On Fri, Apr 20, 2018 at 11:59:13AM +0200, Geert Uytterhoeven wrote: > Hi Christoph, > > On Fri, Apr 20, 2018 at 10:31 AM, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > > On Wed, Apr 18, 2018 at 03:13:14PM +0200, jacopo mondi wrote: > >> As long as it goes for arch/sh, the only user of dma_alloc_coherent() > >> is platform_resource_setup_memory(), and it has been fixed by this > >> patch. > > > > Great! > > > >> Unfortunately, as Thomas pointed out, there are drivers which calls > >> into this with the wrong 'struct device' as the sh_eth one he had fixed. > > > > Yes, we'll need fixes there. Other DMA ops implementations also look > > at struct device, so they generally are buggy. > > > >> I would then say that as long as it goes for the NULL case, we should be > >> fine now. > > > > Then I'd say skil that part, please. > > The major reason for keeping the NULL WARN_ON() checks is to make it > obvious to the developer what is wrong, and fall back to the old behavior. > > Without the checks, the kernel will just crash during early startup, > without a clue in the (missing) kernel output, usually leading to a > frustrating bisection experience (if the developer is sufficiently motivated, > at all). > > Hence my vote for keeping the checks. Sounds good to me. Rich
