Re: [PATCH 2/2] soc: qcom: smp2p: Add support for smp2p v2

[Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>]

On 9/24/25 6:18 AM, Jingyi Wang wrote:
> From: Chris Lew <chris.lew@oss.qualcomm.com>
> 
> Some remoteproc need smp2p v2 support, mirror the version written by the
> remote if the remote supports v2. This is needed if the remote does not
> have backwards compatibility with v1. And reset entry last value on SSR for
> smp2p v2.
> 
> Signed-off-by: Chris Lew <chris.lew@oss.qualcomm.com>
> Co-developed-by: Jingyi Wang <jingyi.wang@oss.qualcomm.com>
> Signed-off-by: Jingyi Wang <jingyi.wang@oss.qualcomm.com>
> ---

[...]

> +static int qcom_smp2p_in_version(struct qcom_smp2p *smp2p)
> +{
> +	unsigned int smem_id = smp2p->smem_items[SMP2P_INBOUND];
> +	unsigned int pid = smp2p->remote_pid;
> +	struct smp2p_smem_item *in;
> +	size_t size;
> +
> +	in = qcom_smem_get(pid, smem_id, &size);
> +	if (IS_ERR(in))
> +		return 0;
> +
> +	return in->version;

are in and out versions supposed to be out of sync in case of
error?

> +}
> +
>  static void qcom_smp2p_start_in(struct qcom_smp2p *smp2p)
>  {
>  	unsigned int smem_id = smp2p->smem_items[SMP2P_INBOUND];
> @@ -516,6 +542,7 @@ static int qcom_smp2p_alloc_outbound_item(struct qcom_smp2p *smp2p)
>  	struct smp2p_smem_item *out;
>  	unsigned smem_id = smp2p->smem_items[SMP2P_OUTBOUND];
>  	unsigned pid = smp2p->remote_pid;
> +	u8 in_version;
>  	int ret;
>  
>  	ret = qcom_smem_alloc(pid, smem_id, sizeof(*out));
> @@ -537,12 +564,14 @@ static int qcom_smp2p_alloc_outbound_item(struct qcom_smp2p *smp2p)
>  	out->valid_entries = 0;
>  	out->features = SMP2P_ALL_FEATURES;
>  
> +	in_version = qcom_smp2p_in_version(smp2p);
> +
>  	/*
>  	 * Make sure the rest of the header is written before we validate the
>  	 * item by writing a valid version number.
>  	 */
>  	wmb();
> -	out->version = 1;
> +	out->version = (in_version) ? in_version : 1;

= in_version ?: 1

Konrad