13 Jun
2017
13 Jun
'17
1:43 p.m.
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@gmail.com
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