
+--[[--
+Wrapper for our Lua/C input module's fdopen.
+
+Note that we adhere to the "." syntax here for compatibility.
+
+The `name` argument is optional, and used for logging purposes only.
+`path` is mandatory, though!
+--]]
+function Input.fdopen(fd, path, name)
+    -- Make sure we don't open the same device twice.
+    if not Input.opened_devices[path] then
+        input.fdopen(fd)
+        -- As with input.open, it will throw on error (closing the fd first)
+        Input.opened_devices[path] = fd
+        if name then
+            logger.dbg("Kept fd", fd, "open for input device", name, "@", path)
+        else
+            logger.dbg("Kept fd", fd, "open for input device @", path)
+        end
+        return fd
+    end
+end
+
 --[[--
 Wrapper for our Lua/C input module's close.
 

frontend/device/kindle/device.lua

@@ -216,12 +216,12 @@ function Kindle:openInputDevices()
     local dev_count = ffi.new("size_t[1]")
     -- We care about: the touchscreen, a properly scaled stylus, pagination buttons, a home button and a fiveway.
     local match_mask = bit.bor(C.INPUT_TOUCHSCREEN, C.INPUT_SCALED_TABLET, C.INPUT_PAGINATION_BUTTONS, C.INPUT_HOME_BUTTON, C.INPUT_DPAD)
-    local devices = FBInkInput.fbink_input_scan(match_mask, 0, C.SCAN_ONLY, dev_count)
+    local devices = FBInkInput.fbink_input_scan(match_mask, 0, 0, dev_count)
     if devices ~= nil then
         for i = 0, tonumber(dev_count[0]) - 1 do
             local dev = devices[i]
             if dev.matched then
-                self.input.open(ffi.string(dev.path), ffi.string(dev.name))
+                self.input.fdopen(tonumber(dev.fd), ffi.string(dev.path), ffi.string(dev.name))
             end
         end
         C.free(devices)
@@ -243,12 +243,12 @@ function Kindle:openInputDevices()
     if self:hasGSensor() then
         -- i.e., we want something that reports EV_ABS:ABS_PRESSURE that isn't *also* a pen (because those are pretty much guaranteed to report pressure...).
         --       And let's add that isn't also a touchscreen to the mix, because while not true at time of writing, that's an event touchscreens sure can support...
-        devices = FBInkInput.fbink_input_scan(C.INPUT_ROTATION_EVENT, bit.bor(C.INPUT_TABLET, C.INPUT_TOUCHSCREEN), bit.bor(C.SCAN_ONLY, C.NO_RECAP), dev_count)
+        devices = FBInkInput.fbink_input_scan(C.INPUT_ROTATION_EVENT, bit.bor(C.INPUT_TABLET, C.INPUT_TOUCHSCREEN), C.NO_RECAP, dev_count)
         if devices ~= nil then
             for i = 0, tonumber(dev_count[0]) - 1 do
                 local dev = devices[i]
                 if dev.matched then
-                    self.input.open(ffi.string(dev.path), ffi.string(dev.name))
+                    self.input.fdopen(tonumber(dev.fd), ffi.string(dev.path), ffi.string(dev.name))
                 end
             end
             C.free(devices)

frontend/device/kobo/device.lua

@@ -867,7 +867,7 @@ function Kobo:init()
     -- (and technically rotation events, but we'll get it with the device that provides the buttons on NTX).
     -- We exclude keyboards to play nice with the ExternalKeyboard plugin, which will handle potential keyboards on its own.
     local match_mask = bit.bor(C.INPUT_TOUCHSCREEN, C.INPUT_TABLET, C.INPUT_POWER_BUTTON, C.INPUT_SLEEP_COVER, C.INPUT_PAGINATION_BUTTONS)
-    local devices = FBInkInput.fbink_input_scan(match_mask, C.INPUT_KEYBOARD, C.SCAN_ONLY, dev_count)
+    local devices = FBInkInput.fbink_input_scan(match_mask, C.INPUT_KEYBOARD, 0, dev_count)
     if devices ~= nil then
         for i = 0, tonumber(dev_count[0]) - 1 do
             local dev = devices[i]
@@ -875,9 +875,9 @@ function Kobo:init()
                 -- We need to single out whichever device provides pagination buttons or sleep cover events, as we'll want to tweak key repeat there...
                 -- The first one will do, as it's extremely likely to be event0, and that's pretty fairly set in stone on NTX boards.
                 if (bit.band(dev.type, C.INPUT_PAGINATION_BUTTONS) ~= 0 or bit.band(dev.type, C.INPUT_SLEEP_COVER) ~= 0) and not self.ntx_fd then
-                    self.ntx_fd = self.input.open(ffi.string(dev.path), ffi.string(dev.name))
+                    self.ntx_fd = self.input.fdopen(tonumber(dev.fd), ffi.string(dev.path), ffi.string(dev.name))
                 else
-                    self.input.open(ffi.string(dev.path), ffi.string(dev.name))
+                    self.input.fdopen(tonumber(dev.fd), ffi.string(dev.path), ffi.string(dev.name))
                 end
             end
         end

