Comment 137 for bug 1803179

Played around a little bit more with suspend-resume cycles and HDMI connection. It seems that after a suspend-resume-glxgears cycle, I can connect and disconnect by external monitor reliably (no "Unsupported output format" message), so that behavior seems to trigger either only after boot, or randomly (and I didn't manage to trigger it again while playing around).

Moreover, after powering on my card by plugging in the monitor, power usage settles around 37W as opposed to 43W, so I might have been too hasty when comparing the power draw of my card in various states. As the discrepancy is quite a bit smaller than I have thought (37W when powered up vs 28W when DynOff with a patched SSDT9), it might be explained by the fact that in "state 2", the card is indeed fully powered, but nouveau thinks it is off, so utilization is 0%. Whereas the card in "state 1" is indeed off, hence the issue when trying to power it up.