Re: [PATCH v4 1/1] scsi: ufs: core: add device level exception support

[Bao D. Nguyen]

On 4/2/2025 12:49 AM, manivannan.sadhasivam@xxxxxxxxxx wrote:
> Yeah, we should be cautious in changing the uAPI header as it can break the
> userspace applications. Annotating the members that need packed attribute seems
> like the way forward to me.

Yes, I realized potential issue when Bart raised a concern.

> Though, I'd like to understand which architecture has the alignment constraint
> in this structure. Only if an architecture requires 8 byte alignment for __be32
> would be a problem. That too only for osf7 and reserved. But I'm not aware of
> such architectures in use.
When using "__u64 value;" in place of osf3-6, I saw the compiler padded 
4 bytes, so __packed was needed for me to get correct __u64 value. I 
thought even the existing structure utp_upiu_query_v4_0 may need 
__packed on some fields where the driver reads the returned data in 
order to be safe across all architectures. However, without evidence of 
an actual failure, I didn't touch the existing structure. Only raised 
potential issue for discussion.

Thanks, Bao