On Wed, May 21, 2025 at 11:58:49AM +0200, Arnd Bergmann wrote: > > I did not see the entire background of the discussion, but would > point out that this is not supposed to work at all: We're trying to find out why this driver fails under concurrent load. It works perfectly if you do one request at a time, but when you hit it with load coming from both CPUs, it ends up corrupting the data. My suscipicion right now is DMA corruption. One common thread seems to be that if you only use dma_map_sg it works, but if dma_alloc_coherent memory is used then it is corrupted (this isn't proven yet, it's just what the printk patch was showing). Cheers, -- Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
