Re: [PATCH] drm/exynos: init vblank with real number of crtcs

From: Inki Dae
Date: Tue Oct 07 2014 - 11:28:37 EST



Sorry for late.

On 2014ë 10ì 07ì 21:27, Andrzej Hajda wrote:
> Hi Inki,
>
> Gently ping.
>
> Andrzej
>
>
> On 09/19/2014 02:57 PM, Andrzej Hajda wrote:
>> Initialization of vblank with MAX_CRTC caused attempts
>> to disabling vblanks for non-existing crtcs in case
>> drm used fewer crtcs. The patch fixes it.

Nice catch~ This patch also resolves unbind issue. When exynos driver is
unbound, disable_vblank callback is called as dev->num_crtcs so if the
number of probed crtc drivers is different from the one of enabled crtc
drivers then it could attempt to disabling vblank for non-existing crtc,
which in turn, null pointer access occurs.

Thanks,
Inki Dae

>>
>> Signed-off-by: Andrzej Hajda <a.hajda@xxxxxxxxxxx>
>> ---
>> drivers/gpu/drm/exynos/exynos_drm_drv.c | 18 +++++++++---------
>> 1 file changed, 9 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.c b/drivers/gpu/drm/exynos/exynos_drm_drv.c
>> index 9b00e4e..dc4affd 100644
>> --- a/drivers/gpu/drm/exynos/exynos_drm_drv.c
>> +++ b/drivers/gpu/drm/exynos/exynos_drm_drv.c
>> @@ -94,10 +94,6 @@ static int exynos_drm_load(struct drm_device *dev, unsigned long flags)
>> /* init kms poll for handling hpd */
>> drm_kms_helper_poll_init(dev);
>>
>> - ret = drm_vblank_init(dev, MAX_CRTC);
>> - if (ret)
>> - goto err_mode_config_cleanup;
>> -
>> /* setup possible_clones. */
>> exynos_drm_encoder_setup(dev);
>>
>> @@ -106,22 +102,26 @@ static int exynos_drm_load(struct drm_device *dev, unsigned long flags)
>> /* Try to bind all sub drivers. */
>> ret = component_bind_all(dev->dev, dev);
>> if (ret)
>> - goto err_cleanup_vblank;
>> + goto err_mode_config_cleanup;
>> +
>> + ret = drm_vblank_init(dev, dev->mode_config.num_crtc);
>> + if (ret)
>> + goto err_unbind_all;
>>
>> /* Probe non kms sub drivers and virtual display driver. */
>> ret = exynos_drm_device_subdrv_probe(dev);
>> if (ret)
>> - goto err_unbind_all;
>> + goto err_cleanup_vblank;
>>
>> /* force connectors detection */
>> drm_helper_hpd_irq_event(dev);
>>
>> return 0;
>>
>> -err_unbind_all:
>> - component_unbind_all(dev->dev, dev);
>> err_cleanup_vblank:
>> drm_vblank_cleanup(dev);
>> +err_unbind_all:
>> + component_unbind_all(dev->dev, dev);
>> err_mode_config_cleanup:
>> drm_mode_config_cleanup(dev);
>> drm_release_iommu_mapping(dev);
>> @@ -138,8 +138,8 @@ static int exynos_drm_unload(struct drm_device *dev)
>> exynos_drm_fbdev_fini(dev);
>> drm_kms_helper_poll_fini(dev);
>>
>> - component_unbind_all(dev->dev, dev);
>> drm_vblank_cleanup(dev);
>> + component_unbind_all(dev->dev, dev);
>> drm_mode_config_cleanup(dev);
>> drm_release_iommu_mapping(dev);
>>
>>
>
>

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