drm/i915: Provide a command line option to disable display

If we can't actually determine at run-time we have a fused-off display,
provide at least an option to disable it.

v2: Move the i915.disable_display test in a separate check
    (Daniel Vetter)

Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 033c943..1d65dbd 100644 (file)
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1483,9 +1483,12 @@ static void intel_device_info_runtime_init(struct drm_device *dev)
        if (IS_VALLEYVIEW(dev))
                info->num_sprites = 2;
 
-       if (info->num_pipes > 0 &&
-           (INTEL_INFO(dev)->gen == 7 || INTEL_INFO(dev)->gen == 8) &&
-           !IS_VALLEYVIEW(dev)) {
+       if (i915.disable_display) {
+               DRM_INFO("Display disabled (module parameter)\n");
+               info->num_pipes = 0;
+       } else if (info->num_pipes > 0 &&
+                  (INTEL_INFO(dev)->gen == 7 || INTEL_INFO(dev)->gen == 8) &&
+                  !IS_VALLEYVIEW(dev)) {
                u32 fuse_strap = I915_READ(FUSE_STRAP);
                u32 sfuse_strap = I915_READ(SFUSE_STRAP);
 

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 0580d97..9660114 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1958,6 +1958,7 @@ struct i915_params {
        bool fastboot;
        bool prefault_disable;
        bool reset;
+       bool disable_display;
 };
 extern struct i915_params i915 __read_mostly;
 

diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
index c743057..3b48258 100644 (file)
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -47,6 +47,7 @@ struct i915_params i915 __read_mostly = {
        .prefault_disable = 0,
        .reset = true,
        .invert_brightness = 0,
+       .disable_display = 0,
 };
 
 module_param_named(modeset, i915.modeset, int, 0400);
@@ -153,3 +154,6 @@ MODULE_PARM_DESC(invert_brightness,
        "report PCI device ID, subsystem vendor and subsystem device ID "
        "to dri-devel@lists.freedesktop.org, if your machine needs it. "
        "It will then be included in an upcoming module version.");
+
+module_param_named(disable_display, i915.disable_display, bool, 0600);
+MODULE_PARM_DESC(disable_display, "Disable display (default: false)");