Fixing Low Pen Report Rate On Surface Pro 7 (Linux)

Hey everyone! Are you experiencing a frustratingly low pen report rate on your Microsoft Surface Pro 7 while running Linux? Specifically, is your stylus locked at an unstable average of around 52Hz, causing jagged lines and poor tracking when you're trying to draw or write quickly? Don't worry, you're not alone, and we're here to dive deep into this issue and explore potential solutions. This article will guide you through understanding the problem, diagnosing the cause, and implementing fixes to get your Surface Pro 7 pen working smoothly on Linux.

Understanding the Low Pen Report Rate Issue

First off, let's define what we mean by "pen report rate." Simply put, it's how many times per second your stylus communicates its position to your device. A higher report rate translates to smoother, more accurate lines and a more responsive drawing experience. When the report rate is low, like the 52Hz we're seeing here, the input lag becomes noticeable, and your strokes can appear choppy and imprecise. This makes detailed work, like drawing or handwriting, incredibly frustrating. A stable report rate, ideally above 120Hz, is what we should be aiming for to ensure a fluid user experience.

This problem seems to be specific to the IPTS (Integrated Pen and Touch System) stylus driver stack on Linux. Users have reported that other input devices, such as USB mice, operate at their expected high report rates (over 120Hz), which rules out a general system performance issue. Furthermore, testing the pen on the same Surface Pro 7 hardware running Windows confirms that the pen is indeed capable of a stable report rate exceeding 120Hz. This strongly suggests that the problem lies within the Linux driver itself, not the pen or the Surface Pro 7's hardware.

So, if you are experiencing low pen report rates on your Surface Pro 7, especially while using it for creative tasks like drawing or note-taking, you're in the right place. We're going to explore the steps you can take to diagnose this issue and hopefully get your stylus performing as it should.

Diagnosing the Problem: Is It Really the Pen Report Rate?

Before we jump into potential fixes, it's crucial to confirm that the low pen report rate is indeed the culprit behind your stylus woes. We need to gather some data to be sure. One effective way to measure the pen report rate is using a tool called evhz. This handy utility monitors input events and reports the frequency at which they occur for different input devices connected to your system. To accurately diagnose this, you need to install and run evhz on your Linux system.

Steps to Reproduce and Measure the Report Rate

1. Boot into your Linux session on your Surface Pro 7.
2. Open a terminal and navigate to the directory where you have the evhz tool.
3. Run the evhz tool.
4. Observe the output for the IPTSD Virtual Stylus device. You should see the latest and average report rates being displayed.
5. Use your stylus to draw or write on the screen while monitoring the report rate.

Ideally, the report rate for the IPTSD Virtual Stylus should be stable and above 120Hz. If you're seeing values consistently around 52Hz or lower, and especially if the rate fluctuates significantly, you've likely confirmed the low pen report rate issue. To further confirm this, compare the stylus report rate with that of another input device, such as a USB mouse. You should see the mouse operating at a much higher and more stable report rate, typically above 120Hz.

Remember, accurate diagnosis is the key first step. Running evhz will provide concrete data, so we can confidently move forward with troubleshooting. Once you've confirmed the low report rate, we can start exploring possible solutions.

Gathering System Information: Essential Bug Reporting

Now that we've confirmed the issue, it's time to gather detailed information about your system. This information is crucial for identifying the root cause and potentially reporting the bug to the Linux-Surface community or developers. Providing comprehensive system details will help others understand your specific setup and assist in finding a solution that works for you. To effectively address this issue, we need to delve into the specifics of your system configuration.

Key System Details to Collect

• Surface Model: Knowing the exact model of your Surface Pro 7 is essential as different models may have slight variations in hardware or driver requirements. For instance, is it an i5 or i7 version? What generation is it?
• Distribution: The Linux distribution you're using (e.g., Ubuntu, Debian, Fedora) can significantly impact driver compatibility and system behavior. Make sure to specify the exact distribution name and version.
• Kernel Version: The Linux kernel is the core of your operating system, and its version plays a vital role in hardware support. Include the complete kernel version string.
• Session Type: Are you using Wayland or X11? The display server protocol can affect input handling. Specifying your session type is important.
• iptsd Version: The iptsd service is responsible for handling input from the Surface pen and touch devices. Knowing the installed version helps identify potential bugs or compatibility issues.
• libinput Version: libinput is a library that handles input events in Linux. Its version can impact how the stylus input is interpreted.

Using a Script to Automate Information Gathering

Manually gathering all this information can be tedious and error-prone. Fortunately, the Linux-Surface community has developed a script, surface_report.sh, to automate this process. This script collects the necessary system information and formats it into a bug report that you can easily share. Let's walk through how to use it. This script is a real time-saver and ensures that all relevant details are captured accurately.

