On Mon, Jul 29, 2013 at 2:10 PM, Eric W. Biederman ebiederm@xmission.com wrote:
Alex Deucher alexdeucher@gmail.com writes:
On Mon, Jul 29, 2013 at 11:50 AM, Eric W. Biederman ebiederm@xmission.com wrote:
Alex Deucher alexdeucher@gmail.com wrote:
On Mon, Jul 29, 2013 at 10:09 AM, Markus Trippelsdorf markus@trippelsdorf.de wrote:
On 2013.07.29 at 09:58 -0400, Alex Deucher wrote:
On Mon, Jul 29, 2013 at 3:51 AM, Markus Trippelsdorf markus@trippelsdorf.de wrote: > On my test machine Xorg doesn't start anymore when I kexec into a > 3.11.0-rc3 kernel.
With kexec, dpm doesn't get torn down properly which can result in a bad hardware state when the driver loads again. Does the attached patch help? It attempts to disable dpm at startup in case it wasn't torn down properly previously.
dpm initialization now works, but unfortunately GPU acceleration
still gets
disabled:
Stupid kexec complicates things. We need to make sure dpm is torn down before we init the rest of the GPU, but dpm needs get initialized later in the init process since it depends on certain other state from the driver. I need to think about this for a bit. I'm not sure of a good way to handle this.
You might just want to implement a shutdown method that cleans things up properly. At least as a first pass until you worry about things like kexec on panic.
Or can you not shutdown the graphics stack on reboot because of the need to display the kernels shutdown progress?
Does kexec actually call this shutdown method? The driver implements appropriate clean-up measures if it's shutdown properly.
Absoltuely. All parts of the reboot path call ->shutdown. Including kexec.
You don't get a device remove/hotunplug but unless this is a kexec on panic ->shutdown is most definitely called. Now I am talking about the device layer/pci layer shutdown method I don't know how gpu drivers are wired up. GPU land was a little strange last I looked. Hopefully it isn't so strange that there is a method named shutdown that is not wired up.
It doesn't look like the drm infrastructure has a shutdown callback. The drm drivers register a drm_driver callback struct that includes an unload callback which takes care of all the device teardown (if you unload the module for example). I don't know that it actually gets called at kexec time however. I don't know enough about how kexec works.
Markus, does everything work ok after a reboot? Is it just kexec that is a problem?
Alex