Re: [PATCH v7 06/11] firmware: qcom: scm: add support for object invocation

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

On 8/13/25 11:37 PM, Amirreza Zarrabi wrote:
> 
> 
> On 8/13/2025 7:53 PM, Konrad Dybcio wrote:
>> On 8/13/25 2:35 AM, Amirreza Zarrabi wrote:
>>> Qualcomm TEE (QTEE) hosts Trusted Applications (TAs) and services in
>>> the secure world, accessed via objects. A QTEE client can invoke these
>>> objects to request services. Similarly, QTEE can request services from
>>> the nonsecure world using objects exported to the secure world.
>>>
>>> Add low-level primitives to facilitate the invocation of objects hosted
>>> in QTEE, as well as those hosted in the nonsecure world.
>>>
>>> If support for object invocation is available, the qcom_scm allocates
>>> a dedicated child platform device. The driver for this device communicates
>>> with QTEE using low-level primitives.
>>>
>>> Tested-by: Neil Armstrong <neil.armstrong@linaro.org>
>>> Tested-by: Harshal Dev <quic_hdev@quicinc.com>
>>> Signed-off-by: Amirreza Zarrabi <amirreza.zarrabi@oss.qualcomm.com>
>>> ---

[...]

>>>  /**
>>>   * qcom_scm_is_available() - Checks if SCM is available
>>>   */
>>> @@ -2326,6 +2444,16 @@ static int qcom_scm_probe(struct platform_device *pdev)
>>>  	ret = qcom_scm_qseecom_init(scm);
>>>  	WARN(ret < 0, "failed to initialize qseecom: %d\n", ret);
>>>  
>>> +	/*
>>> +	 * Initialize the QTEE object interface.
>>> +	 *
>>> +	 * This only represents the availability for QTEE object invocation
>>> +	 * and callback support. On failure, ignore the result. Any subsystem
>>> +	 * depending on it may fail if it tries to access this interface.
>>> +	 */
>>> +	ret = qcom_scm_qtee_init(scm);
>>> +	WARN(ret < 0, "failed to initialize qcomtee: %d\n", ret);
>>
>> This will throw a WARN on *a lot* of platforms, ranging from
>> Chromebooks running TF-A (with a reduced SMC handler), through
>> platforms requiring QCOM_SCM_SMCINVOKE_INVOKE_LEGACY (0x00) cmd
>>
> 
> Are you suggesting I remove the WARN? If so, how should the user be notified?
> Should the error simply be ignored?

I suggest using dev_info/dev_notice, WARN prints multiple dozen lines
and taints the kernel

Konrad