(Old thread name: Exynos4210: fix power domain for MDMA1 device) This patchset solves the problem of registering AMBA device, which might be a part of power domain. In some cases not all resources needed for device registration might be available, because their provides are not yet probed. The caller for amba_device_add() don't support -EPROBE_DEFER return code, so in such case, success is returned and device is added to special deferred list. Registration of devices from that list is performed everytime when deferred probe action has been performed until it finally succeeds. This patchset originates from the patches for fixing mysterious boot hang on Exynos 4210 SoCs when IOMMU was enabled. There is no direct dependency between IOMMU devices and AMBA devices, however enabling IOMMU changes the device probe order, what results in turning off some power domains during boot. Then the registration of MDMA1 (PL330 AMBA) device happens, what results in system hangs, because the common bus code tries to read PID/CID registers from turned-off device. Best regards Marek Szyprowski Samsung R&D Institute Poland Changelog: v7: - replaced late_initcall approach with a notifier registered to device core v6: https://lkml.org/lkml/2016/4/12/414 - got back to v1-style approach on Russell King request to avoid ABI break - use list for storing deferred devices and retry their registration from late_initcall v5: https://lkml.org/lkml/2016/2/10/179 - added 2 more patches to avoid regression with existing drivers (nvdimm and sa1111), for more information, see https://lkml.org/lkml/2015/12/17/390 - changed thread name to "AMBA: add complete support for power domains" v4: https://lkml.org/lkml/2015/12/2/52 - fixed more issues pointed by Ulf Hansson and Russell King v3: https://lkml.org/lkml/2015/12/1/334 - fixed issues pointed by Ulf Hansson - dropped patch for exynos4210 dts, because it already got queued for merging v2: https://lkml.org/lkml/2015/11/26/229 - added 2 patches from 'On-demand device probing' thread (https://lkml.org/lkml/2015/9/29/189), which move PID/CIR reading from amba_device_add() to amba_match() - moved dev_pm_domain_attach() to amba_match(), which is allowed to return -EPROBE_DEFER v1: http://www.spinics.net/lists/arm-kernel/msg463185.html - initial version Patch summary: Marek Szyprowski (2): drivers: base: add support for registering notifier about deferred probe drivers: amba: properly handle devices with power domains drivers/amba/bus.c | 106 ++++++++++++++++++++++++++++++++++++++++++++----- drivers/base/dd.c | 31 +++++++++++++++ include/linux/device.h | 3 ++ 3 files changed, 130 insertions(+), 10 deletions(-) -- 1.9.2 -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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