The surface_report.sh script gathers crucial system information. By running this script, you can generate a comprehensive report that includes your Surface model, Linux distribution, kernel version, session type (Wayland or X11), iptsd version, and libinput version. This information will help you troubleshoot the issue and provide valuable details if you need to seek assistance from the Linux-Surface community.

Analyzing Diagnostic Logs: Dmesg, Kernel Modules, and Libinput

With the system information gathered, let's dive into the diagnostic logs. These logs contain valuable clues about what's happening under the hood and can point us towards the source of the problem. We'll focus on three key areas: dmesg output, loaded kernel modules, and libinput device listing.

1. Dmesg Output for 'ipts'

The dmesg command displays kernel messages, which can provide insights into hardware initialization and driver behavior. We'll filter the output for messages related to ipts (Integrated Pen and Touch System) to identify any errors, warnings, or unusual activity during the pen's initialization.

Command:

dmesg | grep -i ipts

Examine the output for any lines indicating issues with the IPTS driver, such as failures to initialize, firmware errors, or unexpected behavior. Any red flags here can be critical clues.

2. Loaded 'surface' and 'ipts' Kernel Modules

Kernel modules are drivers that extend the functionality of the Linux kernel. We need to ensure that the necessary modules for Surface devices and the IPTS pen system are loaded correctly. This is a crucial step in troubleshooting. The presence (or absence) of these modules can tell us a lot.

Command:

lsmod | grep -E "surface|ipts"

The output should list modules like ipts, surface_charger, surface_battery, and others related to Surface hardware. If any expected modules are missing, it could indicate a driver installation issue or a problem with module loading.

3. Libinput List-Devices

libinput is a library that handles input events in Linux. Listing the devices recognized by libinput helps us verify that the stylus is being detected correctly and that its capabilities are being properly identified. This is important for ensuring that the system recognizes your pen and its features.

Command:

libinput list-devices

The output will show a list of input devices, including the IPTS 045E:099F Stylus. Check the device's capabilities and properties. Look for any unusual entries or incorrect settings. Notably, pay attention to the device's size and capabilities listed in the output.

Potential Solutions and Troubleshooting Steps

Alright, we've confirmed the low pen report rate issue on your Surface Pro 7, gathered system information, and analyzed diagnostic logs. Now comes the exciting part: exploring potential solutions! This is where we start actively working towards fixing the problem. Keep in mind that the best solution might vary depending on your specific setup, so be prepared to try a few different approaches.

1. Update Your System and Drivers

This might seem like a no-brainer, but it's always the first step in troubleshooting any software or hardware issue. Make sure your system is fully updated, including the kernel, drivers, and firmware. Updates often include bug fixes and performance improvements that can resolve compatibility problems. Outdated software can often be the root cause of unexpected behavior, so this is a crucial step.

2. Check iptsd Configuration

The iptsd service is responsible for handling input from the Surface pen. It's possible that the service is misconfigured or not running correctly. Check the iptsd status and configuration files to ensure everything is in order. Ensuring iptsd is running correctly is key to proper pen functionality. Restarting the service might also help.

3. Experiment with Kernel Versions

Sometimes, a specific kernel version can introduce compatibility issues with certain hardware. If you're using a custom kernel or a very recent one, try switching to a different kernel version, such as a stable release or a Linux-Surface kernel, to see if it resolves the problem. This can help isolate whether the issue is kernel-specific. Kernel compatibility is a critical aspect of hardware functionality in Linux.

4. Investigate Wayland vs. X11

The display server protocol (Wayland or X11) can sometimes affect input handling. If you're using Wayland, try switching to X11, or vice versa, to see if it makes a difference. This can help determine if the issue is related to the display server. Display server protocols handle input events differently, which can impact pen performance.

5. Consult the Linux-Surface Community

The Linux-Surface community is a valuable resource for troubleshooting Surface-specific issues. Search the forums, check the issue tracker, and ask for help. Other users may have encountered the same problem and found a solution. Collaboration within the community can lead to effective solutions. Sharing your experiences and learning from others is a powerful way to resolve issues.

Conclusion: Persistence is Key

Fixing a low pen report rate on a Surface Pro 7 running Linux can be a bit of a journey, but with persistence and a systematic approach, you can often find a solution. Remember to start with the basics, gather detailed information, analyze logs, and try potential fixes one by one. Don't hesitate to consult the Linux-Surface community for help and guidance. Getting your stylus working smoothly on Linux can significantly enhance your creative workflow and overall user experience. Keep trying, and you'll get there!

By understanding the issue, diagnosing it accurately, and systematically trying different solutions, you can overcome the low pen report rate problem and enjoy a smooth and responsive stylus experience on your Surface Pro 7 running Linux. Good luck, and happy drawing!