On Wed, Jun 12, 2013 at 8:49 AM, Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote: > On Tue, 11 Jun 2013, Scott Wood wrote: > >> I get the following lockdump output on p2020rdb using >> v3.10-rc5-43-g34376a5. While it's not particularly polite for the >> esdhc driver to be calling OF functions while holding another lock which >> can be acquired from interrupt context, why is devtree_lock usually >> acquired in an irqsafe manner but sometimes not? >> >> Both types of usage were added by the same commit: >> >> commit d6d3c4e656513dcea61ce900f0ecb9ca820ee7cd >> Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx> >> Date: Wed Feb 6 15:30:56 2013 -0500 >> >> OF: convert devtree lock from rw_lock to raw spinlock >> >> Stephen, you asked about this here: >> http://lkml.indiana.edu/hypermail/linux/kernel/1302.1/01383.html >> >> Did you ever get an answer? > > https://patchwork.kernel.org/patch/2470731/ > >> I'm also curious why devtree_lock was made raw to begin with... >> Iterating over a device tree doesn't seem like something you'd want to >> trust to be low-latency. > > The reason is that it's taken in low level cpu bringup code and I did > not find a different solution. :( Hey, Thomas, Do you remember where the offending code is? I'm looking at completely refactoring FDT locking so I'd like to take a crack and solving the cpu bringup problem. g. -- 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
