[ 125/171] drm/i915: only enable sdvo hotplug irq if needed

Greg Kroah-Hartman
2013-01-15T22:52:37Z

From: Jani Nikula <jani.nikula@intel.com>

commit fcbc50da7753b210b4442ca9abc4efbd4e481f6e upstream.

Avoid constant wakeups caused by noisy irq lines when we don't even care
about the irq. This should be particularly useful for i945g/gm where the
hotplug has been disabled:

commit 768b107e4b3be0acf6f58e914afe4f337c00932b
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Fri May 4 11:29:56 2012 +0200

drm/i915: disable sdvo hotplug on i945g/gm

v2: While at it, remove the bogus hotplug_active read, and do not mask
hotplug_active[0] before checking whether the irq is needed, per discussion
with Daniel on IRC.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=38442
Tested-by: Dominik KÃ¶ppl <dominik@devwork.org>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Julien Cristau <jcristau@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpu/drm/i915/intel_sdvo.c | 15 ++++++---------
1 file changed, 6 insertions(+), 9 deletions(-)

--- a/drivers/gpu/drm/i915/intel_sdvo.c
+++ b/drivers/gpu/drm/i915/intel_sdvo.c
@@ -2570,7 +2570,6 @@ bool intel_sdvo_init(struct drm_device *
hotplug_mask = IS_SDVOB(sdvo_reg) ?
SDVOB_HOTPLUG_INT_STATUS_I915 : SDVOC_HOTPLUG_INT_STATUS_I915;
}
- dev_priv->hotplug_supported_mask |= hotplug_mask;

drm_encoder_helper_add(&intel_encoder->base, &intel_sdvo_helper_funcs);

@@ -2578,14 +2577,6 @@ bool intel_sdvo_init(struct drm_device *
if (!intel_sdvo_get_capabilities(intel_sdvo, &intel_sdvo->caps))
goto err;

- /* Set up hotplug command - note paranoia about contents of reply.
- * We assume that the hardware is in a sane state, and only touch
- * the bits we think we understand.
- */
- intel_sdvo_get_value(intel_sdvo, SDVO_CMD_GET_ACTIVE_HOT_PLUG,
- &intel_sdvo->hotplug_active, 2);
- intel_sdvo->hotplug_active[0] &= ~0x3;
-
if (intel_sdvo_output_setup(intel_sdvo,
intel_sdvo->caps.output_flags) != true) {
DRM_DEBUG_KMS("SDVO output failed to setup on SDVO%c\n",
@@ -2593,6 +2584,12 @@ bool intel_sdvo_init(struct drm_device *
goto err;
}

+ /* Only enable the hotplug irq if we need it, to work around noisy
+ * hotplug lines.
+ */
+ if (intel_sdvo->hotplug_active[0])
+ dev_priv->hotplug_supported_mask |= hotplug_mask;
+
intel_sdvo_select_ddc_bus(dev_priv, intel_sdvo, sdvo_reg);

/* Set the input timing to the screen. Assume always input 0. */