On Tue, Dec 14, 2010 at 21:01, Artem Bityutskiy <dedeki...@gmail.com> wrote: > On Tue, 2010-12-14 at 11:51 -0800, Jason Lunz wrote: >> On Tue, Dec 14, 2010 at 06:24:38PM +0200, Artem Bityutskiy wrote: >> > But I think your solution is a bit dirty, because it adds a great deal >> > of little 'if HAS_IOMEM' and '#ifdef CONFIG_HAS_IOMEM' to many places. >> > This is error-prone. >> >> The intent of that patch was to allow as much of the mtd subsystem to >> compile as possible. My thinking was to try and rectify the fact that >> uml has gone without mtd (and hence jffs2) support for years even though >> much of it works just fine. I think the entire subsystem being marked >> BROKEN in kconfig kept anyone from experimenting with it. >> >> The patch I sent was actually a reaction to feedback I got from Sam >> Ravnborg on my last attempt (um, three years ago :/ ) in which he >> suggested pushing down the ifdefs closer to their points of use. But I >> agree, the minimal version has a much smaller footprint. >> >> The version below still meets the goal of allowing jffs2-on-block2mtd >> usage under uml but is much smaller because only the mtd core is >> included. Compile-tested on i386, x86_64, um/i386, and um/x86_64. >> >> > Instead, you should solve this problem in UML code. I do not know how, >> > but may be you can add readb/writeb there which actually do nothing or >> > print a scary warning, or do BUG(), and let things which use them just >> > fail run-time. >> >> Something like this could work, but it would be error-prone for anyone >> else who attempts using iomem-requiring drivers on uml. Instead of >> getting obvious compile failures we'd have broken drivers that BUG() or >> emit scary warnings. That doesn't seem to me like an improvement. > > This problem does not seem to be mtd-specific, right? So my point was > that it would be nicer to come up with a general solution.
The generic solution for stuff that needs I/O operations is to mark it "depends on HAS_IOMEM". I used a similar patch in the past, IIRC to try axfs on UML. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds ------------------------------------------------------------------------------ Lotusphere 2011 Register now for Lotusphere 2011 and learn how to connect the dots, take your collaborative environment to the next level, and enter the era of Social Business. http://p.sf.net/sfu/lotusphere-d2d _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel