On 2024-09-06, Jocelyn Falempe <jfalempe@xxxxxxxxxx> wrote: >> It would be great to see a version of drm_log that only implements >> write_thread() and does not do any of its own buffering with workqueue >> and also does not need to track multiple graphic loggers at the same >> time. > > Thanks for the head-up. > I will rebase it on top of Linux-next, and adapt to the new > write_thread() API, it should be much simpler. For drm_log, your write_atomic() callback should be NULL. You only need to implement the write_thead(), device_lock(), and device_unlock() callbacks. Your device_lock()/device_unlock() callbacks probably just need to lock/unlock your mutex @drm_log_lock. device_lock() is already called when the write_thread() callback is called. So your write_thread callback really only needs to call your drm_log_draw_kmsg_record(&dclient->scanout, wctxt->outbuf, wctxt->len). Please let me know if you run into any issues. We probably should write a document "HOWTO write an NBCON console driver". John Ogness
