[PATCH] drm: hdlcd: Unwind the DRM setup on error conditions in the right order.

[Robin Murphy]

On 08/06/16 13:56, Liviu Dudau wrote:
> In hdlcd_drm_bind()/hdlcd_drm_unbind() we unwind the DRM setup in the
> wrong order (drm_mode_config_cleanup() before connector and encoder
> had a chance to cleanup their memory or before drm_dev_unregister()).
> The correct order should match in both functions.
>
> Reported-by: Robin Murphy <Robin.Murphy at arm.com>
> Signed-off-by: Liviu Dudau <Liviu.Dudau at arm.com>
> ---
>
> Robin,
>
> I believe this should fix your problems with HDLCD failing to allocate CMA
> memory and then crashing.

Heh, I'm not sure I'd even clocked that there was yet another propblem 
beyond the original gem_free_object() crash. I've just tried 4.7-rc3 
with the relevant fixes for that, and indeed drm_connector_cleanup() 
does go bang, and this patch makes it happy again.

Tested-by: Robin Murphy <robin.murphy at arm.com>

Thanks,
Robin.

>
> Best regards,
> Liviu
>
>   drivers/gpu/drm/arm/hdlcd_drv.c | 8 ++++----
>   1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/arm/hdlcd_drv.c b/drivers/gpu/drm/arm/hdlcd_drv.c
> index 3422ca2..2c6eddb 100644
> --- a/drivers/gpu/drm/arm/hdlcd_drv.c
> +++ b/drivers/gpu/drm/arm/hdlcd_drv.c
> @@ -382,7 +382,6 @@ static int hdlcd_drm_bind(struct device *dev)
>
>   err_fbdev:
>   	drm_kms_helper_poll_fini(drm);
> -	drm_mode_config_cleanup(drm);
>   	drm_vblank_cleanup(drm);
>   err_vblank:
>   	pm_runtime_disable(drm->dev);
> @@ -390,6 +389,7 @@ err_pm_active:
>   	component_unbind_all(dev, drm);
>   err_unregister:
>   	drm_dev_unregister(drm);
> +	drm_mode_config_cleanup(drm);
>   err_unload:
>   	drm_irq_uninstall(drm);
>   	of_reserved_mem_device_release(drm->dev);
> @@ -410,15 +410,15 @@ static void hdlcd_drm_unbind(struct device *dev)
>   		hdlcd->fbdev = NULL;
>   	}
>   	drm_kms_helper_poll_fini(drm);
> -	component_unbind_all(dev, drm);
>   	drm_vblank_cleanup(drm);
> +	component_unbind_all(dev, drm);
>   	pm_runtime_get_sync(drm->dev);
>   	drm_irq_uninstall(drm);
>   	pm_runtime_put_sync(drm->dev);
>   	pm_runtime_disable(drm->dev);
> -	of_reserved_mem_device_release(drm->dev);
> -	drm_mode_config_cleanup(drm);
>   	drm_dev_unregister(drm);
> +	drm_mode_config_cleanup(drm);
> +	of_reserved_mem_device_release(drm->dev);
>   	drm_dev_unref(drm);
>   	drm->dev_private = NULL;
>   	dev_set_drvdata(dev, NULL);
>