Rapoo Input Devices Driver

Summary :

When using the keyboard to type, you may need to wait long for the keyboard to slowly spit words out. How can you fix keyboard input lag in Windows 10? To get rid of the slow keyboard response, you can read this post written by MiniTool to get some simple methods and have a try.

Keyboard Delay Windows 10

1. Rapoo offers a warranty to the original purchaser from an authorized retailer. Your Rapoo product is covered against manufacturing defects under the terms and conditions of this warranty for a period of 2 years from the date of the original purchase if purchased from an official retailer.
2. Then it allocates a new input device structure with inputallocatedevice and sets up input bitfields. This way the device driver tells the other parts of the input systems what it is - what events can be generated or accepted by this input device. Our example device can only generate EVKEY type events, and from those only BTN0 event code.

Driver developers are allowed to add additional drivers in the form of a filter driver or a new HID Client driver. The criteria are described below: Filters Drivers: Driver developers should ensure that their value-add driver is a filter driver and does not replace (or be used in place of) existing Windows HID drivers in the input stack.

When you use a PC, you may have encountered some problems. Among them, the lag issue is very common, which may happen on the computer itself, mouse and keyboard. In our previous posts, we have mentioned the first two cases – computer lag & mouse lag and today we will discuss keyboard delay.

Usually, when typing in Windows 10, you find the keyboard responses very slowly. Sometimes intermittent keyboard lag happens.

This is quite annoying and sometimes it may impact your work. Then, you may ask the question – why is my keyboard lagging? Simply put, Windows 10 keyboard lag can be caused by a hardware failure or software change.

While encountering the issue, you can try restarting your computer. If this doesn’t work, try these solutions below to get rid of the issue of keyboard input lag.

Windows 10 Input Lag Fix

Method 1: Run Hardware and Devices Troubleshooter

Windows 10 offers you some troubleshooters to fix some problems with computer hardware, blue screen of death, Bluetooth, etc. If you are having a problem with the keyboard, you can run the Hardware and Devices Troubleshooter to solve it. This can check for common issues and ensure any hardware or device is installed correctly on your PC.

Receive 'an error occurred while troubleshooting' message when using Windows Troubleshooters to fix some issues? Here are 8 helpful ways to fix it.

Here is how to run the troubleshooter:

1. Click the Windows log and choose Settings.
2. Go to Update & Security and choose Troubleshoot.
3. Click Hardware and Devices, then choose Run the troubleshooter.

Method 2: Adjust Filter Keys Setting

In Windows 10, there is a feature called Filter Keys. If it is enabled, it may slow down the input of brief or repeated keys and also may not notice the keystrokes that happen continuously. So, turning it off may fix the issue of keyboard input lag.

1. Head to Settings > Ease of Access.
2. Click Keyboard and turn off the Filter Keys feature.

Rapoo Input Devices Drivers

Method 3: Reinstall or Update the Keyboard Driver

Windows 10 keyboard lag can be caused by corrupted or old keyboard driver. So, trying to reinstall or update it can be a good solution.

1. Right-click the Start button and choose Device Manager.
2. Find your keyboard driver, right-click on it and choose Uninstall device to remove it or choose Update driver to update it.
3. Then follow the on-screen instructions to finish the corresponding operation.

Method 4: Run DISM

Sometimes the corruption and misconfigurations of your computer can lead to the issue - keyboard typing delay Windows 10. If that is the case, you can try the Deployment Image Servicing and Management (DISM) tool that can help fix Windows corruption errors easily.

Are you experiencing some annoying bugs or crashes when using your computer? Right now, you can try to repair Windows 10 image with DISM to fix these issues.

Here is how to do it:

1. Run Command Prompt with admin rights.

2. Input the following commands in order and type Enter after each one:

DISM /Online /Cleanup-Image /ScanHealth

DISM /Online /Cleanup-Image /CheckHealth

DISM /Online /Cleanup-Image /RestoreHealth

Bottom Line

Now, we have introduced four common methods to you to fix Windows 10 keyboard input lag. Actually, there are some other things you can do – check for hardware issues, check on the Keyboard Properties, run System Maintenance Troubleshooter, etc. Just try these methods based on your needs and hope you can easily get rid of typing delay.