plugins/externalkeyboard.koplugin/main.lua

@@ -294,14 +294,14 @@ local function findKeyboards()
 
     local FBInkInput = ffi.load("fbink_input")
     local dev_count = ffi.new("size_t[1]")
-    local devices = FBInkInput.fbink_input_scan(C.INPUT_KEYBOARD, 0, C.SCAN_ONLY, dev_count)
+    local devices = FBInkInput.fbink_input_scan(C.INPUT_KEYBOARD, 0, 0, dev_count)
     if devices ~= nil then
         for i = 0, tonumber(dev_count[0]) - 1 do
             local dev = devices[i]
             if dev.matched then
                 -- Check if it provides a DPad, too.
                 local has_dpad = bit.band(dev.type, C.INPUT_DPAD) ~= 0
-                table.insert(keyboards, { event_path = ffi.string(dev.path), has_dpad = has_dpad })
+                table.insert(keyboards, { event_fd = tonumber(dev.fd), event_path = ffi.string(dev.path), name = ffi.string(dev.name), has_dpad = has_dpad })
             end
         end
         C.free(devices)
@@ -314,11 +314,13 @@ local function checkKeyboard(path)
     local keyboard
 
     local FBInkInput = ffi.load("fbink_input")
-    local dev = FBInkInput.fbink_input_check(path, C.INPUT_KEYBOARD, 0, C.SCAN_ONLY)
+    local dev = FBInkInput.fbink_input_check(path, C.INPUT_KEYBOARD, 0, 0)
     if dev ~= nil then
         if dev.matched then
             keyboard = {
+                event_fd = tonumber(dev.fd),
                 event_path = ffi.string(dev.path),
+                name = ffi.string(dev.name),
                 has_dpad = bit.band(dev.type, C.INPUT_DPAD) ~= 0
             }
         end
@@ -359,10 +361,10 @@ function ExternalKeyboard:setupKeyboard(data)
 
     local has_dpad_func = Device.hasDPad
 
-    logger.dbg("ExternalKeyboard:setupKeyboard", keyboard_info.event_path, "has_dpad", keyboard_info.has_dpad)
+    logger.dbg("ExternalKeyboard:setupKeyboard", keyboard_info.name, "@", keyboard_info.event_path, "- has_dpad:", keyboard_info.has_dpad)
     -- Check if we already know about this event file.
     if ExternalKeyboard.keyboard_fds[keyboard_info.event_path] == nil then
-        local ok, fd = pcall(Device.input.open, keyboard_info.event_path)
+        local ok, fd = pcall(Device.input.fdopen, keyboard_info.event_fd, keyboard_info.event_path, keyboard_info.name)
         if not ok then
             UIManager:show(InfoMessage:new{
                 text = "Error opening keyboard:\n" .. tostring(fd),
@@ -373,7 +375,7 @@ function ExternalKeyboard:setupKeyboard(data)
 
         ExternalKeyboard.keyboard_fds[keyboard_info.event_path] = fd
         ExternalKeyboard.connected_keyboards = ExternalKeyboard.connected_keyboards + 1
-        logger.dbg("ExternalKeyboard: USB keyboard", keyboard_info.event_path, "was connected; total:", ExternalKeyboard.connected_keyboards)
+        logger.dbg("ExternalKeyboard: USB keyboard", keyboard_info.name, "@", keyboard_info.event_path, "was connected; total:", ExternalKeyboard.connected_keyboards)
 
         if keyboard_info.has_dpad then
             has_dpad_func = yes