[PATCH 4.4 239/241] drm/gma500/cdv: Check vbt config bits when detecting lvds panels

From: Greg Kroah-Hartman
Date: Sun Jun 09 2019 - 13:10:54 EST


From: Patrik Jakobsson <patrik.r.jakobsson@xxxxxxxxx>

commit 7c420636860a719049fae9403e2c87804f53bdde upstream.

Some machines have an lvds child device in vbt even though a panel is
not attached. To make detection more reliable we now also check the lvds
config bits available in the vbt.

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1665766
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@xxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20190416114607.1072-1-patrik.r.jakobsson@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/gpu/drm/gma500/cdv_intel_lvds.c | 3 +++
drivers/gpu/drm/gma500/intel_bios.c | 3 +++
drivers/gpu/drm/gma500/psb_drv.h | 1 +
3 files changed, 7 insertions(+)

--- a/drivers/gpu/drm/gma500/cdv_intel_lvds.c
+++ b/drivers/gpu/drm/gma500/cdv_intel_lvds.c
@@ -620,6 +620,9 @@ void cdv_intel_lvds_init(struct drm_devi
int pipe;
u8 pin;

+ if (!dev_priv->lvds_enabled_in_vbt)
+ return;
+
pin = GMBUS_PORT_PANEL;
if (!lvds_is_present_in_vbt(dev, &pin)) {
DRM_DEBUG_KMS("LVDS is not present in VBT\n");
--- a/drivers/gpu/drm/gma500/intel_bios.c
+++ b/drivers/gpu/drm/gma500/intel_bios.c
@@ -436,6 +436,9 @@ parse_driver_features(struct drm_psb_pri
if (driver->lvds_config == BDB_DRIVER_FEATURE_EDP)
dev_priv->edp.support = 1;

+ dev_priv->lvds_enabled_in_vbt = driver->lvds_config != 0;
+ DRM_DEBUG_KMS("LVDS VBT config bits: 0x%x\n", driver->lvds_config);
+
/* This bit means to use 96Mhz for DPLL_A or not */
if (driver->primary_lfp_id)
dev_priv->dplla_96mhz = true;
--- a/drivers/gpu/drm/gma500/psb_drv.h
+++ b/drivers/gpu/drm/gma500/psb_drv.h
@@ -536,6 +536,7 @@ struct drm_psb_private {
int lvds_ssc_freq;
bool is_lvds_on;
bool is_mipi_on;
+ bool lvds_enabled_in_vbt;
u32 mipi_ctrl_display;

unsigned int core_freq;