On Fri, Sep 01, 2023 at 04:41:12PM -0700, Douglas Anderson wrote: > Based on grepping through the source code this driver appears to be > missing a call to drm_atomic_helper_shutdown() at system shutdown > time. Among other things, this means that if a panel is in use that it > won't be cleanly powered off at system shutdown time. > > The fact that we should call drm_atomic_helper_shutdown() in the case > of OS shutdown/restart comes straight out of the kernel doc "driver > instance overview" in drm_drv.c. > > This driver was fairly easy to update. The drm_device is stored in the > drvdata so we just have to make sure the drvdata is NULL whenever the > device is not bound. ... and there I think you have a misunderstanding of the driver model. Please have a look at device_unbind_cleanup() which will be called if probe fails, or when the device is removed (in other words, when it is not bound to a driver.) Also, devices which aren't bound to a driver won't have their shutdown method called (because there is no driver currently bound to that device.) So, ->probe must have completed successfully, and ->remove must not have been called for that device. So, I think that all these dev_set_drvdata(dev, NULL) that you're adding are just asking for a kernel janitor to come along later and remove them because they serve no purpose... so best not introduce them in the first place. Thanks. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!
