Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1379946

Re: [PATCH 1/2] [v4] net: emac: emac gigabit ethernet controller driver

Show all headers | View raw

On Fri, Apr 15, 2016 at 10:44 AM, Timur Tabi <timur@codeaurora.org> wrote:
> Rob Herring wrote:
>>>
>>> >
>>> >         dma-mask = <0 0xffffffff>;
>>> >
>>> >or
>>> >
>>> >         dma-mask = <0xffffffff 0xffffffff>;
>>
>> No. See dma-ranges.
>
>
> How exactly should I use dma-ranges?  I can't find any other drivers that
> queries that property and uses the result to call dma_set_mask.  I thought
> the dma-ranges property is intended to specify address translation.  I don't
> need to translate any address, I just need to know a single number.

You may only care about the size, but the binding has to handle the
more complex case. Here's an example

<0x0 0x2 0x0 0x1 0x0>

dma address 0 (cell 0) maps to cpu (parent) address 0x2_00000000 (cell
1-2) and the range/size is 4G (cell 3-4).

If you have the same base address, then use the same address. The core
will calculate the mask based on the size. IIRC, we also handle ~0 as
a special case to support 4G for #size-cell=1.

Rob

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Re: [PATCH 1/2] [v4] net: emac: emac gigabit ethernet controller  driver Florian Fainelli <f.fainelli@gmail.com> - 2016-04-14 00:20 +0200
  Re: [PATCH 1/2] [v4] net: emac: emac gigabit ethernet controller  driver Timur Tabi <timur@codeaurora.org> - 2016-04-14 22:30 +0200
    Re: [PATCH 1/2] [v4] net: emac: emac gigabit ethernet controller  driver Florian Fainelli <f.fainelli@gmail.com> - 2016-04-14 23:30 +0200
      Re: [PATCH 1/2] [v4] net: emac: emac gigabit ethernet controller  driver Vikram Sethi <vikrams@codeaurora.org> - 2016-04-15 00:10 +0200
        Re: [PATCH 1/2] [v4] net: emac: emac gigabit ethernet controller  driver Timur Tabi <timur@codeaurora.org> - 2016-04-15 01:40 +0200
          Re: [PATCH 1/2] [v4] net: emac: emac gigabit ethernet controller driver Rob Herring <robh+dt@kernel.org> - 2016-04-15 14:40 +0200
            Re: [PATCH 1/2] [v4] net: emac: emac gigabit ethernet controller  driver Timur Tabi <timur@codeaurora.org> - 2016-04-15 17:50 +0200
              Re: [PATCH 1/2] [v4] net: emac: emac gigabit ethernet controller driver Rob Herring <robh+dt@kernel.org> - 2016-04-15 18:00 +0200
                Re: [PATCH 1/2] [v4] net: emac: emac gigabit ethernet controller  driver Timur Tabi <timur@codeaurora.org> - 2016-04-15 19:30 +0200
          Re: [PATCH 1/2] [v4] net: emac: emac gigabit ethernet controller  driver Bjorn Andersson <bjorn.andersson@linaro.org> - 2016-04-15 18:50 +0200
            Re: [PATCH 1/2] [v4] net: emac: emac gigabit ethernet controller  driver Timur Tabi <timur@codeaurora.org> - 2016-04-15 19:10 +0200
              Re: [PATCH 1/2] [v4] net: emac: emac gigabit ethernet controller  driver Bjorn Andersson <bjorn.andersson@linaro.org> - 2016-04-15 19:40 +0200
                Re: [PATCH 1/2] [v4] net: emac: emac gigabit ethernet controller  driver Timur Tabi <timur@codeaurora.org> - 2016-04-15 20:30 +0200
      Re: [PATCH 1/2] [v4] net: emac: emac gigabit ethernet controller  driver Timur Tabi <timur@codeaurora.org> - 2016-04-21 20:10 +0200
        Re: [PATCH 1/2] [v4] net: emac: emac gigabit ethernet controller  driver Timur Tabi <timur@codeaurora.org> - 2016-04-22 21:50 +0200
          Re: [PATCH 1/2] [v4] net: emac: emac gigabit ethernet controller  driver Florian Fainelli <f.fainelli@gmail.com> - 2016-04-22 22:00 +0200
        Re: [PATCH 1/2] [v4] net: emac: emac gigabit ethernet controller  driver Andrew Lunn <andrew@lunn.ch> - 2016-04-25 15:20 +0200

csiph-web