Ezequiel, On Mon, Jul 07, 2014 at 08:37:58PM -0300, Ezequiel Garcia wrote: > On 07 Jul 11:30 AM, Greg Kroah-Hartman wrote: > > On Mon, Jul 07, 2014 at 07:58:18AM -0300, Ezequiel Garcia wrote: > [..] > > > > > > I guess I snipped the thread and lost most of the information about the > > > panic. > > > Here's the original bug report: > > > > > > http://www.spinics.net/lists/arm-kernel/msg344059.html > > > > > > The problem reported involves enabling OMAP IOMMU driver and not any > > > other IOMMU > > > driver. Doing some tracing and adding a few prints, we found that > > > omap_iommu_init() sets a bus notifier for the platform bus type: > > > > > > omap_iommu_init -> bus_set_iommu -> iommu_bus_init: > > > > > > static void iommu_bus_init(struct bus_type *bus, struct iommu_ops *ops) > > > { > > > bus_register_notifier(bus, &iommu_bus_nb); > > > bus_for_each_dev(bus, NULL, ops, add_iommu_group); > > > } > > > > > > But the iommu bus notifier gets called for the 'pci' bus type, which > > > has the iommu_ops field NULL (since it hasn't been set for iommu). > > > > So this is what needs to be figured out, how is the notifier being > > called with a PCI device? Who else called iommu_bus_init() for the PCI > > bus? > > > > Nobody. The only caller of iommu_bus_init() the above OMAP IOMMU. > > However, I found something interesting. Tried to bisect this without much > luck; I did two bisects and ended up in the same merge commit: > > # good: [0f16aa3c24a216d14d7f0587e1cbd2c1b51a38f3] Merge tag 'samsung-dt-3' > of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung into > next/dt > # first bad commit: [755a9ba7bf24a45b6dbf8bb15a5a56c8ed12461a] Merge tag > 'dt-for-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc > into next > > So, after doing a few diff's between that good and bad and searching for > "bus_notifier" changes, saw something strange in > arch/arm/mach-mvebu/coherency.c. > > It seems bus_register_notifier() is been called for platform and pci devices > with the *same* notifier block. Haven't looked close enough, but you mentioned > that could cause trouble? > > This patch fixes the issue here:
Thanks for digging in to this! Please submit this as patch on it's own and I'll merge it in. thx, Jason. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
