I2C initialization is allowed to fail. In this case, create a connector without DDC adapter. The current code would dereference a NULL pointer.
Reading the modes from the connector is supposed to work without I2C adapter. Add the respective test.
v2: * init edid to NULL to avoid uninitialized read
Signed-off-by: Thomas Zimmermann tzimmermann@suse.de --- drivers/gpu/drm/ast/ast_mode.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c index 1e30eaeb0e1b..692e7a3b3555 100644 --- a/drivers/gpu/drm/ast/ast_mode.c +++ b/drivers/gpu/drm/ast/ast_mode.c @@ -1210,9 +1210,9 @@ static int ast_get_modes(struct drm_connector *connector) { struct ast_connector *ast_connector = to_ast_connector(connector); struct ast_private *ast = to_ast_private(connector->dev); - struct edid *edid; - int ret; + struct edid *edid = NULL; bool flags = false; + int ret;
if (ast->tx_chip_type == AST_TX_DP501) { ast->dp501_maxclk = 0xff; @@ -1226,7 +1226,7 @@ static int ast_get_modes(struct drm_connector *connector) else kfree(edid); } - if (!flags) + if (!flags && ast_connector->i2c) edid = drm_get_edid(connector, &ast_connector->i2c->adapter); if (edid) { drm_connector_update_edid_property(&ast_connector->base, edid); @@ -1332,10 +1332,13 @@ static int ast_connector_init(struct drm_device *dev) if (!ast_connector->i2c) drm_err(dev, "failed to add ddc bus for connector\n");
- drm_connector_init_with_ddc(dev, connector, - &ast_connector_funcs, - DRM_MODE_CONNECTOR_VGA, - &ast_connector->i2c->adapter); + if (ast_connector->i2c) + drm_connector_init_with_ddc(dev, connector, &ast_connector_funcs, + DRM_MODE_CONNECTOR_VGA, + &ast_connector->i2c->adapter); + else + drm_connector_init(dev, connector, &ast_connector_funcs, + DRM_MODE_CONNECTOR_VGA);
drm_connector_helper_add(connector, &ast_connector_helper_funcs);