[PATCH 1/2] soc: fsl: qbman: qman_portal: defer probing when qman is not available
leoyang.li at nxp.com
Tue Sep 25 15:11:44 PDT 2018
On Tue, Sep 25, 2018 at 2:47 PM Olof Johansson <olof at lixom.net> wrote:
> On Thu, Aug 23, 2018 at 11:36 PM Alexandre Belloni
> <alexandre.belloni at bootlin.com> 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 at bootlin.com>
> > ---
> > 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;
> This is quite late in the probe, after a bunch of resources have been claimed.
> Note that the ioremaps above this are doing unwinds, and you'll end up
> doing duplicate ioremaps if you come in and probe again.
> You should probably unwind those allocations, or move them to devm_*
> or do this check earlier in the function.
Is there any more straightforward indicator on if qman has been
probed? So that we can check it at the begining of the probe?
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