[PATCH V3 0/8] IOMMU probe deferral support

Resending, missed out on the link last time.

-----Original Message-----

From: linux-arm-msm-owner@vger.kernel.org [mailto:linux-arm-msm-owner at vger.kernel.org] On Behalf Of Marek Szyprowski

Sent: Monday, October 10, 2016 6:07 PM
To: Sricharan R <redacted>; will.deacon at arm.com; robin.murphy at arm.com; joro at 8bytes.org; iommu at lists.linux-
foundation.org; linux-arm-kernel at lists.infradead.org; linux-arm-msm at vger.kernel.org; laurent.pinchart at ideasonboard.com;
tfiga at chromium.org; srinivas.kandagatla at linaro.org
Subject: Re: [PATCH V3 0/8] IOMMU probe deferral support

Hi Sricharan,


On 2016-10-04 19:03, Sricharan R wrote:

quoted

Initial post from Laurent Pinchart[1]. This is
series calls the dma ops configuration for the devices
at a generic place so that it works for all busses.
The dma_configure_ops for a device is now called during
the device_attach callback just before the probe of the
bus/driver is called. Similarly dma_deconfigure is called during
device/driver_detach path.


pci_bus_add_devices    (platform/amba)(_device_create/driver_register)
        |                         |
pci_bus_add_device     (device_add/driver_register)
        |                         |
device_attach           device_initial_probe
        |                         |
__device_attach_driver    __device_attach_driver
        |
driver_probe_device
        |
really_probe
        |
dma_configure

  Similarly on the device/driver_unregister path __device_release_driver
is
  called which inturn calls dma_deconfigure.

  If the ACPI bus code follows the same, we can add acpi_dma_configure
  at the same place as of_dma_configure.

  This series is based on the recently merged Generic DT bindings for
  PCI IOMMUs and ARM SMMU from Robin Murphy robin.murphy at arm.com [2]

  This time tested this with platform and pci device for probe deferral
  and reprobe on arm64 based platform. There is an issue on the cleanup
  path for arm64 though, where there is WARN_ON if the dma_ops is reset
while
  device is attached to an domain in arch_teardown_dma_ops.
  But with iommu_groups created from the iommu driver, the device is
always
  attached to a domain/default_domain. So so the WARN has to be
removed/handled
  probably.

Thanks for continuing work on this feature! Your can add my:

Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>

Hi Will,Robin,Joerg,
       
       I have tested the probe deferral for platform/pcie bus devices based on latest Generic DT bindings
        series merged [1], for pci/arm-smmu.
       It will be good to know from you on whats the right way to take this forward ?

[1] http://www.spinics.net/lists/devicetree/msg142943.html

Regards,
 Sricharan