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>

1 files changed, 33 insertions, 0 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_combios.c b/drivers/gpu/drm/radeon/radeon_combios.c
index e208d730f51..257ce1774e4 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)
 {