On Wed, Sep 08, 2010 at 05:19:25PM +0200, Kay Sievers wrote: > On Wed, Sep 8, 2010 at 16:57, Olof Johansson <olof@xxxxxxxxx> wrote: > > On Wed, Sep 08, 2010 at 10:25:58PM +0800, Lei Wen wrote: > > > >> The patch's purpose is good. As modern sd&mmc is used to host the file > >> system, the 8 partition limitation is becoming a kind of bottleneck... > >> But why not just add GENHD_FL_EXT_DEVT flag to allow mmc use extended > >> partition numbers? > > > > No need to quote the whole patch next time. :) > > > > Given that MMC is sometimes used in deeply embedded environments where > > udev might not be running to take care of dynamic device numbering, > > I chose to stay with a static layout. > > > > I could be convinced otherwise though. It would cause some additional > > hassles for me since we start udev lateish during boot and have a > > prepopulated /dev before that, but that can be dealt with. > > I think the extended number are only used for stuff larger than the static 8? Ah, yes, of course. > Apart from that, you can not reliably or securely use a static /dev > these days, you never know which device you talk to, because the > kernel has far too many dynamically assigned numbers. For that reason, > most embedded setups use the busybox hack to populate /dev. Recent > kernels have a devfs again, and there is no reason today to continue > any static /dev experiments -- unless someone is going over the entire > tree and fixes all the dynamic assignments, which is unlikely to > happen ever. Yeah, it's a weak argument but I wanted to go for the least surprising one for anyone who still relies on static numbering of mmc, since it's used as root device, etc. But with the first 8 minors being the same as before, there's little reason to care about that -- the EXT_DEVT approach will actually be the smaller change, since it won't renumber anything, just extend in a different part of the address space. Lei, want to submit a proper patch for it to replace mine? -Olof -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
