drm/i915: provide module parameter description

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Keith Packard <keithp@keithp.com>
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index ef5cf03..ce045a8 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -39,39 +39,68 @@
 
 static int i915_modeset __read_mostly = -1;
 module_param_named(modeset, i915_modeset, int, 0400);
+MODULE_PARM_DESC(modeset,
+		"Use kernel modesetting [KMS] (0=DRM_I915_KMS from .config, "
+		"1=on, -1=force vga console preference [default])");
 
 unsigned int i915_fbpercrtc __always_unused = 0;
 module_param_named(fbpercrtc, i915_fbpercrtc, int, 0400);
 
 int i915_panel_ignore_lid __read_mostly = 0;
 module_param_named(panel_ignore_lid, i915_panel_ignore_lid, int, 0600);
+MODULE_PARM_DESC(panel_ignore_lid,
+		"Override lid status (0=autodetect [default], 1=lid open, "
+		"-1=lid closed)");
 
 unsigned int i915_powersave __read_mostly = 1;
 module_param_named(powersave, i915_powersave, int, 0600);
+MODULE_PARM_DESC(powersave,
+		"Enable powersavings, fbc, downclocking, etc. (default: true)");
 
 unsigned int i915_semaphores __read_mostly = 0;
 module_param_named(semaphores, i915_semaphores, int, 0600);
+MODULE_PARM_DESC(semaphores,
+		"Use semaphores for inter-ring sync (default: false)");
 
 unsigned int i915_enable_rc6 __read_mostly = 0;
 module_param_named(i915_enable_rc6, i915_enable_rc6, int, 0600);
+MODULE_PARM_DESC(i915_enable_rc6,
+		"Enable power-saving render C-state 6 (default: true)");
 
 unsigned int i915_enable_fbc __read_mostly = 1;
 module_param_named(i915_enable_fbc, i915_enable_fbc, int, 0600);
+MODULE_PARM_DESC(i915_enable_fbc,
+		"Enable frame buffer compression for power savings "
+		"(default: false)");
 
 unsigned int i915_lvds_downclock __read_mostly = 0;
 module_param_named(lvds_downclock, i915_lvds_downclock, int, 0400);
+MODULE_PARM_DESC(lvds_downclock,
+		"Use panel (LVDS/eDP) downclocking for power savings "
+		"(default: false)");
 
 unsigned int i915_panel_use_ssc __read_mostly = 1;
 module_param_named(lvds_use_ssc, i915_panel_use_ssc, int, 0600);
+MODULE_PARM_DESC(lvds_use_ssc,
+		"Use Spread Spectrum Clock with panels [LVDS/eDP] "
+		"(default: true)");
 
 int i915_vbt_sdvo_panel_type __read_mostly = -1;
 module_param_named(vbt_sdvo_panel_type, i915_vbt_sdvo_panel_type, int, 0600);
+MODULE_PARM_DESC(vbt_sdvo_panel_type,
+		"Override selection of SDVO panel mode in the VBT "
+		"(default: auto)");
 
 static bool i915_try_reset __read_mostly = true;
 module_param_named(reset, i915_try_reset, bool, 0600);
+MODULE_PARM_DESC(reset, "Attempt GPU resets (default: true)");
 
 bool i915_enable_hangcheck __read_mostly = true;
 module_param_named(enable_hangcheck, i915_enable_hangcheck, bool, 0644);
+MODULE_PARM_DESC(enable_hangcheck,
+		"Periodically check GPU activity for detecting hangs. "
+		"WARNING: Disabling this can cause system wide hangs. "
+		"(default: true)");
 
 static struct drm_driver driver;
 extern int intel_agp_enabled;