Hello everybody, I don't think I have ever seen an answer to my question regarding alignment constraints on swiotlb bounce buffers: On Wed, 8 Nov 2023 10:13:47 +0100 Petr Tesařík <petr@xxxxxxxxxxx> wrote: >[...] > To sum it up, there are two types of alignment: > > 1. specified by a device's min_align_mask; this says how many low > bits of a buffer's physical address must be preserved, > > 2. specified by allocation size and/or the alignment parameter; > this says how many low bits in the first IO TLB slot's physical > address must be zero. > > I hope somebody can confirm or correct this summary before I go > and break something. You know, it's not like cleanups in SWIOTLB > have never broken anything. ;-) If no answer means that nobody knows, then based on my understanding the existing code (both implementation and users), I can assume that this is the correct interpretation. I'm giving it a few more days. If there's still no reaction, expect a beautiful documentation patch and a less beautiful cleanup patch in the next week. Petr T
