drm: rcar-du: Simplify and fix probe error handling

It isn't safe to call drm_dev_unregister() without first initializing
mode setting with drm_mode_config_init(). This leads to a crash if
either IO memory can't be remapped or vblank initialization fails.

Fix this by reordering the initialization sequence. Move vblank
initialization after the drm_mode_config_init() call, and move IO
remapping before drm_dev_alloc() to avoid the need to perform clean up
in case of failure.

While at it remove the explicit drm_vblank_cleanup() call from
rcar_du_remove() as the drm_dev_unregister() function already cleans up
vblank.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_drv.c b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
index b619a8024ec9c68dac9fd59d7e514a672c3eda0c..4f0acea1e013c0032422ff126c8202d23d962e1b 100644 (file)
--- a/drivers/gpu/drm/rcar-du/rcar_du_drv.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
@@ -285,7 +285,6 @@ static int rcar_du_remove(struct platform_device *pdev)
 
        drm_kms_helper_poll_fini(ddev);
        drm_mode_config_cleanup(ddev);
-       drm_vblank_cleanup(ddev);
 
        drm_dev_unref(ddev);
 
@@ -299,7 +298,7 @@ static int rcar_du_probe(struct platform_device *pdev)
        struct resource *mem;
        int ret;
 
-       /* Allocate and initialize the DRM and R-Car device structures. */
+       /* Allocate and initialize the R-Car device structure. */
        rcdu = devm_kzalloc(&pdev->dev, sizeof(*rcdu), GFP_KERNEL);
        if (rcdu == NULL)
                return -ENOMEM;
@@ -309,31 +308,22 @@ static int rcar_du_probe(struct platform_device *pdev)
        rcdu->dev = &pdev->dev;
        rcdu->info = of_match_device(rcar_du_of_table, rcdu->dev)->data;
 
-       ddev = drm_dev_alloc(&rcar_du_driver, &pdev->dev);
-       if (IS_ERR(ddev))
-               return PTR_ERR(ddev);
-
-       rcdu->ddev = ddev;
-       ddev->dev_private = rcdu;
-
        platform_set_drvdata(pdev, rcdu);
 
        /* I/O resources */
        mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        rcdu->mmio = devm_ioremap_resource(&pdev->dev, mem);
-       if (IS_ERR(rcdu->mmio)) {
-               ret = PTR_ERR(rcdu->mmio);
-               goto error;
-       }
-
-       /* Initialize vertical blanking interrupts handling. Start with vblank
-        * disabled for all CRTCs.
-        */
-       ret = drm_vblank_init(ddev, (1 << rcdu->info->num_crtcs) - 1);
-       if (ret < 0)
-               goto error;
+       if (IS_ERR(rcdu->mmio))
+               return PTR_ERR(rcdu->mmio);
 
        /* DRM/KMS objects */
+       ddev = drm_dev_alloc(&rcar_du_driver, &pdev->dev);
+       if (IS_ERR(ddev))
+               return PTR_ERR(ddev);
+
+       rcdu->ddev = ddev;
+       ddev->dev_private = rcdu;
+
        ret = rcar_du_modeset_init(rcdu);
        if (ret < 0) {
                if (ret != -EPROBE_DEFER)

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_kms.c b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
index d3ab10602e3e26858ac154f052be6c51d6f81a8a..184ed7a155f62f3cf3dc58911c4b31719580d01f 100644 (file)
--- a/drivers/gpu/drm/rcar-du/rcar_du_kms.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
@@ -559,6 +559,13 @@ int rcar_du_modeset_init(struct rcar_du_device *rcdu)
        if (ret < 0)
                return ret;
 
+       /* Initialize vertical blanking interrupts handling. Start with vblank
+        * disabled for all CRTCs.
+        */
+       ret = drm_vblank_init(dev, (1 << rcdu->info->num_crtcs) - 1);
+       if (ret < 0)
+               return ret;
+
        /* Initialize the groups. */
        num_groups = DIV_ROUND_UP(rcdu->num_crtcs, 2);