[PATCH 2/8] dmaengine: Add flow controller information to dma_slave_config
Viresh Kumar
viresh.kumar at st.com
Wed Jan 18 05:40:51 EST 2012
On 1/18/2012 4:06 PM, Linus Walleij wrote:
> On Tue, Jan 17, 2012 at 10:07 AM, Viresh Kumar <viresh.kumar at st.com> wrote:
>> On 1/17/2012 2:07 PM, Linus Walleij wrote:
> Maybe I should say that it's supposed to transfer information from
> the driver to the DMA engine that:
>
> 1) The driver naturally "knows", like which physical register address
> the FIFO is in or burst width etc and the DMA engine has no
> business knowing.
>
> 2) That needs to change at runtime, like for example how the PL022
> driver request 32, 16 or 8 bit wide transfers depending on bus
> width.
>
> I think master mode could very well be under (1). So the driver knows
> if this hardware expects the DMA engine to drive the transaction or
> if it's the device itself that should drive it.
>
> So I'm starting to think like you :-)
:)
>> One more thing. I missed few things in this patch:
>> - Need to update all instances of struct dma_slave_config with
>> .device_fc = false
>
> All statically defined structs contain zero == false by default
> so it's not needed.
>
> Make sure any dynamic allocations (I don't know of any!)
> are kzalloc() though.
>
I already fixed these in V2.
Most of the drivers created inside routines. They are not getting
initialized to _zero_ , so i had to fix it.
There are few though, who used kzalloc. I didn't touch them.
--
viresh
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