[Intel-gfx] [PATCH] drm/i915: Do not clobber config status after a forced restore of hw state

[Daniel Vetter]

On Mon, Dec 02, 2013 at 05:39:09PM +0000, Chris Wilson wrote:
> We call intel_modeset_setup_hw_state() along two paths, driver
> load/resume and after a lid event notification. During initialisation of
> the driver, it is imperative that we reset the config state. This
> correctly sets up the initial connector statuses and prepares the
> hardware for a thorough probing. However, during a lid event, we only
> want to undo the damage caused by the bios by resetting our last known
> mode. In this cirumstance, we do not want to clobber our desired state.
> 
> In order to try and keep sanity between the config state and our own
> tracking, do the drm_mode_config_reset() first along the load/resume
> paths before reading out the hw state and apply any definite known
> corrections.
> 
> v2: "As discussed on irc I don't think we should force the connector
> state to anything here: Imo connector->status should reflect what we
> believe to be the true output connection state, whereas connector->encoder
> reflects whether this connector is wired up to a pipe. And since we no
> longer reject modeset on disconnected connectors and never nuked the pipe
> if the connector gets disconnected there's no reason for that - such policy
> is userspace's job.
> 
> This regression has been introduced in
> 
> commit 2e9388923e83bc4e2726f170a984621f1d582e77
> Author: Daniel Vetter <daniel.vetter at ffwll.ch>
> Date:   Thu Oct 11 20:08:24 2012 +0200
> 
>     drm/i915/crt: explicitly set up HOTPLUG_BITS on resume"
> so sayeth Daniel.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Daniel Vetter <daniel at ffwll.ch>
> Cc: stable at vger.kernel.org (v3.8 and later)
> Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
Picked up for -fixes, thanks for the patch.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch