Re: [PATCH v3 0/7] of: setup dma parameters using dma-ranges and dma-coherent

Santosh Shilimkar
2014-05-02T16:42:25Z

On Friday 02 May 2014 10:41 AM, Rob Herring wrote:
> On Thu, May 1, 2014 at 8:25 AM, Russell King - ARM Linux
> <linux@arm.linux.org.uk> wrote:
>> On Thu, May 01, 2014 at 09:19:18AM -0400, Santosh Shilimkar wrote:
>>> Rob, Russell,
>>>
>>> On Thursday 24 April 2014 11:30 AM, Santosh Shilimkar wrote:
>>>> Here is an updated v3 of the series. Series introduces support for setting up
>>>> dma parameters based on device tree properties like 'dma-ranges' and
>>>> 'dma-coherent' and also update to ARM 32 bit port. Earlier version of the
>>>> series can be found here [3], [2] and [1].
>>>>
>>>> The 'dma-ranges' helps to take care of few DMAable system memory restrictions
>>>> by use of dma_pfn_offset which we maintain now per device. Arch code then
>>>> uses it for dma address translations for such cases. We update the
>>>> dma_pfn_offset accordingly during DT the device creation process.The
>>>> 'dma-coherent' property is used to setup arch's coherent dma_ops.
>>>>
>>>> Hopefully with acks, tested-by this version can get into 3.16 queue. I will
>>>> post a followup series for Keystone SOC which will use this infrastructure.
>>>> Linus W also wants to use this for ARM integrator platform dma offset issue.
>>>>
>>>> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>>>> Cc: Russell King <linux@arm.linux.org.uk>
>>>> Cc: Arnd Bergmann <arnd@arndb.de>
>>>> Cc: Olof Johansson <olof@lixom.net>
>>>> Cc: Grant Likely <grant.likely@linaro.org>
>>>> Cc: Rob Herring <robh+dt@kernel.org>
>>>> Cc: Catalin Marinas <catalin.marinas@arm.com>
>>>> Cc: Linus Walleij <linus.walleij@linaro.org>
>>>> Cc: Grygorii Strashko <grygorii.strashko@ti.com>
>>>>
>>>> Grygorii Strashko (2):
>>>> of: introduce of_dma_get_range() helper
>>>> ARM: dma: Use dma_pfn_offset for dma address translation
>>>>
>>>> Santosh Shilimkar (5):
>>>> device: introduce per device dma_pfn_offset
>>>> of: introduce of_dma_is_coherent() helper
>>>> of: configure the platform device dma parameters
>>>> ARM: dma: implement set_arch_dma_coherent_ops()
>>>> ARM: dma: use phys_addr_t in __dma_page_[cpu_to_dev/dev_to_cpu]
>>>>
>>>> arch/arm/include/asm/dma-mapping.h | 28 ++++++++++--
>>>> arch/arm/mm/dma-mapping.c | 4 +-
>>>> drivers/of/address.c | 87 ++++++++++++++++++++++++++++++++++++
>>>> drivers/of/platform.c | 71 +++++++++++++++++++++++++++--
>>>> include/linux/device.h | 2 +
>>>> include/linux/dma-mapping.h | 7 +++
>>>> include/linux/of_address.h | 8 ++++
>>>> include/linux/of_platform.h | 6 +++
>>>> 8 files changed, 204 insertions(+), 9 deletions(-)
>>>>
>>> How do we go about merging this series ? There is a dependency
>>> between the patches and hence the question.
>>
>> I don't know anymore. People today want to assert exclusive rights over
>> parts of the kernel tree, which makes this kind of cross-patching rather
>> impossible.
>
> I can take this series or provide an ack for the DT parts. Either way
> it does not matter to me.
>
>> The only workable solution I can see is the long winded way to split the
>> series up, merge the first set of dependencies in one merge window, and
>> hold the rest back for the following merge window. Not ideal, but it
>> stops the arguments.
>
> That should not be necessary. We should be able to sort this out as it
> is not a difficult problem.
>
yeah. After addressing those few minor comments, I will create a pull
request for both RMK and arm-soc to pull from with your ack. That way
I can also add keystone specific parts on top of this series to arm-soc.

Regards,
Santosh