On Wed, Sep 8, 2010 at 8:57 AM, Olof Johansson <olof@xxxxxxxxx> wrote: > 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? I have a tested patch for this. It also cleans up the connection between devidx and minor numbers. I'll send it shortly. -- 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