1.1. The simplest example¶

Here comes a very simple example of an input device driver. The device hasjust one button and the button is accessible at i/o port BUTTON_PORT. Whenpressed or released a BUTTON_IRQ happens. The driver could look like:

1.2. What the example does¶

First it has to include the <linux/input.h> file, which interfaces to theinput subsystem. This provides all the definitions needed.

In the _init function, which is called either upon module load or whenbooting the kernel, it grabs the required resources (it should also checkfor the presence of the device).

Then it allocates a new input device structure with input_allocate_device()and sets up input bitfields. This way the device driver tells the otherparts of the input systems what it is - what events can be generated oraccepted by this input device. Our example device can only generate EV_KEYtype events, and from those only BTN_0 event code. Thus we only set thesetwo bits. We could have used:

as well, but with more than single bits the first approach tends to beshorter.

Then the example driver registers the input device structure by calling:

This adds the button_dev structure to linked lists of the input driver andcalls device handler modules _connect functions to tell them a new inputdevice has appeared. input_register_device() may sleep and therefore mustnot be called from an interrupt or with a spinlock held.

While in use, the only used function of the driver is:

which upon every interrupt from the button checks its state and reports itvia the:

call to the input system. There is no need to check whether the interruptroutine isn’t reporting two same value events (press, press for example) tothe input system, because the input_report_* functions check thatthemselves.

Then there is the:

call to tell those who receive the events that we’ve sent a complete report.This doesn’t seem important in the one button case, but is quite importantfor for example mouse movement, where you don’t want the X and Y valuesto be interpreted separately, because that’d result in a different movement.

1.3. dev->open() and dev->close()¶

In case the driver has to repeatedly poll the device, because it doesn’thave an interrupt coming from it and the polling is too expensive to be doneall the time, or if the device uses a valuable resource (eg. interrupt), itcan use the open and close callback to know when it can stop polling orrelease the interrupt and when it must resume polling or grab the interruptagain. To do that, we would add this to our example driver:

Note that input core keeps track of number of users for the device andmakes sure that dev->open() is called only when the first user connectsto the device and that dev->close() is called when the very last userdisconnects. Calls to both callbacks are serialized.

The open() callback should return a 0 in case of success or any nonzero valuein case of failure. The close() callback (which is void) must always succeed.

1.4. Inhibiting input devices¶

Inhibiting a device means ignoring input events from it. As such it is aboutmaintaining relationships with input handlers - either already existingrelationships, or relationships to be established while the device is ininhibited state.

If a device is inhibited, no input handler will receive events from it.

The fact that nobody wants events from the device is exploited further, bycalling device’s close() (if there are users) and open() (if there are users) oninhibit and uninhibit operations, respectively. Indeed, the meaning of close()is to stop providing events to the input core and that of open() is to startproviding events to the input core.

Calling the device’s close() method on inhibit (if there are users) allows thedriver to save power. Either by directly powering down the device or byreleasing the runtime-pm reference it got in open() when the driver is usingruntime-pm.

Inhibiting and uninhibiting are orthogonal to opening and closing the device byinput handlers. Userspace might want to inhibit a device in anticipation beforeany handler is positively matched against it.

Inhibiting and uninhibiting are orthogonal to device’s being a wakeup source,too. Being a wakeup source plays a role when the system is sleeping, not whenthe system is operating. How drivers should program their interaction betweeninhibiting, sleeping and being a wakeup source is driver-specific.

Taking the analogy with the network devices - bringing a network interface downdoesn’t mean that it should be impossible be wake the system up on LAN throughthis interface. So, there may be input drivers which should be considered wakeupsources even when inhibited. Actually, in many I2C input devices their interruptis declared a wakeup interrupt and its handling happens in driver’s core, whichis not aware of input-specific inhibit (nor should it be). Composite devicescontaining several interfaces can be inhibited on a per-interface basis and e.g.inhibiting one interface shouldn’t affect the device’s capability of being awakeup source.

