On 5/28/19 9:53 AM, Dariusz Marcinkiewicz wrote: > On Fri, May 24, 2019 at 11:21 AM Hans Verkuil <hverkuil@xxxxxxxxx> wrote: >> >> Hi Dariusz, >> >> I did some more testing with the Khadas VIM2 and found another problem, >> something that will, unfortunately, require some redesign. >> > ... >> >> The other problem is in the CEC driver: it creates the CEC device as >> soon as the HDMI device is found (cec_notifier_parse_hdmi_phandle). >> >> But that doesn't mean that the HDMI device also had registered itself >> as a CEC notifier. >> >> Until now that never mattered: as long as the HDMI device was found >> the CEC adapter would function fine, it would just have no physical >> address until so notified by the HDMI device once it registered its >> CEC notifier. >> >> But if we want to have valid connector info during the lifetime of >> the CEC adapter, then this no longer works. >> >> I'm not entirely sure how to handle this. >> >> Another issue here is that when the HDMI driver removes the notifier, >> then it should also zero the connector info. Remember that both the >> HDMI and the CEC drivers can be loaded and unloaded independently from >> one another. >> > Given all of the above, what do you think about coming back to the v1 > of the patch, where a connector info could be set on an adapter at any > time and an event was used to notify userland when that happened? That > approach seems to cover all the scenarios mentioned above. That's just hiding the real problems :-) I hope to spend some time on CEC tomorrow and I'll get back to you then. Regards, Hans
