Linux Audio Miniconf 2018 report

The audio miniconference was held on the 21st in the offices of Cirrus Logic in Edinburgh with 15 attendees from across the industry including userspace and kernel developers, with people from several OS vendors and a range of silicon companies.

2018 Linux Audio Miniconference

As in previous years we’re trying to organize an audio miniconference so we can get together and talk through issues, especially design decisons, face to face. This year’s event will be held on Sunday October 21st in Edinburgh, the day before ELC Europe starts there. Cirrus Logic have generously offered to host this in their Edinburgh office: 7B […]

Bronica Motor Drive SQ-i

I recently got a Bronica SQ-Ai medium format film camera which came with the Motor Drive SQ-i. Since I couldn’t find any documentation at all about it on the internet and had to figure it out for myself I figured I’d put what I figured out here. Hopefully this will help the next person trying […]

OpenTAC sprint

This weekend Toby Churchill kindly hosted a hacking weekend for OpenTAC – myself, Michael Grzeschik, Steve McIntyre and Andy Simpkins got together to bring up the remaining bits of the hardware on the current board revision and get some of the low level tooling like production flashing for the FTDI serial ports on the board up […]

Expedient ABIs

The biggest change we’ve seen in the Linux kernel for ARM over the past few years has been the transition to providing descriptions of the hardware in systems via device tree. This splits out the description of the devices in the system that can’t be automatically enumerated from the kernel into a separate binary instead […]

Performance problems

Just over a year ago I implemented an optimization to the SPI core code in Linux that avoids some needless context switches to a worker thread in the main data path that most clients use. This was really nice, it was simple to do but saved a bunch of work for most drivers using SPI and made things […]

Maintaining your email

One of the difficulties of being a kernel maintainer for a busy subsystem is that you will often end up getting a lot of mail that requires reading and handling which in turn requires sending a lot of mail out in reply. Some of that requires thought and careful consideration but a lot of it […]

Maximising the efficiency of chained regulators

Linux v4.4 will include a cool new feature contributed by Sascha Hauer of Pengutronix which propagates voltages set on a regulator to the regulators that supply it (taking into account the minimum headroom that the child regulator needs). The original reason for implementing it was to allow us to set voltages through simple unregulated power […]

Flashing an AT91SAM9G20-EK from bare metal

Since I just had cause to do this and it was harder than it needed to be due to bitrot in the public documentation I could find I thought I’d write up how to get a modern bootloader onto older Atmel boards. These instructions are written for the AT91SAM9G20-EK though they should also apply to […]

Acer Aspire E11

Recently I was in Seoul in the middle of three weeks of travel and my laptop died on me.  Since I had some work that needed doing fairly urgently I took myself over to Yongsan Electronics Market and got myself a cheap replacement to tide myself over. What I ended up with was an Acer Aspire […]