Simply calling rcar_du_remove on any error can cause unbalanced calls to various functions (e.g. drm_connector_register/unregister, drm_dev_register/drm_dev_unref).

This can be seen at bootup of my Porter boards with current next:

[ 2.789322] rcar-du feb00000.display: failed to initialize DRM/KMS (-517) [ 2.796267] ------------[ cut here ]------------ [ 2.800996] WARNING: CPU: 1 PID: 1 at include/drm/drm_crtc.h:2623 drm_connector_unregister_all+0x60/0x68 [ 2.810689] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.6.0-rc2-next-20160405-dirty #11 [ 2.818864] Hardware name: Generic R8A7791 (Flattened Device Tree) [ 2.825174] Backtrace: [ 2.827699] [<c010aa2c>] (dump_backtrace) from [<c010abd8>] (show_stack+0x18/0x1c) [ 2.835430] r7:c042da78 r6:00000009 r5:60000013 r4:00000000 [ 2.841251] [<c010abc0>] (show_stack) from [<c0379244>] (dump_stack+0x84/0xa4) [ 2.848632] [<c03791c0>] (dump_stack) from [<c011c3b0>] (__warn+0xd0/0x100) [ 2.855739] r5:00000000 r4:00000000 [ 2.859409] [<c011c2e0>] (__warn) from [<c011c498>] (warn_slowpath_null+0x28/0x30) [ 2.867139] r9:00000001 r8:ef1dc610 r7:ef114010 r6:ef1dc600 r5:ef114010 r4:ef2f2400 [ 2.875096] [<c011c470>] (warn_slowpath_null) from [<c042da78>] (drm_connector_unregister_all+0x60/0x68) [ 2.884785] [<c042da18>] (drm_connector_unregister_all) from [<c0440ac8>] (rcar_du_remove+0x1c/0x5c) [ 2.894111] r5:ef114010 r4:ef2f2400 [ 2.897780] [<c0440aac>] (rcar_du_remove) from [<c0440d50>] (rcar_du_probe+0x1d0/0x210) [ 2.905953] r5:ef2f2400 r4:fffffdfb [ 2.909625] [<c0440b80>] (rcar_du_probe) from [<c044c1d4>] (platform_drv_probe+0x58/0xa8) [ 2.917976] r9:00000000 r8:c0a1cca4 r7:c0a71a48 r6:c0a1cca4 r5:ef1dc610 r4:c0440b80

Adjust the code to only unwind as necessary on probe failures

Signed-off-by: Sjoerd Simons sjoerd.simons@collabora.co.uk

---

drivers/gpu/drm/rcar-du/rcar_du_drv.c | 32 +++++++++++++++++++++++++------- 1 file changed, 25 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_drv.c b/drivers/gpu/drm/rcar-du/rcar_du_drv.c index 644db36..deb75fa 100644 --- a/drivers/gpu/drm/rcar-du/rcar_du_drv.c +++ b/drivers/gpu/drm/rcar-du/rcar_du_drv.c @@ -333,7 +333,7 @@ static int rcar_du_probe(struct platform_device *pdev) rcdu->mmio = devm_ioremap_resource(&pdev->dev, mem); if (IS_ERR(rcdu->mmio)) { ret = PTR_ERR(rcdu->mmio); - goto error; + goto error_dev; }

/* Initialize vertical blanking interrupts handling. Start with vblank @@ -342,14 +342,17 @@ static int rcar_du_probe(struct platform_device *pdev) ret = drm_vblank_init(ddev, (1 << rcdu->info->num_crtcs) - 1); if (ret < 0) { dev_err(&pdev->dev, "failed to initialize vblank\n"); - goto error; + goto error_dev; }

/* DRM/KMS objects */ ret = rcar_du_modeset_init(rcdu); if (ret < 0) { + /* modeset_init could have failed partway through and doesn't + * do its own cleanup, so needs to be completely undone. + */ dev_err(&pdev->dev, "failed to initialize DRM/KMS (%d)\n", ret); - goto error; + goto error_modeset; }

ddev->irq_enabled = 1; @@ -359,7 +362,7 @@ static int rcar_du_probe(struct platform_device *pdev) */ ret = drm_dev_register(ddev, 0); if (ret) - goto error; + goto error_modeset;

mutex_lock(&ddev->mode_config.mutex); drm_for_each_connector(connector, ddev) { @@ -369,15 +372,30 @@ static int rcar_du_probe(struct platform_device *pdev) } mutex_unlock(&ddev->mode_config.mutex);

+ /* One or more connects could have been registered, so unregister all + * connectors. + */ if (ret < 0) - goto error; + goto error_connector;

DRM_INFO("Device %s probed\n", dev_name(&pdev->dev));

return 0;

-error: - rcar_du_remove(pdev); +error_connector: + drm_connector_unregister_all(ddev); + drm_dev_unregister(ddev); + +error_modeset: + if (rcdu->fbdev) + drm_fbdev_cma_fini(rcdu->fbdev); + + drm_kms_helper_poll_fini(ddev); + drm_mode_config_cleanup(ddev); + drm_vblank_cleanup(ddev); + +error_dev: + drm_dev_unref(ddev);

return ret; }