Re: [PATCH 1/2] soc: fsl: qbman: qman_portal: defer probing when qman is not available

[Roy Pledge]

On 8/23/2018 5:36 PM, Alexandre Belloni wrote:
> If the qman driver (qman_ccsr) doesn't probe or fail to probe before
> qman_portal, qm_ccsr_start will be either NULL or a stale pointer to an
> unmapped page.
>
> This leads to a crash when probing  qman_portal as the init_pcfg function
> calls qman_liodn_fixup that tries to read qman registers.
>
> Assume that qman didn't probe when the pool mask is 0.
>
> Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
> ---
>  drivers/soc/fsl/qbman/qman_portal.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/soc/fsl/qbman/qman_portal.c b/drivers/soc/fsl/qbman/qman_portal.c
> index a120002b630e..4fc80d2c8feb 100644
> --- a/drivers/soc/fsl/qbman/qman_portal.c
> +++ b/drivers/soc/fsl/qbman/qman_portal.c
> @@ -277,6 +277,8 @@ static int qman_portal_probe(struct platform_device *pdev)
>  	}
>  
>  	pcfg->pools = qm_get_pools_sdqcr();
> +	if (pcfg->pools == 0)
> +		return -EPROBE_DEFER;
>  
>  	spin_lock(&qman_lock);
>  	cpu = cpumask_next_zero(-1, &portal_cpus);

Reviewed-by: Roy Pledge <roy.pledge@xxxxxxx>