On Thu, Feb 02, 2017 at 10:25:44AM -0700, Shuah Khan wrote: > On 02/02/2017 01:32 AM, Jani Nikula wrote: > > On Thu, 02 Feb 2017, Shuah Khan <shuahkh@xxxxxxxxxxxxxxx> wrote: > >> Change drm_helper_probe_single_connector_modes() to print an error to > >> report connector disconnected status instead of a debug message. > >> > >> When this condition occurs, application doesn't know the real error and > >> reports it as driver lacking support for mode setting. Change it to an > >> error to make it easier to debug. > > > > Please explain what makes this condition an error. Connectors get > > connected and disconnected, business as usual, why should this be an > > error? > > > > BR, > > Jani. > > Disconnecting connector itself isn't an error. When user-space tries > to access it, it would be useful to report the status that the connector > is disconnected. > > I use embedded system(s) that don't like it when HDMI is hot added or > removed. Also, because of return power, it is safer to disconnect HDMI > and then apply power to the board. It chased a few libdrm and user-space > dead ends before I enabled drm debug and was able to fix the real issue, > which is a disconnected cable. > > User-space prints rather confusing messages as it doesn't really know > the disconnected status as it isn't returned to it. > > I figured it might be a good idea to at least print a message and this can > be a notice or info instead of an error. I do think its is worth while in > some cases. This sounds like a very specific use-case you have here, and it can easily be supported by a small deamon in userspace (only on debug builds ofc) that tell you that someone unplugged the screen when it shouldn't have been. Because upstream runs also on non-embedded systems, where unplugging is normal, and we definitely don't want to spam dmesg. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
