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 feb0.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] [] (dump_backtrace) from []
(show_stack+0x18/0x1c)
[2.835430] r7:c042da78 r6:0009 r5:6013 r4:
[2.841251] [] (show_stack) from []
(dump_stack+0x84/0xa4)
[2.848632] [] (dump_stack) from [] (__warn+0xd0/0x100)
[2.855739] r5: r4:
[2.859409] [] (__warn) from []
(warn_slowpath_null+0x28/0x30)
[2.867139] r9:0001 r8:ef1dc610 r7:ef114010 r6:ef1dc600 r5:ef114010
r4:ef2f2400
[2.875096] [] (warn_slowpath_null) from []
(drm_connector_unregister_all+0x60/0x68)
[2.884785] [] (drm_connector_unregister_all) from []
(rcar_du_remove+0x1c/0x5c)
[2.894111] r5:ef114010 r4:ef2f2400
[2.897780] [] (rcar_du_remove) from []
(rcar_du_probe+0x1d0/0x210)
[2.905953] r5:ef2f2400 r4:fdfb
[2.909625] [] (rcar_du_probe) from []
(platform_drv_probe+0x58/0xa8)
[2.917976] r9: 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
---
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;
}
--
2.8.0.rc3
