Messages in this thread | | | Date | Mon, 29 Jun 2015 10:09:14 +0200 | From | Borislav Petkov <> | Subject | Re: drm/mgag200: doesn't work in panic context |
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On Sat, Jun 27, 2015 at 07:56:19PM +0200, Daniel Vetter wrote:
<snip very useful explanation for !GPU people>
> Which could all happen very much after the kernel made it's dying > sigh. Display hw has long stopped being this simple and display > drivers also.
Thanks for the explanation. I was fearing that it would go in such direction though. :\ Oh well.
So there are two observations to be ventured here:
* there's still no robust and simple way to save/show oops messages on laptops. When a laptop crashes and the user has only this one machine, catching the oops can be a serious PITA. Laptop most likely doesn't have serial, modeset is hard to do, as you explained, and saving it into persistent storage (UEFI) might brick it in some cases or whatever the firmware will do to it. I guess we can keep wishing here for something better.
* The server aspect might not really need GPU modesetting IMHO because realistically, servers have serial so the oops can go out there. Which begs the other question:
Shouldn't drm_fb_helper_panic() and that path below it simply be removed?
I mean, if it needs to do all that hw-reconf on the panic path and if that reconfiguration is not completely reliable, maybe we shouldn't do it all?
This way, we will basically remain as quiet as possible in order not to muddle the system unreasonably when we're about to die and the only thing we want to catch is an oops or maybe kexec the crash kernel...
Oops will go out on serial anyway and server will kexec - GPU/fb stuff doesn't do anything. Yes, no?
Hmmm.
-- Regards/Gruss, Boris.
ECO tip #101: Trim your mails when you reply. --
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