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

Harshal Dev
2026-05-04T11:53:12Z

On 5/4/2026 4:57 PM, Sumit Garg wrote:
> On Mon, May 04, 2026 at 03:33:06PM +0530, Harshal Dev wrote:
>> 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;
>
> inv_arg.ret return a GP TEE error code which doesn't map 1:1 to kernel
> error codes. The client drivers won't benefit without having a way to
> decode those errors. So just printing here can help the user to debug
> any issues.
>
>>
>> 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>
>>
>
> Thanks, I hope with above I can keep your tag.
>

Alright sure, makes sense. Please keep the tag.

Regards,
Harshal

> -Sumit