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Date:   Fri, 4 Oct 2019 21:03:26 -0700
From:   Bjorn Andersson <bjorn.andersson@linaro.org>
To:     Fabien Dessenne <fabien.dessenne@st.com>
Cc:     Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        Alexandre Torgue <alexandre.torgue@st.com>,
        Ohad Ben-Cohen <ohad@wizery.com>,
        linux-stm32@st-md-mailman.stormreply.com,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-remoteproc@vger.kernel.org,
        Loic Pallardy <loic.pallardy@st.com>,
        Arnaud Pouliquen <arnaud.pouliquen@st.com>
Subject: Re: [PATCH] remoteproc: stm32: fix probe error case
Message-ID: <20191005040326.GB5189@tuxbook-pro>
References: <1570190555-12465-1-git-send-email-fabien.dessenne@st.com>
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On Fri 04 Oct 05:02 PDT 2019, Fabien Dessenne wrote:

> If the rproc driver is probed before the mailbox driver and if the rproc
> Device Tree node has some mailbox properties, the rproc driver probe
> shall be deferred instead of being probed without mailbox support.
> 
> Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
> ---
>  drivers/remoteproc/stm32_rproc.c | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/remoteproc/stm32_rproc.c b/drivers/remoteproc/stm32_rproc.c
> index 2cf4b29..410b794 100644
> --- a/drivers/remoteproc/stm32_rproc.c
> +++ b/drivers/remoteproc/stm32_rproc.c
> @@ -310,7 +310,7 @@ static const struct stm32_mbox stm32_rproc_mbox[MBOX_NB_MBX] = {
>  	}
>  };
>  
> -static void stm32_rproc_request_mbox(struct rproc *rproc)
> +static int stm32_rproc_request_mbox(struct rproc *rproc)
>  {
>  	struct stm32_rproc *ddata = rproc->priv;
>  	struct device *dev = &rproc->dev;
> @@ -328,11 +328,15 @@ static void stm32_rproc_request_mbox(struct rproc *rproc)
>  		cl->dev = dev->parent;
>  
>  		ddata->mb[i].chan = mbox_request_channel_byname(cl, name);
> -		if (IS_ERR(ddata->mb[i].chan)) {
> +		if (PTR_ERR(ddata->mb[i].chan) == -EPROBE_DEFER) {

You may not use PTR_ERR() without first checking IS_ERR(), apart from
that your patch looks good.

Regards,
Bjorn

> +			return -EPROBE_DEFER;
> +		} else if (IS_ERR(ddata->mb[i].chan)) {
>  			dev_warn(dev, "cannot get %s mbox\n", name);
>  			ddata->mb[i].chan = NULL;
>  		}
>  	}
> +
> +	return 0;
>  }
>  
>  static int stm32_rproc_set_hold_boot(struct rproc *rproc, bool hold)
> @@ -596,7 +600,9 @@ static int stm32_rproc_probe(struct platform_device *pdev)
>  	if (ret)
>  		goto free_rproc;
>  
> -	stm32_rproc_request_mbox(rproc);
> +	ret = stm32_rproc_request_mbox(rproc);
> +	if (ret)
> +		goto free_rproc;
>  
>  	ret = rproc_add(rproc);
>  	if (ret)
> -- 
> 2.7.4
>