Venkatesh Surve

These phones played music through a single bottom speaker — while a second speaker, the earpiece you hold to your ear on calls, sat unused. The hardware was already capable of stereo; the manufacturers simply hadn't wired it up in software. I did, by rewriting the Qualcomm audio routing tables and shipping the change as a Magisk module.

It began as one OnePlus 6 mod — eight versions, each fixing what the last uncovered: which channel goes where, the delay between the two speakers, calls stealing the earpiece back, bluetooth and speakerphone conflicts.

v7 was the turning point — I stopped shipping a replacement mixer and started patching the existing one. That single change turned a per-device hack into a Python patcher covering 17 flagships across OnePlus, Xiaomi, Realme, LG, Essential and Nubia, spanning the Tasha (WCD9335) and Tavil (WCD9340) codecs plus custom mixer IDs on Realme hardware that had no published mapping. I maintained the device support matrix and troubleshooting docs; two devices were adopted by outside maintainers.

This was 2018–2020. Using the earpiece as a second speaker is standard on Android phones today — back then it was a handful of devices, and none of these were among them.

The kernel is the layer that decides how a phone spends power — how fast the GPU is allowed to run, when it idles, how writes hit storage. Manufacturers lock those decisions in a shipped binary. Changing any of them means replacing the kernel, which is what this is: a full Linux source tree, built and maintained for one device.

The interesting decision was a number I chose not to reach. Competing kernels added an 810MHz turbo step to the Adreno 640 GPU, which wins a benchmark run — but the K20 Pro cools passively, and it couldn't hold that. Phones running 810MHz throttled hard after five to ten minutes and dropped frames mid-game. I added a 675MHz step instead. Marginally lower peak score, substantially better sustained performance under stress tests and long sessions. The benchmark isn't the workload.

That thermal headroom turned out to matter elsewhere: people pairing the kernel with 75Hz and 81Hz display mods needed it, because driving the panel above spec generates heat of its own.

The hard constraint was SafetyNet — Google's integrity check that banking and payment apps use to refuse modified devices. Most custom kernels break it, which makes them unusable as a daily driver. Mine passed across all 8 releases, so people could actually run it.

Then I wrote the guide teaching others to compile it for the same device — because the answer to "how did you build this" shouldn't be a private one. 35 commits, 97.3% C.

The ceiling benchmark for i7-9750H — cited on TechPowerUp as the reference for that 6-core architecture. Achieved on the MSI GL65 via -125mV core/cache undervolting in ThrottleStop, PL1/PL2 power limit removal, prochot offset tuning, and RAM overclocking. Topped both i7-9750H and GTX 1650 benchmark charts simultaneously. Power limit unlocking on this platform is uncommon and requires working around firmware-level restrictions.

Founded and captained HawkOC India to #4 in the country. Without LN2, the team built custom cooling pads with high-CFM server fans directed precisely at heatsink fins — and experimented with Peltier cooling to push below ambient. Not the standard Enthusiast league approach. The engineering went into the tooling before it went into the benchmark.