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From:   Ben Hutchings <ben@decadent.org.uk>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
CC:     akpm@linux-foundation.org, Denis Kirjanov <kda@linux-powerpc.org>,
        "Hans de Goede" <hdegoede@redhat.com>,
        "Patrik Jakobsson" <patrik.r.jakobsson@gmail.com>
Date:   Wed, 02 Oct 2019 20:06:51 +0100
Message-ID: <lsq.1570043211.29533281@decadent.org.uk>
Subject: [PATCH 3.16 10/87] drm/gma500/cdv: Check vbt config bits when
 detecting lvds panels
In-Reply-To: <lsq.1570043210.379046399@decadent.org.uk>
Sender: linux-kernel-owner@vger.kernel.org
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3.16.75-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>

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
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190416114607.1072-1-patrik.r.jakobsson@gmail.com
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
 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
@@ -533,6 +533,7 @@ 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;