On Fri, Aug 03, 2018 at 09:01:19PM -0700, Guenter Roeck wrote: > Testing an USB drive connected to ohci-sm501 results in a large number > of runtime warnings. As far as I can tell this driver uses the HCD_LOCAL_MEM feature flag for memory declared using dma_declare_coherent_memory. Unlike the mormal dma mapping interfaces this special case can actually be freed from interrupt context, and we have a fix for this warning queued up in linux-next: http://git.infradead.org/users/hch/dma-mapping.git/commitdiff/d27fb99f62af7b79c542d161aa5155ed57271ddc That being said I'm generally very unhappy how dma_init_coherent_memory turned out. The idea was to allow device local memory to be hidden behind the DMA API, but in general we use it either as a way to declare special uncache system memory (which would really be the plaform codes job), or as a magic bounce buffer like in the USB code. I plan to eventually untangle this, but it is going to take some time. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
