Re: [PATCH v7 2/9] drm/panic: Add a drm panic handler

From: Daniel Vetter <daniel@ffwll.ch>
To: Jocelyn Falempe <jfalempe@redhat.com>
Cc: bluescreen_avenger@verizon.net, tzimmermann@suse.de,
	javierm@redhat.com, mripard@kernel.org, gpiccoli@igalia.com,
	noralf@tronnes.org, dri-devel@lists.freedesktop.org,
	airlied@redhat.com
Subject: Re: [PATCH v7 2/9] drm/panic: Add a drm panic handler
Date: Fri, 12 Jan 2024 14:50:53 +0100	[thread overview]
Message-ID: <ZaFDvaOgjM_nGOKz@phenom.ffwll.local> (raw)
In-Reply-To: <20240104160301.185915-3-jfalempe@redhat.com>

On Thu, Jan 04, 2024 at 05:00:46PM +0100, Jocelyn Falempe wrote:
> +/**
> + * drm_panic_init() - Initialize drm-panic subsystem
> + *
> + * register the panic notifier
> + */
> +void drm_panic_init(void)
> +{
> +	atomic_notifier_chain_register(&panic_notifier_list,
> +				       &drm_panic_notifier);

Ok I've found another one after checking core panic code. This is the
wrong hook, we want to be a sttruct kmsg_dumper and use
kmsg_dump_register. And again once for each drm_panic_device so that we
can rely on core locking, as I've explained in the other reply.

Also because it trashes buffers from userspace I think by default we want
to only dump on panic, so KMS_DUMP_PANIC.
-Sima
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch