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Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management driver

From Mark Rutland <mark.rutland@arm.com>
Newsgroups linux.kernel
Subject Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management driver
Date 2015-10-30 19:30 +0100
Message-ID <qpmB5-LN-35@gated-at.bofh.it> (permalink)
References <qp8eK-oK-5@gated-at.bofh.it> <qpjtw-7np-25@gated-at.bofh.it> <qpmhI-Ey-7@gated-at.bofh.it> <qpmhJ-Ey-25@gated-at.bofh.it> <qpmro-HX-11@gated-at.bofh.it>
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On Fri, Oct 30, 2015 at 08:18:49PM +0200, Andy Shevchenko wrote:
> On Fri, Oct 30, 2015 at 8:08 PM, Sinan Kaya <okaya@codeaurora.org> wrote:
> 
> >> The ACPI tables DSDT and CSRT (more info here:
> >> http://www.acpi.info/links.htm) defines properties.
> >>
> >> DSDT:
> >>   per DMAC: the resources
> >>   per client: FixedDMA descriptor that contains channel / request line
> >> pair.
> >>
> >> CSRT:
> >>   necessary table to map which DMAC provides which request line, thus
> >> request line numbering are global on platform.
> >>
> >> When DMAC driver is probed in the running system it should call as
> >> well registration function from acpi-dma.c.
> >>
> >> All clients when use new DMA slave API gets channel automatically
> >> based on their FixedDMA property.
> >>
> >> So, above is how it should be done. Didn't actually checked what this
> >> driver does.
> >>
> > I was going to reply to all the questions in one pass but let me handle
> > piece by piece.
> >
> > Here are some facts.
> > - This hardware supports memcpy and memset only.
> > - Memset feature was removed from the kernel sometime around 3.14. So no
> > memset support in this driver either.
> > - The hardware does not support DMA slave support
> > - The goal is to provide an interface to DMA engine framework for memcpy
> > optimization so that the rest of the kernel drivers and applications make
> > use of the hardware.
> >
> 
> > CSRT is an Intel specific ACPI table for slave devices.
> 
> Wrong.
> It was designed by Microsoft to support multiple controllers, in
> particular DMACs.
> Have you read that document I posted link to?
> 
> > It was decided by
> > Linaro that CSRT will not be supported for ARM64.
> 
> Interesting, ARM64 platforms are not going to have more than one DMAC
> per system?

I cannot imagine that being true, and I don't see why Linaro would
decide such a thing.

It does appear that it's not relevant to this device and driver, given
the lack of clients, unless I've misunderstood?

Thanks,
Mark.
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Thread

[PATCH 1/2] dma: add Qualcomm Technologies HIDMA management driver Sinan Kaya <okaya@codeaurora.org> - 2015-10-30 04:10 +0100
  Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management  driver kbuild test robot <lkp@intel.com> - 2015-10-30 05:40 +0100
  [PATCH] dma: fix platform_no_drv_owner.cocci warnings kbuild test robot <lkp@intel.com> - 2015-10-30 05:40 +0100
  Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management driver Arnd Bergmann <arnd@arndb.de> - 2015-10-30 10:40 +0100
    Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management  driver Sinan Kaya <okaya@codeaurora.org> - 2015-10-31 08:00 +0100
      Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management  driver Timur Tabi <timur@codeaurora.org> - 2015-10-31 14:00 +0100
      Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management  driver Timur Tabi <timur@codeaurora.org> - 2015-10-31 14:00 +0100
      Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management driver Arnd Bergmann <arnd@arndb.de> - 2015-11-02 22:40 +0100
        Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management  driver Sinan Kaya <okaya@codeaurora.org> - 2015-11-03 05:50 +0100
          Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management driver Arnd Bergmann <arnd@arndb.de> - 2015-11-03 13:50 +0100
            Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management  driver Timur Tabi <timur@codeaurora.org> - 2015-11-03 15:30 +0100
            Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management  driver Sinan Kaya <okaya@codeaurora.org> - 2015-11-04 02:10 +0100
  Re: [PATCH 2/2] dma: add Qualcomm Technologies HIDMA channel driver Arnd Bergmann <arnd@arndb.de> - 2015-10-30 11:30 +0100
    Re: [PATCH 2/2] dma: add Qualcomm Technologies HIDMA channel driver Sinan Kaya <okaya@codeaurora.org> - 2015-10-30 22:50 +0100
      Re: [PATCH 2/2] dma: add Qualcomm Technologies HIDMA channel driver Timur Tabi <timur@codeaurora.org> - 2015-10-30 23:00 +0100
        Re: [PATCH 2/2] dma: add Qualcomm Technologies HIDMA channel driver Arnd Bergmann <arnd@arndb.de> - 2015-10-30 23:50 +0100
      Re: [PATCH 2/2] dma: add Qualcomm Technologies HIDMA channel driver Timur Tabi <timur@codeaurora.org> - 2015-10-30 23:40 +0100
        Re: [PATCH 2/2] dma: add Qualcomm Technologies HIDMA channel driver Arnd Bergmann <arnd@arndb.de> - 2015-10-31 00:00 +0100
      Re: [PATCH 2/2] dma: add Qualcomm Technologies HIDMA channel driver Arnd Bergmann <arnd@arndb.de> - 2015-10-30 23:40 +0100
        Re: [PATCH 2/2] dma: add Qualcomm Technologies HIDMA channel driver Sinan Kaya <okaya@codeaurora.org> - 2015-10-31 03:00 +0100
        Re: [PATCH 2/2] dma: add Qualcomm Technologies HIDMA channel driver Sinan Kaya <okaya@codeaurora.org> - 2015-11-01 20:00 +0100
          Re: [PATCH 2/2] dma: add Qualcomm Technologies HIDMA channel driver Timur Tabi <timur@codeaurora.org> - 2015-11-01 21:30 +0100
            Re: [PATCH 2/2] dma: add Qualcomm Technologies HIDMA channel driver Sinan Kaya <okaya@codeaurora.org> - 2015-11-01 21:30 +0100
          Re: [PATCH 2/2] dma: add Qualcomm Technologies HIDMA channel driver Arnd Bergmann <arnd@arndb.de> - 2015-11-02 17:40 +0100
            Re: [PATCH 2/2] dma: add Qualcomm Technologies HIDMA channel driver Sinan Kaya <okaya@codeaurora.org> - 2015-11-02 20:30 +0100
              Re: [PATCH 2/2] dma: add Qualcomm Technologies HIDMA channel driver Arnd Bergmann <arnd@arndb.de> - 2015-11-02 22:00 +0100
                Re: [PATCH 2/2] dma: add Qualcomm Technologies HIDMA channel driver Sinan Kaya <okaya@codeaurora.org> - 2015-11-03 06:30 +0100
                Re: [PATCH 2/2] dma: add Qualcomm Technologies HIDMA channel driver Arnd Bergmann <arnd@arndb.de> - 2015-11-03 11:50 +0100
                Re: [PATCH 2/2] dma: add Qualcomm Technologies HIDMA channel driver Sinan Kaya <okaya@codeaurora.org> - 2015-11-03 22:10 +0100
                Re: [PATCH 2/2] dma: add Qualcomm Technologies HIDMA channel driver Arnd Bergmann <arnd@arndb.de> - 2015-11-03 22:20 +0100
  Re: [PATCH 2/2] dma: add Qualcomm Technologies HIDMA channel driver Mark Rutland <mark.rutland@arm.com> - 2015-10-30 16:00 +0100
    Re: [PATCH 2/2] dma: add Qualcomm Technologies HIDMA channel driver Sinan Kaya <okaya@codeaurora.org> - 2015-10-31 05:30 +0100
  Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management  driver Mark Rutland <mark.rutland@arm.com> - 2015-10-30 16:10 +0100
    Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management driver Andy Shevchenko <andy.shevchenko@gmail.com> - 2015-10-30 19:10 +0100
      Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management  driver Sinan Kaya <okaya@codeaurora.org> - 2015-10-30 19:10 +0100
        Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management  driver Mark Rutland <mark.rutland@arm.com> - 2015-10-30 19:20 +0100
        Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management driver Andy Shevchenko <andy.shevchenko@gmail.com> - 2015-10-30 19:20 +0100
          Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management  driver Mark Rutland <mark.rutland@arm.com> - 2015-10-30 19:30 +0100
            Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management driver Andy Shevchenko <andy.shevchenko@gmail.com> - 2015-10-30 19:50 +0100
              Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management  driver Sinan Kaya <okaya@codeaurora.org> - 2015-10-30 19:50 +0100
                Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management  driver Mark Rutland <mark.rutland@arm.com> - 2015-10-30 20:10 +0100
                Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management  driver Al Stone <al.stone@linaro.org> - 2015-10-30 21:10 +0100
                Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management  driver Mark Rutland <mark.rutland@arm.com> - 2015-10-30 21:20 +0100
                Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management driver Andy Shevchenko <andy.shevchenko@gmail.com> - 2015-10-30 21:20 +0100
                Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management driver Jon Masters <jcm@redhat.com> - 2015-10-31 04:40 +0100
                Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management  driver Sinan Kaya <okaya@codeaurora.org> - 2015-10-31 18:40 +0100
            Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management  driver Sinan Kaya <okaya@codeaurora.org> - 2015-10-30 20:40 +0100
    Re: [PATCH 1/2] dma: add Qualcomm Technologies HIDMA management  driver Sinan Kaya <okaya@codeaurora.org> - 2015-10-31 18:20 +0100

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