If a device is to be considered a wakeup source while inhibited, special caremust be taken when programming its suspend(), as it might need to call device’sopen(). Depending on what close() means for the device in question, notopening() it before going to sleep might make it impossible to provide anywakeup events. The device is going to sleep anyway.

1.5. Basic event types¶

The most simple event type is EV_KEY, which is used for keys and buttons.It’s reported to the input system via:

See uapi/linux/input-event-codes.h for the allowable values of code (from 0 toKEY_MAX). Value is interpreted as a truth value, ie any nonzero value means keypressed, zero value means key released. The input code generates events onlyin case the value is different from before.

In addition to EV_KEY, there are two more basic event types: EV_REL andEV_ABS. They are used for relative and absolute values supplied by thedevice. A relative value may be for example a mouse movement in the X axis.The mouse reports it as a relative difference from the last position,because it doesn’t have any absolute coordinate system to work in. Absoluteevents are namely for joysticks and digitizers - devices that do work in anabsolute coordinate systems.

Having the device report EV_REL buttons is as simple as with EV_KEY, simplyset the corresponding bits and call the:

Rapoo Input Devices Driver Download

function. Events are generated only for nonzero value.

However EV_ABS requires a little special care. Before callinginput_register_device, you have to fill additional fields in the input_devstruct for each absolute axis your device has. If our button device had alsothe ABS_X axis:

Or, you can just say:

This setting would be appropriate for a joystick X axis, with the minimum of0, maximum of 255 (which the joystick must be able to reach, no problem ifit sometimes reports more, but it must be able to always reach the min andmax values), with noise in the data up to +- 4, and with a center flatposition of size 8.

If you don’t need absfuzz and absflat, you can set them to zero, which meanthat the thing is precise and always returns to exactly the center position(if it has any).

Rapoo Input Devices Driver Free

1.6. BITS_TO_LONGS(), BIT_WORD(), BIT_MASK()¶

These three macros from bitops.h help some bitfield computations:

1.7. The id* and name fields¶

The dev->name should be set before registering the input device by the inputdevice driver. It’s a string like ‘Generic button device’ containing auser friendly name of the device.

The id* fields contain the bus ID (PCI, USB, …), vendor ID and device IDof the device. The bus IDs are defined in input.h. The vendor and device idsare defined in pci_ids.h, usb_ids.h and similar include files. These fieldsshould be set by the input device driver before registering it.

The idtype field can be used for specific information for the input devicedriver.

The id and name fields can be passed to userland via the evdev interface.

1.8. The keycode, keycodemax, keycodesize fields¶

These three fields should be used by input devices that have dense keymaps.The keycode is an array used to map from scancodes to input system keycodes.The keycode max should contain the size of the array and keycodesize thesize of each entry in it (in bytes).

Userspace can query and alter current scancode to keycode mappings usingEVIOCGKEYCODE and EVIOCSKEYCODE ioctls on corresponding evdev interface.When a device has all 3 aforementioned fields filled in, the driver mayrely on kernel’s default implementation of setting and querying keycodemappings.

1.9. dev->getkeycode() and dev->setkeycode()¶

getkeycode() and setkeycode() callbacks allow drivers to override defaultkeycode/keycodesize/keycodemax mapping mechanism provided by input coreand implement sparse keycode maps.

1.10. Key autorepeat¶

… is simple. It is handled by the input.c module. Hardware autorepeat isnot used, because it’s not present in many devices and even where it ispresent, it is broken sometimes (at keyboards: Toshiba notebooks). To enableautorepeat for your device, just set EV_REP in dev->evbit. All will behandled by the input system.

1.11. Other event types, handling output events¶

The other event types up to now are:

Rapoo Input Devices Driver

• EV_LED - used for the keyboard LEDs.
• EV_SND - used for keyboard beeps.

Rapoo Input Devices Driver Update

They are very similar to for example key events, but they go in the otherdirection - from the system to the input device driver. If your input devicedriver can handle these events, it has to set the respective bits in evbit,and also the callback routine:

This callback routine can be called from an interrupt or a BH (although thatisn’t a rule), and thus must not sleep, and must not take too long to finish.