drm/i915: drop alpha_support for good in favour of force_probe

It's been a long enough transition period since the DRM_I915_FORCE_PROBE
config and i915.force_probe module parameter were introduced in commit
7ef5ef5c ("drm/i915: add force_probe module parameter to replace
alpha_support"). Remove alpha support.

Cc: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Tomi Sarvela <tomi.p.sarvela@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200121103020.26494-1-jani.nikula@intel.com

drivers/gpu/drm/i915/Kconfig

@@ -42,16 +42,9 @@ config DRM_I915
 
 	  If "M" is selected, the module will be called i915.
 
-config DRM_I915_ALPHA_SUPPORT
-	bool "Enable alpha quality support for new Intel hardware by default"
-	depends on DRM_I915
-	help
-	  This option is deprecated. Use DRM_I915_FORCE_PROBE option instead.
-
 config DRM_I915_FORCE_PROBE
 	string "Force probe driver for selected new Intel hardware"
 	depends on DRM_I915
-	default "*" if DRM_I915_ALPHA_SUPPORT
 	help
 	  This is the default value for the i915.force_probe module
 	  parameter. Using the module parameter overrides this option.

drivers/gpu/drm/i915/i915_params.c

@@ -92,9 +92,6 @@ i915_param_named_unsafe(force_probe, charp, 0400,
 	"Force probe the driver for specified devices. "
 	"See CONFIG_DRM_I915_FORCE_PROBE for details.");
 
-i915_param_named_unsafe(alpha_support, bool, 0400,
-	"Deprecated. See i915.force_probe.");
-
 i915_param_named_unsafe(disable_power_well, int, 0400,
 	"Disable display power wells when possible "
 	"(-1=auto [default], 0=power wells always on, 1=power wells disabled when possible)");

drivers/gpu/drm/i915/i915_params.h

@@ -70,7 +70,6 @@ struct drm_printer;
 	param(char *, force_probe, CONFIG_DRM_I915_FORCE_PROBE, 0400) \
 	param(unsigned long, fake_lmem_start, 0, 0400) \
 	/* leave bools at the end to not create holes */ \
-	param(bool, alpha_support, IS_ENABLED(CONFIG_DRM_I915_ALPHA_SUPPORT), 0400) \
 	param(bool, enable_hangcheck, true, 0600) \
 	param(bool, prefault_disable, false, 0600) \
 	param(bool, load_detect_test, false, 0600) \

drivers/gpu/drm/i915/i915_pci.c

@@ -928,13 +928,6 @@ static bool force_probe(u16 device_id, const char *devices)
 	char *s, *p, *tok;
 	bool ret;
 
-	/* FIXME: transitional */
-	if (i915_modparams.alpha_support) {
-		DRM_INFO("i915.alpha_support is deprecated, use i915.force_probe=%04x instead\n",
-			 device_id);
-		return true;
-	}
-
 	if (!devices || !*devices)
 		return false;