drm/ast: astdp: Move locking into EDID helper

The modeset mutex protects EDID retrival from concurrent modeset
operations. Acquire the lock in ast_astdp_read_edid(). Prepares the
code for conversion to struct drm_edid.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240815151953.184679-4-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/ast/ast_dp.c b/drivers/gpu/drm/ast/ast_dp.c
index c7f0f9b5dc3a2c06e0a61c09cf9178d9de678eed..c2b08a414ae4568a2d7192402af5d5d5ec3085f8 100644 (file)
--- a/drivers/gpu/drm/ast/ast_dp.c
+++ b/drivers/gpu/drm/ast/ast_dp.c
@@ -26,6 +26,12 @@ static int ast_astdp_read_edid(struct drm_device *dev, u8 *ediddata)
        int ret = 0;
        u8 i;
 
+       /*
+        * Protect access to I/O registers from concurrent modesetting
+        * by acquiring the I/O-register lock.
+        */
+       mutex_lock(&ast->modeset_lock);
+
        /* Start reading EDID data */
        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xe5, (u8)~AST_IO_VGACRE5_EDID_READ_DONE, 0x00);
 
@@ -95,6 +101,8 @@ out:
        ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xe5, (u8)~AST_IO_VGACRE5_EDID_READ_DONE,
                               AST_IO_VGACRE5_EDID_READ_DONE);
 
+       mutex_unlock(&ast->modeset_lock);
+
        return ret;
 }
 
@@ -324,9 +332,6 @@ static const struct drm_encoder_helper_funcs ast_astdp_encoder_helper_funcs = {
 static int ast_astdp_connector_helper_get_modes(struct drm_connector *connector)
 {
        void *edid;
-       struct drm_device *dev = connector->dev;
-       struct ast_device *ast = to_ast_device(dev);
-
        int succ;
        int count;
 
@@ -334,17 +339,9 @@ static int ast_astdp_connector_helper_get_modes(struct drm_connector *connector)
        if (!edid)
                goto err_drm_connector_update_edid_property;
 
-       /*
-        * Protect access to I/O registers from concurrent modesetting
-        * by acquiring the I/O-register lock.
-        */
-       mutex_lock(&ast->modeset_lock);
-
        succ = ast_astdp_read_edid(connector->dev, edid);
        if (succ < 0)
-               goto err_mutex_unlock;
-
-       mutex_unlock(&ast->modeset_lock);
+               goto err_kfree;
 
        drm_connector_update_edid_property(connector, edid);
        count = drm_add_edid_modes(connector, edid);
@@ -352,8 +349,7 @@ static int ast_astdp_connector_helper_get_modes(struct drm_connector *connector)
 
        return count;
 
-err_mutex_unlock:
-       mutex_unlock(&ast->modeset_lock);
+err_kfree:
        kfree(edid);
 err_drm_connector_update_edid_property:
        drm_connector_update_edid_property(connector, NULL);