drm/i915: add fbc enable flag, but disable by default

FBC has too many corner cases that we don't currently deal with, so
disable it by default so we can enable more important features like RC6,
which conflicts in some configurations.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=31742
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 183eaac8980a3f6a31bb4c9027695eed2a59caa6..51c2257b11e6d7cfb990b6a667b8fa00e59dd92e 100644 (file)
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1065,6 +1065,9 @@ static int i915_fbc_status(struct seq_file *m, void *unused)
                case FBC_MULTIPLE_PIPES:
                        seq_printf(m, "multiple pipes are enabled");
                        break;
+               case FBC_MODULE_PARAM:
+                       seq_printf(m, "disabled per module param (default off)");
+                       break;
                default:
                        seq_printf(m, "unknown reason");
                }

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 8c4fcbb8a4cb328b52d4f58104d3b7501289eada..4c9e92f8abc2f1cd58cc4cd91216ca4563c3d9e2 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -55,6 +55,9 @@ module_param_named(semaphores, i915_semaphores, int, 0600);
 unsigned int i915_enable_rc6 = 0;
 module_param_named(i915_enable_rc6, i915_enable_rc6, int, 0600);
 
+unsigned int i915_enable_fbc = 0;
+module_param_named(i915_enable_fbc, i915_enable_fbc, int, 0600);
+
 unsigned int i915_lvds_downclock = 0;
 module_param_named(lvds_downclock, i915_lvds_downclock, int, 0400);
 
@@ -169,7 +172,7 @@ static const struct intel_device_info intel_ironlake_d_info = {
 static const struct intel_device_info intel_ironlake_m_info = {
        .gen = 5, .is_mobile = 1,
        .need_gfx_hws = 1, .has_hotplug = 1,
-       .has_fbc = 0, /* disabled due to buggy hardware */
+       .has_fbc = 1,
        .has_bsd_ring = 1,
 };
 

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 3a1c277180650995c18fc9c3de7fb1ff16a222ca..ee660355ae6839839713ae3ecca369cf60f81a6d 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -250,6 +250,7 @@ enum no_fbc_reason {
        FBC_BAD_PLANE, /* fbc not supported on plane */
        FBC_NOT_TILED, /* buffer not tiled */
        FBC_MULTIPLE_PIPES, /* more than one pipe active */
+       FBC_MODULE_PARAM,
 };
 
 enum intel_pch {
@@ -995,6 +996,7 @@ extern unsigned int i915_lvds_downclock;
 extern unsigned int i915_panel_use_ssc;
 extern int i915_vbt_sdvo_panel_type;
 extern unsigned int i915_enable_rc6;
+extern unsigned int i915_enable_fbc;
 
 extern int i915_suspend(struct drm_device *dev, pm_message_t state);
 extern int i915_resume(struct drm_device *dev);

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 5ec74df2627e15781de240069b9d9705d18a23e6..81ad654f354475bc68cc294f8002350eb69ae313 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1731,6 +1731,11 @@ static void intel_update_fbc(struct drm_device *dev)
        intel_fb = to_intel_framebuffer(fb);
        obj = intel_fb->obj;
 
+       if (!i915_enable_fbc) {
+               DRM_DEBUG_KMS("fbc disabled per module param (default off)\n");
+               dev_priv->no_fbc_reason = FBC_MODULE_PARAM;
+               goto out_disable;
+       }
        if (intel_fb->obj->base.size > dev_priv->cfb_size) {
                DRM_DEBUG_KMS("framebuffer too large, disabling "
                              "compression\n");