[PATCH] drm/tilcdc: Check priv->crtc validity in cpufreq_transition()

[Jyri Sarha]

On 02/08/2019 11:39, Peter Ujfalusi wrote:
> The notifier can be called before we have crtc. With the check we can avoid
> NULL pointer dereference within tilcdc_crtc_update_clk().
> 
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi at ti.com>

Peter, do you have "drm/tilcdc: Register cpufreq notifier after we have
initialized crtc" [1] in your branch? It was merged in v5.0. If you do
and still see the crash, then I need to study this more.

Best regards,
Jyri

[1] https://patchwork.freedesktop.org/patch/292412/
    commit 432973fd3a20102840d5f7e61af9f1a03c217a4c

> ---
>  drivers/gpu/drm/tilcdc/tilcdc_drv.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.c b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
> index 3046a4a4232d..85093123722d 100644
> --- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c
> +++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
> @@ -169,7 +169,7 @@ static int cpufreq_transition(struct notifier_block *nb,
>  	struct tilcdc_drm_private *priv = container_of(nb,
>  			struct tilcdc_drm_private, freq_transition);
>  
> -	if (val == CPUFREQ_POSTCHANGE)
> +	if (val == CPUFREQ_POSTCHANGE && priv->crtc)
>  		tilcdc_crtc_update_clk(priv->crtc);
>  
>  	return 0;
> 


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