Date:   Fri, 17 Feb 2023 11:29:50 -0700
From:   Mathieu Poirier <mathieu.poirier@linaro.org>
To:     "Iuliana Prodan (OSS)" <iuliana.prodan@oss.nxp.com>
Cc:     Bjorn Andersson <andersson@kernel.org>,
        Shawn Guo <shawnguo@kernel.org>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        "S.J. Wang" <shengjiu.wang@nxp.com>,
        Fabio Estevam <festevam@gmail.com>,
        Daniel Baluta <daniel.baluta@nxp.com>,
        Iuliana Prodan <iuliana.prodan@nxp.com>,
        linux-imx <linux-imx@nxp.com>, linux-remoteproc@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Pengutronix Kernel Team <kernel@pengutronix.de>
Subject: Re: [PATCH v5] remoteproc: imx_dsp_rproc: add module parameter to
 ignore ready flag from remote processor
Message-ID: <20230217182950.GA585964@p14s>
References: <20230217094124.9440-1-iuliana.prodan@oss.nxp.com>
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Hi Iuliana,

On Fri, Feb 17, 2023 at 11:41:24AM +0200, Iuliana Prodan (OSS) wrote:
> From: Iuliana Prodan <iuliana.prodan@nxp.com>
> 
> There are cases when we want to test a simple "hello world"
> application on the DSP and we don't have IPC between the cores.
> Therefore, do not wait for a confirmation from the remote processor
> at start.
> 
> Added "no_mailboxes" flag while inserting the module to not initialize
> any mailboxes, and so ignore remote processor reply after start.
> By default, this is off - do not ignore reply from rproc.
> 
> Signed-off-by: Iuliana Prodan <iuliana.prodan@nxp.com>
> Reviewed-by: Daniel Baluta <daniel.baluta@nxp.com>
> ---
> Changes since v4
> - s/ignore_dsp_ready/no_mailboxes
> - make imx_dsp_rproc_mbox_init() a function pointer which,
> based on the no_mailboxes module parameter, can initialize
> the mailboxes (= imx_dsp_rproc_mbox_alloc()), in case they exists,
> otherwise does nothing (= imx_dsp_rproc_mbox_no_alloc()).
> 
> Changes since v3
> - do not instantiate static var to 0, this is done by default
> - do not initialize mailbox if not IPC between the core
> 
> Changes since v2
> - s/ignoreready/ignore_dsp_ready
> 
> Changes since v1
> - change BIT(31) to BIT(1) for REMOTE_SKIP_WAIT
> ---
>  drivers/remoteproc/imx_dsp_rproc.c | 33 ++++++++++++++++++++++++++++--
>  1 file changed, 31 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/remoteproc/imx_dsp_rproc.c b/drivers/remoteproc/imx_dsp_rproc.c
> index 95da1cbefacf..85eea85b1655 100644
> --- a/drivers/remoteproc/imx_dsp_rproc.c
> +++ b/drivers/remoteproc/imx_dsp_rproc.c
> @@ -28,6 +28,15 @@
>  
>  #define DSP_RPROC_CLK_MAX			5
>  
> +/*
> + * Module parameters
> + */
> +static unsigned int no_mailboxes;
> +module_param_named(no_mailboxes, no_mailboxes, int, 0644);
> +MODULE_PARM_DESC(no_mailboxes,
> +		 "There is no mailbox between cores, so ignore remote proc "
> +		 "reply after start, default is 0 (off).");
> +
>  #define REMOTE_IS_READY				BIT(0)
>  #define REMOTE_READY_WAIT_MAX_RETRIES		500
>  
> @@ -172,6 +181,9 @@ static const struct imx_rproc_att imx_dsp_rproc_att_imx8ulp[] = {
>  	{ 0x30000000, 0x90000000, 0x10000000, 0},
>  };
>  
> +/* Initialize the mailboxes between cores, if exists */
> +static int (*imx_dsp_rproc_mbox_init)(struct imx_dsp_rproc *priv);
> +
>  /* Reset function for DSP on i.MX8MP */
>  static int imx8mp_dsp_reset(struct imx_dsp_rproc *priv)
>  {
> @@ -492,12 +504,12 @@ static void imx_dsp_rproc_rxdb_callback(struct mbox_client *cl, void *data)
>  }
>  
>  /**
> - * imx_dsp_rproc_mbox_init() - request mailbox channels
> + * imx_dsp_rproc_mbox_alloc() - request mailbox channels
>   * @priv: private data pointer
>   *
>   * Request three mailbox channels (tx, rx, rxdb).
>   */
> -static int imx_dsp_rproc_mbox_init(struct imx_dsp_rproc *priv)
> +static int imx_dsp_rproc_mbox_alloc(struct imx_dsp_rproc *priv)
>  {
>  	struct device *dev = priv->rproc->dev.parent;
>  	struct mbox_client *cl;
> @@ -560,6 +572,18 @@ static int imx_dsp_rproc_mbox_init(struct imx_dsp_rproc *priv)
>  	return ret;
>  }
>  
> +/**
> + * imx_dsp_rproc_mbox_no_alloc()
> + *
> + * Empty function for no mailbox between cores
> + *
> + * Always return 0
> + */
> +static int imx_dsp_rproc_mbox_no_alloc(struct imx_dsp_rproc *priv)
> +{
> +	return 0;
> +}
> +
>  static void imx_dsp_rproc_free_mbox(struct imx_dsp_rproc *priv)
>  {
>  	mbox_free_channel(priv->tx_ch);
> @@ -903,6 +927,11 @@ static int imx_dsp_rproc_probe(struct platform_device *pdev)
>  	priv->rproc = rproc;
>  	priv->dsp_dcfg = dsp_dcfg;
>  
> +	if (no_mailboxes)
> +		imx_dsp_rproc_mbox_init = imx_dsp_rproc_mbox_no_alloc;
> +	else
> +		imx_dsp_rproc_mbox_init = imx_dsp_rproc_mbox_alloc;
> +

This looks good now.  The merge window for the 6.3 cycle opens on Sunday, which
I find too close to start adding new things.  As such I will apply your patch to
my local branch and publish it in three weeks when v6.3-rc2 comes out.

Thanks,
Mathieu

>  	dev_set_drvdata(dev, rproc);
>  
>  	INIT_WORK(&priv->rproc_work, imx_dsp_rproc_vq_work);
> -- 
> 2.17.1
>