On Tue, 31 Mar 2009 09:51:53 +0200 (CEST), Geert Uytterhoeven <Geert.Uytterhoeven@xxxxxxxxxxx> wrote: > > Followup to "[PATCH 03/10] ide: destroy DMA mappings after ending DMA" > > email on March 14th: > > http://lkml.org/lkml/2009/3/14/17 > > > > No maintainer is listed for "Toshiba CELL Reference Set IDE" (BLK_DEV_CELLEB) > > or tx4939ide.c in MAINTAINERS. I've CC'd "Ishizaki Kou" @Toshiba (Maintainer for > > "Spidernet Network Driver for CELL") and linuxppc-dev list in the hope > > someone else > > would know or would be able to ACK this patch. > > tx49xx is MIPS, for Nemoto-san. > > > This patch: > > o replaces "mask" variable in ide_dma_end() with #define. > > o removes use of wmb() in ide-dma-sff.c and scc_pata.c. > > o is not tested - I don't have (or want) the HW. > > > > I did NOT remove wmb() use in tx4939ide.c. tx4939ide.c __raw_writeb() > > for MMIO transactions. __raw_writeb() does NOT guarantee memory > > transaction ordering. The wmb() in tx4939ide.c was just copied from ide_dma_end(). On this MIPS core memory operations are strictly ordered so that the wmb() can be removed. And on MIPS __raw_writeb() and writeb() do same thing except for endian conversion. I will send a patch just for tx4939ide.c. Thank you for suggestion. > > tx4939ide also uses mmiowb(). AFAIK, mmiowb() only has an effect on > > SGI IA64 NUMA machines. I'm not going to guess how this driver might work. On MIPS mmiowb() can be (ab)used to flush write buffer. Please do not drop this mmiowb(). --- Atsushi Nemoto
