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@xxxxxxxxxxxxxxxx>
---
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);
--
Regards,
Laurent Pinchart
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