On Mon, May 11, 2020 at 11:54:33AM +0200, Daniel Vetter wrote: > - One unfortunate thing with drm_dev_unplug is that the driver core is > very opinionated and doesn't tell you whether it's a hotunplug or a > driver unload. In the former case trying to shut down hw just wastes > time (and might hit driver bugs), in the latter case driver engineers > very much expect everything to be shut down. You can get that information at the PCI bus level with pci_dev_is_disconnected(). The flag queried by this function is set upon hot removal. Be aware however that the device is guaranteed to be unreachable if the function returns true, but the converse is NOT guaranteed, i.e. the function may return false even though the device has just gone away. Those somewhat difficult semantics are one of the reasons why some people are skeptical of the function's merits (notably Greg KH). See this LWN article for more information: https://lwn.net/Articles/767885/ (scroll down to the "Surprise removal" section) I've suggested to Greg a few years back that we should have a flag at the device level to indicate whether it's gone, not just at the bus level. That way the property could be expressed regardless of the bus used. It would facilitate the feature you're missing, that the driver core tells you whether it's a surprise removal or not. Unfortunately Greg rejected the idea. Thanks, Lukas _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
