1 files changed, 20 insertions, 1 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_legacy_encoders.c b/drivers/gpu/drm/radeon/radeon_legacy_encoders.c
index 981508ff7037..38e45e231ef5 100644
--- a/drivers/gpu/drm/radeon/radeon_legacy_encoders.c
+++ b/drivers/gpu/drm/radeon/radeon_legacy_encoders.c
@@ -46,6 +46,7 @@ static void radeon_legacy_lvds_dpms(struct drm_encoder *encoder, int mode)
         struct radeon_encoder *radeon_encoder = to_radeon_encoder(encoder);
         uint32_t lvds_gen_cntl, lvds_pll_cntl, pixclks_cntl, disp_pwr_man;
         int panel_pwr_delay = 2000;
+        bool is_mac = false;
         DRM_DEBUG("\n");
 
         if (radeon_encoder->enc_priv) {
@@ -58,6 +59,15 @@ static void radeon_legacy_lvds_dpms(struct drm_encoder *encoder, int mode)
                 }
         }
 
+        /* macs (and possibly some x86 oem systems?) wire up LVDS strangely
+         * Taken from radeonfb.
+         */
+        if ((rdev->mode_info.connector_table == CT_IBOOK) ||
+            (rdev->mode_info.connector_table == CT_POWERBOOK_EXTERNAL) ||
+            (rdev->mode_info.connector_table == CT_POWERBOOK_INTERNAL) ||
+            (rdev->mode_info.connector_table == CT_POWERBOOK_VGA))
+                is_mac = true;
+
         switch (mode) {
         case DRM_MODE_DPMS_ON:
                 disp_pwr_man = RREG32(RADEON_DISP_PWR_MAN);
@@ -74,6 +84,8 @@ static void radeon_legacy_lvds_dpms(struct drm_encoder *encoder, int mode)
 
                 lvds_gen_cntl = RREG32(RADEON_LVDS_GEN_CNTL);
                 lvds_gen_cntl |= (RADEON_LVDS_ON | RADEON_LVDS_EN | RADEON_LVDS_DIGON | RADEON_LVDS_BLON);
+                if (is_mac)
+                        lvds_gen_cntl |= RADEON_LVDS_BL_MOD_EN;
                 lvds_gen_cntl &= ~(RADEON_LVDS_DISPLAY_DIS);
                 udelay(panel_pwr_delay * 1000);
                 WREG32(RADEON_LVDS_GEN_CNTL, lvds_gen_cntl);
@@ -85,7 +97,14 @@ static void radeon_legacy_lvds_dpms(struct drm_encoder *encoder, int mode)
                 WREG32_PLL_P(RADEON_PIXCLKS_CNTL, 0, ~RADEON_PIXCLK_LVDS_ALWAYS_ONb);
                 lvds_gen_cntl = RREG32(RADEON_LVDS_GEN_CNTL);
                 lvds_gen_cntl |= RADEON_LVDS_DISPLAY_DIS;
-                lvds_gen_cntl &= ~(RADEON_LVDS_ON | RADEON_LVDS_BLON | RADEON_LVDS_EN | RADEON_LVDS_DIGON);
+                if (is_mac) {
+                        lvds_gen_cntl &= ~RADEON_LVDS_BL_MOD_EN;
+                        WREG32(RADEON_LVDS_GEN_CNTL, lvds_gen_cntl);
+                        lvds_gen_cntl &= ~(RADEON_LVDS_ON | RADEON_LVDS_EN);
+                } else {
+                        WREG32(RADEON_LVDS_GEN_CNTL, lvds_gen_cntl);
+                        lvds_gen_cntl &= ~(RADEON_LVDS_ON | RADEON_LVDS_BLON | RADEON_LVDS_EN | RADEON_LVDS_DIGON);
+                }
                 udelay(panel_pwr_delay * 1000);
                 WREG32(RADEON_LVDS_GEN_CNTL, lvds_gen_cntl);
                 WREG32_PLL(RADEON_PIXCLKS_CNTL, pixclks_cntl);