Re: [PATCH v5 0/3] soc: qcom: extend interface for big endian support

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

On 1/21/26 10:07 AM, Alexander Wilhelm wrote:
> On Wed, Jan 21, 2026 at 09:22:07AM +0100, David Heidelberg wrote:
>> On 19/11/2025 11:40, Alexander Wilhelm wrote:
>>> Currently, the QMI interface only works on little endian systems due to how
>>> it encodes and decodes data. Most QMI related data structures are defined
>>> in CPU native order and do not use endian specific types.
>>>
>>> Add support for endian conversion of basic element types in the QMI
>>> encoding and decoding logic. Fix the handling of QMI_DATA_LEN fields to
>>> ensure correct interpretation on big endian systems. These changes are
>>> required to allow QMI to operate correctly across architectures with
>>> different endianness.
>>> ---
>>
>> Hello,
>>
>> I recently (next-20260119) started receiving errors on Pixel 3:
>>
>> [   21.158943] ipa 1e40000.ipa: received modem running event
>> [   21.164616] qmi_encode: Invalid data length
>> [   21.168930] qcom_q6v5_pas remoteproc-adsp: failed to send subsystem event
>> [   21.175844] qmi_encode: Invalid data length
>> [   21.180494] qcom_q6v5_pas remoteproc-cdsp: failed to send subsystem event
>> [   21.187467] qmi_encode: Invalid data length
>> [   21.191772] qcom-q6v5-mss 4080000.remoteproc: failed to send subsystem
>> event
>> [   21.199088] qmi_encode: Invalid data length
>> [   21.203360] qcom-q6v5-mss 4080000.remoteproc: failed to send subsystem
>> event
>> [   21.210636] remoteproc remoteproc0: remote processor 4080000.remoteproc
>> is now up
>>
>> Since it's not well tested, I believe there could be problem with
>> configuration, but after reverting this series, no errors pop up.
>>
>> I would believe maybe these errors was previously hidden, but just to be
>> sure asking here.
> 
> Hi David,
> 
> This is exactly the problem I was afraid of. When the endianness fixes for
> `ath12k` were rejected, I implemented them in the QMI subsystem instead. I only
> tested this with `ath11k` and `ath12k` drivers, both on little-endian and
> big-endian platforms. However, other devices, such as your modem, also rely on
> QMI, but were not tested.
> 
> The difference now is that, instead of using memcpy, basic elements like `u8`,
> `u16`, `u32`, and `u64` are handled explicitly in separate switch-cases. This
> raises the question of what exactly the modem and its corresponding driver are
> doing at this point. Could you please tell me which repository you are working
> on? I could not find `next-20260119` in either the `ath` or the `stable`
> repositories.

next-foo comes from linux-next.git

git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git

Konrad