On 6 August 2016 at 19:04, Daniel Stone <dan...@fooishbar.org> wrote: > Hi Tomeu, > > On 22 July 2016 at 15:10, Tomeu Vizoso <tomeu.viz...@collabora.com> wrote: >> +/** >> + * DOC: CRC ABI >> + * >> + * DRM device drivers can provide to userspace CRC information of each >> frame as >> + * it reached a given hardware component (a "source"). >> + * >> + * Userspace can control generation of CRCs in a given CRTC by writing to >> the > > s/can/must/ > > Is it worth having 'auto' as a default source perhaps?
Yup, it's the case in v4, so you just cat the data file and start getting CRCs. >> + * file dri/0/crtc-N/crc/control in debugfs, with N being the index of the >> CRTC. >> + * Accepted values are source names (which are driver-specific) and the >> "none" >> + * and "auto" keywords. "none" will disable CRC generation and "auto" will >> let >> + * the driver select a default source of frame CRCs for this CRTC. > > Is it also worth having 'connector-%s' (named as per sysfs, e.g. > connector-HDMI-A-0) as a standardised entry, for cloneable CRTCs which > have CRC control on the connector rather than the CRTC? My impression right now is that only "auto" makes sense as a standardised entry, as any explicit sources are pretty much hw-dependent so the tests will need knowledge about the hw anyway. The IGT tests already try each connector in each CRTC when looking for a setup that supports CRC capture (with the auto source). Regards, Tomeu