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

On Fri, Aug 24, 2018 at 9:54 AM Roy Pledge [off-list ref] wrote:

On 8/23/2018 5:36 PM, Alexandre Belloni wrote:

quoted

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@bootlin.com>

Series applied to the fix branch of soc/fsl.

quoted

---
 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@nxp.com>