On 13.06.2017 16:43, Thierry Reding wrote: > On Tue, May 23, 2017 at 03:14:22AM +0300, Dmitry Osipenko wrote: >> The framebuffers console fbcon_startup() increments the tegra_drm module >> 'use' refcount via try_module_get(), causing an interlock of the DRM subsys >> and the tegra_drm modules. In result, the tegra_drm module can't be unloaded >> using rmmod. >> >> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx> >> --- >> drivers/gpu/drm/tegra/fb.c | 1 - >> 1 file changed, 1 deletion(-) > > That's done on purpose because otherwise you could just rip out the > driver from under the framebuffer emulation and things would crash. > > My understanding is that the right way to unload a module is to unbind > the driver first (which will cause the framebuffer to be removed and > hence the reference to be dropped) before the rmmod. > > Thierry > Aha, interesting. I'll try the unbinding and will drop this patch from the series, thank you for the clarification. I haven't observed any crashes on a module reloading (framebuffer detached/attached just fine), maybe I was lucky then. -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
