drm/radeon/kms: add support for hardcoded edids in rom (v2)

Some servers hardcode an edid in rom so that they will
work properly with KVMs.  This is a port of the relevant
code from the ddx.

[airlied: reworked to validate edid at boot stage - and
remove special quirk, if there is a valid EDID in the BIOS rom
we'll just try and use it.]

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

4 files changed, 66 insertions, 17 deletions

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index f665b05592f3..f41e91ceaea6 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -60,8 +60,7 @@
 #define EDID_QUIRK_FIRST_DETAILED_PREFERRED     (1 << 5)
 /* use +hsync +vsync for detailed mode */
 #define EDID_QUIRK_DETAILED_SYNC_PP             (1 << 6)
-/* define the number of Extension EDID block */
-#define MAX_EDID_EXT_NUM 4
+
 
 #define LEVEL_DMT       0
 #define LEVEL_GTF       1
@@ -114,14 +113,14 @@ static const u8 edid_header[] = {
 };
 
 /**
- * edid_is_valid - sanity check EDID data
+ * drm_edid_is_valid - sanity check EDID data
  * @edid: EDID data
  *
  * Sanity check the EDID block by looking at the header, the version number
  * and the checksum.  Return 0 if the EDID doesn't check out, or 1 if it's
  * valid.
  */
-static bool edid_is_valid(struct edid *edid)
+bool drm_edid_is_valid(struct edid *edid)
 {
         int i, score = 0;
         u8 csum = 0;
@@ -163,6 +162,7 @@ bad:
         }
         return 0;
 }
+EXPORT_SYMBOL(drm_edid_is_valid);
 
 /**
  * edid_vendor - match a string against EDID's obfuscated vendor field
@@ -1069,8 +1069,8 @@ static int add_detailed_info_eedid(struct drm_connector *connector,
         }
 
         /* Chose real EDID extension number */
-        edid_ext_num = edid->extensions > MAX_EDID_EXT_NUM ?
-                       MAX_EDID_EXT_NUM : edid->extensions;
+        edid_ext_num = edid->extensions > DRM_MAX_EDID_EXT_NUM ?
+                DRM_MAX_EDID_EXT_NUM : edid->extensions;
 
         /* Find CEA extension */
         for (i = 0; i < edid_ext_num; i++) {
@@ -1152,7 +1152,7 @@ static int drm_ddc_read_edid(struct drm_connector *connector,
         for (i = 0; i < 4; i++) {
                 if (drm_do_probe_ddc_edid(adapter, buf, len))
                         return -1;
-                if (edid_is_valid((struct edid *)buf))
+                if (drm_edid_is_valid((struct edid *)buf))
                         return 0;
         }
 
@@ -1177,7 +1177,7 @@ struct edid *drm_get_edid(struct drm_connector *connector,
         int ret;
         struct edid *edid;
 
-        edid = kmalloc(EDID_LENGTH * (MAX_EDID_EXT_NUM + 1),
+        edid = kmalloc(EDID_LENGTH * (DRM_MAX_EDID_EXT_NUM + 1),
                        GFP_KERNEL);
         if (edid == NULL) {
                 dev_warn(&connector->dev->pdev->dev,
@@ -1195,14 +1195,14 @@ struct edid *drm_get_edid(struct drm_connector *connector,
         if (edid->extensions != 0) {
                 int edid_ext_num = edid->extensions;
 
-                if (edid_ext_num > MAX_EDID_EXT_NUM) {
+                if (edid_ext_num > DRM_MAX_EDID_EXT_NUM) {
                         dev_warn(&connector->dev->pdev->dev,
                                  "The number of extension(%d) is "
                                  "over max (%d), actually read number (%d)\n",
-                                 edid_ext_num, MAX_EDID_EXT_NUM,
-                                 MAX_EDID_EXT_NUM);
+                                 edid_ext_num, DRM_MAX_EDID_EXT_NUM,
+                                 DRM_MAX_EDID_EXT_NUM);
                         /* Reset EDID extension number to be read */
-                        edid_ext_num = MAX_EDID_EXT_NUM;
+                        edid_ext_num = DRM_MAX_EDID_EXT_NUM;
                 }
                 /* Read EDID including extensions too */
                 ret = drm_ddc_read_edid(connector, adapter, (char *)edid,
@@ -1245,8 +1245,8 @@ bool drm_detect_hdmi_monitor(struct edid *edid)
                 goto end;
 
         /* Chose real EDID extension number */
-        edid_ext_num = edid->extensions > MAX_EDID_EXT_NUM ?
-                       MAX_EDID_EXT_NUM : edid->extensions;
+        edid_ext_num = edid->extensions > DRM_MAX_EDID_EXT_NUM ?
+                       DRM_MAX_EDID_EXT_NUM : edid->extensions;
 
         /* Find CEA extension */
         for (i = 0; i < edid_ext_num; i++) {
@@ -1303,7 +1303,7 @@ int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid)
         if (edid == NULL) {
                 return 0;
         }
-        if (!edid_is_valid(edid)) {
+        if (!drm_edid_is_valid(edid)) {
                 dev_warn(&connector->dev->pdev->dev, "%s: EDID invalid.\n",
                          drm_get_connector_name(connector));
                 return 0;
diff --git a/drivers/gpu/drm/radeon/radeon_combios.c b/drivers/gpu/drm/radeon/radeon_combios.c
index e208d730f514..257ce1774e40 100644
--- a/drivers/gpu/drm/radeon/radeon_combios.c
+++ b/drivers/gpu/drm/radeon/radeon_combios.c
@@ -443,6 +443,39 @@ static uint16_t combios_get_table_offset(struct drm_device *dev,
 
