drm/i915: Preserve the DDI_A_4_LANES bit from the bios

commit bcf53de4e60d9000b82f541d654529e2902a4c2c upstream.

Otherwise the DDI_A_4_LANES bit gets lost and we can't use > 2 lanes
on eDP. This fixes eDP on hsw with > 2 lanes.

Also s/port_reversal/saved_port_bits/ since the current name is
confusing.

Signed-off-by: Stéphane Marchesin <marcheu@chromium.org>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Zhouping Liu <zliu@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index fb961bb..16e674a 100644 (file)
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -684,7 +684,7 @@ static void intel_ddi_mode_set(struct drm_encoder *encoder,
                struct intel_digital_port *intel_dig_port =
                        enc_to_dig_port(encoder);
 
-               intel_dp->DP = intel_dig_port->port_reversal |
+               intel_dp->DP = intel_dig_port->saved_port_bits |
                               DDI_BUF_CTL_ENABLE | DDI_BUF_EMP_400MV_0DB_HSW;
                switch (intel_dp->lane_count) {
                case 1:
@@ -1324,7 +1324,8 @@ static void intel_enable_ddi(struct intel_encoder *intel_encoder)
                 * enabling the port.
                 */
                I915_WRITE(DDI_BUF_CTL(port),
-                          intel_dig_port->port_reversal | DDI_BUF_CTL_ENABLE);
+                          intel_dig_port->saved_port_bits |
+                          DDI_BUF_CTL_ENABLE);
        } else if (type == INTEL_OUTPUT_EDP) {
                struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
 
@@ -1543,8 +1544,9 @@ void intel_ddi_init(struct drm_device *dev, enum port port)
        intel_encoder->get_hw_state = intel_ddi_get_hw_state;
 
        intel_dig_port->port = port;
-       intel_dig_port->port_reversal = I915_READ(DDI_BUF_CTL(port)) &
-                                       DDI_BUF_PORT_REVERSAL;
+       intel_dig_port->saved_port_bits = I915_READ(DDI_BUF_CTL(port)) &
+                                         (DDI_BUF_PORT_REVERSAL |
+                                          DDI_A_4_LANES);
        if (hdmi_connector)
                intel_dig_port->hdmi.hdmi_reg = DDI_BUF_CTL(port);
        intel_dig_port->dp.output_reg = DDI_BUF_CTL(port);

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 624a9e6..7cd5584 100644 (file)
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -426,7 +426,7 @@ struct intel_dp {
 struct intel_digital_port {
        struct intel_encoder base;
        enum port port;
-       u32 port_reversal;
+       u32 saved_port_bits;
        struct intel_dp dp;
        struct intel_hdmi hdmi;
 };