Re: [PATCH v5 06/11] remoteproc: stm32: Properly set co-processor state when attaching

[Arnaud POULIQUEN <arnaud.pouliquen@st.com>]

Hi Mathieu,

On 7/7/20 11:31 PM, Mathieu Poirier wrote:
> Introduce the required mechanic to set the state of the M4 in order
> to properly deal with scenarios where the co-processor has been
> started by another entity.
> 
> Mainly based on the work published by Arnaud Pouliquen [1].
> 
> [1]. https://patchwork.kernel.org/project/linux-remoteproc/list/?series=239877
> 
> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
>  drivers/remoteproc/stm32_rproc.c | 32 ++++++++++++++++++++++++++++++++
>  1 file changed, 32 insertions(+)
> 
> diff --git a/drivers/remoteproc/stm32_rproc.c b/drivers/remoteproc/stm32_rproc.c
> index 961a53f67ec5..cbeb5ceb15c5 100644
> --- a/drivers/remoteproc/stm32_rproc.c
> +++ b/drivers/remoteproc/stm32_rproc.c
> @@ -39,6 +39,13 @@
>  #define STM32_MBX_VQ1_ID	1
>  #define STM32_MBX_SHUTDOWN	"shutdown"
>  
> +#define M4_STATE_OFF		0
> +#define M4_STATE_INI		1
> +#define M4_STATE_CRUN		2
> +#define M4_STATE_CSTOP		3
> +#define M4_STATE_STANDBY	4
> +#define M4_STATE_CRASH		5
> +
>  struct stm32_syscon {
>  	struct regmap *map;
>  	u32 reg;
> @@ -636,12 +643,30 @@ static int stm32_rproc_parse_dt(struct platform_device *pdev,
>  	return 0;
>  }
>  
> +static int stm32_rproc_get_m4_status(struct stm32_rproc *ddata,
> +				     unsigned int *state)
> +{
> +	/* See stm32_rproc_parse_dt() */
> +	if (!ddata->m4_state.map) {
> +		/*
> +		 * We couldn't get the coprocessor's state, assume
> +		 * it is not running.
> +		 */
> +		state = M4_STATE_OFF;
> +		return 0;
> +	}
> +
> +	return regmap_read(ddata->m4_state.map, ddata->m4_state.reg, state);
> +}
> +
> +
nitpicking:  multiple blank lines here

>  static int stm32_rproc_probe(struct platform_device *pdev)
>  {
>  	struct device *dev = &pdev->dev;
>  	struct stm32_rproc *ddata;
>  	struct device_node *np = dev->of_node;
>  	struct rproc *rproc;
> +	unsigned int state;
>  	int ret;
>  
>  	ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
> @@ -664,6 +689,13 @@ static int stm32_rproc_probe(struct platform_device *pdev)
>  	if (ret)
>  		goto free_rproc;
>  
> +	ret = stm32_rproc_get_m4_status(ddata, &state);
> +	if (ret)
> +		goto free_rproc;
> +
> +	if (state == M4_STATE_CRUN)
> +		rproc->state = RPROC_DETACHED;
> +
>  	rproc->has_iommu = false;
>  	ddata->workqueue = create_workqueue(dev_name(dev));
>  	if (!ddata->workqueue) {
>