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 --- drivers/gpu/drm/rcar-du/rcar_du_drv.c | 30 ++++++++++-------------------- drivers/gpu/drm/rcar-du/rcar_du_kms.c | 7 +++++++ 2 files changed, 17 insertions(+), 20 deletions(-)
(Resent with the proper dri-devel mailing list address, sorry for the noise)
I wonder whether it's safe to call drm_dev_unregister() without a previous call to drm_dev_register(), or if it only works at the time being by chance. The function is convenient to implement error handlers without having to resort go lots of goto's or manual tests.
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_drv.c b/drivers/gpu/drm/rcar-du/rcar_du_drv.c index 16ef919f316f..5968c2fa8e33 100644 --- a/drivers/gpu/drm/rcar-du/rcar_du_drv.c +++ b/drivers/gpu/drm/rcar-du/rcar_du_drv.c @@ -334,7 +334,6 @@ 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);
@@ -348,7 +347,7 @@ 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; @@ -358,31 +357,22 @@ 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 1f9f13a80f85..57437e3372a6 100644 --- a/drivers/gpu/drm/rcar-du/rcar_du_kms.c +++ b/drivers/gpu/drm/rcar-du/rcar_du_kms.c @@ -526,6 +526,13 @@ 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);