 }
 
+bool radeon_combios_check_hardcoded_edid(struct radeon_device *rdev)
+{
+        int edid_info;
+        struct edid *edid;
+        edid_info = combios_get_table_offset(rdev->ddev, COMBIOS_HARDCODED_EDID_TABLE);
+        if (!edid_info)
+                return false;
+
+        edid = kmalloc(EDID_LENGTH * (DRM_MAX_EDID_EXT_NUM + 1),
+                       GFP_KERNEL);
+        if (edid == NULL)
+                return false;
+
+        memcpy((unsigned char *)edid,
+               (unsigned char *)(rdev->bios + edid_info), EDID_LENGTH);
+
+        if (!drm_edid_is_valid(edid)) {
+                kfree(edid);
+                return false;
+        }
+
+        rdev->mode_info.bios_hardcoded_edid = edid;
+        return true;
+}
+
+struct edid *
+radeon_combios_get_hardcoded_edid(struct radeon_device *rdev)
+{
+        if (rdev->mode_info.bios_hardcoded_edid)
+                return rdev->mode_info.bios_hardcoded_edid;
+        return NULL;
+}
+
 static struct radeon_i2c_bus_rec combios_setup_i2c_bus(struct radeon_device *rdev,
                                                        int ddc_line)
 {
diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c
index ec3166bfaa49..79634da7c311 100644
--- a/drivers/gpu/drm/radeon/radeon_display.c
+++ b/drivers/gpu/drm/radeon/radeon_display.c
@@ -352,6 +352,8 @@ static bool radeon_setup_enc_conn(struct drm_device *dev)
 
 int radeon_ddc_get_modes(struct radeon_connector *radeon_connector)
 {
+        struct drm_device *dev = radeon_connector->base.dev;
+        struct radeon_device *rdev = dev->dev_private;
         int ret = 0;
 
         if ((radeon_connector->base.connector_type == DRM_MODE_CONNECTOR_DisplayPort) ||
@@ -366,7 +368,9 @@ int radeon_ddc_get_modes(struct radeon_connector *radeon_connector)
         if (!radeon_connector->edid) {
                 radeon_connector->edid = drm_get_edid(&radeon_connector->base, &radeon_connector->ddc_bus->adapter);
         }
-
+        /* some servers provide a hardcoded edid in rom for KVMs */
+        if (!radeon_connector->edid)
+                radeon_connector->edid = radeon_combios_get_hardcoded_edid(rdev);
         if (radeon_connector->edid) {
                 drm_mode_connector_update_edid_property(&radeon_connector->base, radeon_connector->edid);
                 ret = drm_add_edid_modes(&radeon_connector->base, radeon_connector->edid);
@@ -829,6 +833,12 @@ int radeon_modeset_init(struct radeon_device *rdev)
                 return ret;
         }
 
+        /* check combios for a valid hardcoded EDID - Sun servers */
+        if (!rdev->is_atom_bios) {
+                /* check for hardcoded EDID in BIOS */
+                radeon_combios_check_hardcoded_edid(rdev);
+        }
+
         if (rdev->flags & RADEON_SINGLE_CRTC)
                 num_crtc = 1;
 
@@ -850,6 +860,8 @@ int radeon_modeset_init(struct radeon_device *rdev)
 
 void radeon_modeset_fini(struct radeon_device *rdev)
 {
+        kfree(rdev->mode_info.bios_hardcoded_edid);
+
         if (rdev->mode_info.mode_config_initialized) {
                 radeon_hpd_fini(rdev);
                 drm_mode_config_cleanup(rdev->ddev);
diff --git a/drivers/gpu/drm/radeon/radeon_mode.h b/drivers/gpu/drm/radeon/radeon_mode.h
index b884bacf09ff..71439ba2feeb 100644
--- a/drivers/gpu/drm/radeon/radeon_mode.h
+++ b/drivers/gpu/drm/radeon/radeon_mode.h
@@ -207,7 +207,8 @@ struct radeon_mode_info {
         struct drm_property *tv_std_property;
         /* legacy TMDS PLL detect */
         struct drm_property *tmds_pll_property;
-
+        /* hardcoded DFP edid from BIOS */
+        struct edid *bios_hardcoded_edid;
 };
 
 #define MAX_H_CODE_TIMING_LEN 32
@@ -479,6 +480,9 @@ extern int radeon_crtc_cursor_set(struct drm_crtc *crtc,
 extern int radeon_crtc_cursor_move(struct drm_crtc *crtc,
                                    int x, int y);
 
+extern bool radeon_combios_check_hardcoded_edid(struct radeon_device *rdev);
+extern struct edid *
+radeon_combios_get_hardcoded_edid(struct radeon_device *rdev);
 extern bool radeon_atom_get_clock_info(struct drm_device *dev);
 extern bool radeon_combios_get_clock_info(struct drm_device *dev);
 extern struct radeon_encoder_atom_dig *