Re: [PATCH V4 0/8] PCI: ACPI: Setting up DMA coherency for PCI device from _CCA attribute

["Rafael J. Wysocki" <rjw@rjwysocki.net>]

On Tuesday, October 27, 2015 09:52:50 AM Bjorn Helgaas wrote:
> Hi Suravee,
> 
> On Wed, Oct 21, 2015 at 08:52:03AM -0700, Suravee Suthikulpanit wrote:
> > This patch series adds support to setup DMA coherency for PCI device using
> > the ACPI _CCA attribute. According to the ACPI spec, the _CCA attribute
> > is required for ARM64. Therefore, this patch is a pre-req for ACPI PCI
> > support for ARM64 which is currently in development.  Also, this should
> > not affect other architectures that does not define 
> > CONFIG_ACPI_CCA_REQUIRED, since the default value is coherent.
> > 
> > In the process, this series also introduces enum dev_dma_attr and a set
> > of APIs to query device DMA attribute. These APIs replace the obsolete
> > device_dma_is_coherent(), and acpi_check_dma().
> > 
> > I have also included a patch from Jeremy posted here:
> >     http://www.spinics.net/lists/linux-usb/msg128582.html
> > 
> > This patch series  has been tested on AMD Seattle RevB platform.
> > The git tree containing tested code and pre-req patches are posted here:
> > 
> >     http://github.com/ssuthiku/linux.git pci-cca-v4
> > 
> > Changes from V3: (https://lkml.org/lkml/2015/8/26/389)
> >     * Clean up suggested by Bjorn
> >     * Introduce enum dev_dma_attr
> >     * Replace device_dma_is_coherent() and acpi_check_dma() with
> >       new APIs.
> > 
> > Changes from V2: (https://lkml.org/lkml/2015/8/25/549)
> >     * Return -ENOSUPP instead of -1 (per Rafael's suggestion)
> >     * Add WARN() when fail to setup DMA for PCI device when booting
> >       ACPI (per Arnd's suggestion)
> >     * Added Acked-by from Rob.
> >     * Minor clean up
> > 
> > Changes from V1: (https://lkml.org/lkml/2015/8/13/182)
> >     * Include patch 1 from Jeremy to enable support for _CCA=0
> >     * Clean up acpi_check_dma() per Bjorn suggestions
> >     * Split the original V1 patch into two patches (patch 3 and 4)
> > 
> > Jeremy Linton (1):
> >   Honor ACPI _CCA attribute setting
> > 
> > Suravee Suthikulpanit (7):
> >   device property: Introducing enum dev_dma_attr
> >   acpi: Adding DMA Attribute APIs for ACPI Device
> >   device property: Adding DMA Attribute APIs for Generic Devices
> >   device property: acpi: Make use of the new DMA Attribute APIs
> >   device property: acpi: Remove unused DMA APIs
> >   PCI: OF: Move of_pci_dma_configure() to pci_dma_configure()
> >   PCI: ACPI: Add support for PCI device DMA coherency
> > 
> >  drivers/acpi/acpi_platform.c              |  7 +++++-
> >  drivers/acpi/glue.c                       |  8 +++---
> >  drivers/acpi/scan.c                       | 42 +++++++++++++++++++++++++++++++
> >  drivers/base/property.c                   | 32 +++++++++++++++++------
> >  drivers/crypto/ccp/ccp-platform.c         |  9 ++++++-
> >  drivers/net/ethernet/amd/xgbe/xgbe-main.c |  9 ++++++-
> >  drivers/of/of_pci.c                       | 20 ---------------
> >  drivers/pci/probe.c                       | 36 ++++++++++++++++++++++++--
> >  include/acpi/acpi_bus.h                   | 36 +++-----------------------
> >  include/linux/acpi.h                      |  7 +++++-
> >  include/linux/of_pci.h                    |  3 ---
> >  include/linux/property.h                  | 10 +++++++-
> >  12 files changed, 145 insertions(+), 74 deletions(-)
> 
> I had a couple minor comments.  It's sort of a toss-up, but this feels
> more ACPI-flavored than PCI, so I assume Rafael will take this whole
> series unless I hear otherwise.

I'll do that.

> Acked-by: Bjorn Helgaas <bhelgaas@google.com>

Thanks for the help with reviewing this!

Rafael