Re: [PATCH v4 04/15] firmware: qcom: Add a PAS TEE service

[Harshal Dev <harshal.dev@oss.qualcomm.com>]

Hi Sumit,

On 4/27/2026 3:25 PM, Sumit Garg via OP-TEE wrote:
> From: Sumit Garg <sumit.garg@oss.qualcomm.com>
> 
> Add support for Peripheral Authentication Service (PAS) driver based
> on TEE bus with OP-TEE providing the backend PAS service implementation.
> 
> The TEE PAS service ABI is designed to be extensible with additional API
> as PTA_QCOM_PAS_CAPABILITIES. This allows to accommodate any future
> extensions of the PAS service needed while still maintaining backwards
> compatibility.
> 
> Signed-off-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
> ---
>  drivers/firmware/qcom/Kconfig        |  10 +
>  drivers/firmware/qcom/Makefile       |   1 +
>  drivers/firmware/qcom/qcom_pas_tee.c | 479 +++++++++++++++++++++++++++
>  3 files changed, 490 insertions(+)
>  create mode 100644 drivers/firmware/qcom/qcom_pas_tee.c

[...]

> diff --git a/drivers/firmware/qcom/qcom_pas_tee.c b/drivers/firmware/qcom/qcom_pas_tee.c

> +static int qcom_pas_tee_mem_setup(struct device *dev, u32 pas_id,
> +				  phys_addr_t addr, phys_addr_t size)
> +{

[...]

> +
> +	ret = tee_client_invoke_func(data->ctx, &inv_arg, param);
> +	if (ret < 0 || inv_arg.ret != 0) {
> +		dev_err(dev, "PAS mem setup failed, pas_id: %d, ret: %d, err: 0x%x\n",
> +			pas_id, ret, inv_arg.ret);
> +		return ret ?: -EINVAL;

Following the example from qcom_scm_pas_mem_setup() here:
https://elixir.bootlin.com/linux/v7.0.1/source/drivers/firmware/qcom/qcom_scm.c#L778

I think it should be:
return ret ?: inv_arg.ret;

This way the client (say mdt_loader) knows what error OPTEE PAS service returned.
I can see that is tries to print this error:
https://elixir.bootlin.com/linux/v7.0.1/source/drivers/soc/qcom/mdt_loader.c#L286

With that,
Reviewed-by: Harshal Dev <harshal.dev@oss.qualcomm.com>

Regards,
Harshal