[PATCH] drm/i915: Enable fastboot by default on VLV and CHV

[Hans de Goede]

We really want to have fastboot enabled by default to avoid an ugly
modeset during boot.

Currently we are enabling fastboot by default on gen9+ (Skylake and newer).
The intention is to enable it on older generations after it has seen more
testing on gen9+.

VLV and CHV devices are still being sold in stores today, as such it is
desirable to also enable fastboot by default on these now.

I've extensively tested fastboot=1 support on over 50 different
Bay- and Cherry-Trail devices. Testing DSI and eDP panels as well as
HDMI output (and even DP over Type-C on one device).

All 50 devices work fine with fastboot=1. On 2 devices their DSI panel
turns black as soon as the i915 driver loads when fastboot=0, so having
fastboot enabled is required for these 2 to work properly (for lack of
a better fix).

Signed-off-by: Hans de Goede <hdegoede at redhat.com>
---
 drivers/gpu/drm/i915/intel_display.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index d756d7358292..0ff42a38023c 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -11672,7 +11672,15 @@ static bool fastboot_enabled(struct drm_i915_private *dev_priv)
 		return i915_modparams.fastboot;
 
 	/* Enable fastboot by default on Skylake and newer */
-	return INTEL_GEN(dev_priv) >= 9;
+	if (INTEL_GEN(dev_priv) >= 9)
+		return true;
+
+	/* Enable fastboot by default on VLV and CHV */
+	if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
+		return true;
+
+	/* Disabled by default on all others */
+	return false;
 }
 
 static bool
-- 
2.20.1