drm/i915: Break encoder->crtc link separately in intel_sanitize_crtc()

Depending on the SDVO output_flags SDVO may have multiple connectors
linking to the same encoder (in intel_connector->encoder->base).
Only one of those connectors should be active (ie link to the encoder
thru drm_connector->encoder).
If intel_connector_break_all_links() is called from intel_sanitize_crtc()
we may break the crtc connection of an encoder thru an inactive connector
in which case intel_connector_break_all_links() will not be called again
for the active connector if this happens to come later in the list due to:
    if (connector->encoder->base.crtc != &crtc->base)
                                 continue;
in intel_sanitize_crtc().
This will however leave the drm_connector->encoder linkage for this
active connector in place. Subsequently this will cause multiple
warnings in intel_connector_check_state() to trigger and the driver
will eventually die in drm_encoder_crtc_ok() (because of crtc == NULL).

To avoid this remove intel_connector_break_all_links() and move its
code to its two calling functions: intel_sanitize_crtc() and
intel_sanitize_encoder().
This allows to implement the link breaking more flexibly matching
the surrounding code: ie. in intel_sanitize_crtc() we can break the
crtc link separatly after the links to the encoders have been
broken which avoids above problem.

This regression has been introduced in:

commit 2492935248
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Mon Jul 2 20:28:59 2012 +0200

    drm/i915: read out the modeset hw state at load and resume time

so goes back to the very beginning of the modeset rework.

v2: This patch takes care of the concernes voiced by Chris Wilson
and Daniel Vetter that only breaking links if the drm_connector
is linked to an encoder may miss some links.
v3: move all encoder handling to encoder loop as suggested by
Daniel Vetter.

Signed-off-by: Egbert Eich <eich@suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@vger.kernel.org
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
This commit is contained in:
Egbert Eich 2014-04-25 10:56:22 +02:00 committed by Jani Nikula
parent 78f2975eec
commit 7f1950fbb9
1 changed files with 14 additions and 12 deletions

View File

@ -11395,15 +11395,6 @@ void intel_modeset_init(struct drm_device *dev)
}
}
static void
intel_connector_break_all_links(struct intel_connector *connector)
{
connector->base.dpms = DRM_MODE_DPMS_OFF;
connector->base.encoder = NULL;
connector->encoder->connectors_active = false;
connector->encoder->base.crtc = NULL;
}
static void intel_enable_pipe_a(struct drm_device *dev)
{
struct intel_connector *connector;
@ -11485,8 +11476,17 @@ static void intel_sanitize_crtc(struct intel_crtc *crtc)
if (connector->encoder->base.crtc != &crtc->base)
continue;
intel_connector_break_all_links(connector);
connector->base.dpms = DRM_MODE_DPMS_OFF;
connector->base.encoder = NULL;
}
/* multiple connectors may have the same encoder:
* handle them and break crtc link separately */
list_for_each_entry(connector, &dev->mode_config.connector_list,
base.head)
if (connector->encoder->base.crtc == &crtc->base) {
connector->encoder->base.crtc = NULL;
connector->encoder->connectors_active = false;
}
WARN_ON(crtc->active);
crtc->base.enabled = false;
@ -11568,6 +11568,8 @@ static void intel_sanitize_encoder(struct intel_encoder *encoder)
drm_get_encoder_name(&encoder->base));
encoder->disable(encoder);
}
encoder->base.crtc = NULL;
encoder->connectors_active = false;
/* Inconsistent output/port/pipe state happens presumably due to
* a bug in one of the get_hw_state functions. Or someplace else
@ -11578,8 +11580,8 @@ static void intel_sanitize_encoder(struct intel_encoder *encoder)
base.head) {
if (connector->encoder != encoder)
continue;
intel_connector_break_all_links(connector);
connector->base.dpms = DRM_MODE_DPMS_OFF;
connector->base.encoder = NULL;
}
}
/* Enabled encoders without active connectors will be fixed in