Re: [PATCH 21/63] dmaengine: ste_dma40: Don't configure runtimeconfigurable setup during allocate

From: Lee Jones
Date: Wed May 08 2013 - 11:25:10 EST


On Fri, 03 May 2013, Linus Walleij wrote:

> On Fri, May 3, 2013 at 4:32 PM, Lee Jones <lee.jones@xxxxxxxxxx> wrote:
>
> > Using the dmaengine API, allocating and configuring a channel are two
> > separate actions. Here we're removing logical channel configuration from
> > the channel allocating routines.
> >
> > Cc: Vinod Koul <vinod.koul@xxxxxxxxx>
> > Cc: Dan Williams <djbw@xxxxxx>
> > Cc: Per Forlin <per.forlin@xxxxxxxxxxxxxx>
> > Cc: Rabin Vincent <rabin@xxxxxx>
> > Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
> (...)
>
> > @@ -2024,6 +2024,9 @@ static int d40_config_memcpy(struct d40_chan *d40c)
> > d40c->dma_cfg = dma40_memcpy_conf_log;
> > d40c->dma_cfg.dev_type = dma40_memcpy_channels[d40c->chan.chan_id];
> >
> > + d40_log_cfg(&d40c->dma_cfg,
> > + &d40c->log_def.lcsp1, &d40c->log_def.lcsp3);
> > +
>
> So it only gets configured for memcpy now?
>
> What happens if you use a logical channel for a device transfer?
>
> Where will that be configured?

In d40_set_runtime_config()

> /* Fill in register values */
> if (chan_is_logical(d40c))
> d40_log_cfg(cfg, &d40c->log_def.lcsp1, &d40c->log_def.lcsp3);
> else
> d40_phy_cfg(cfg, &d40c->src_def_cfg, &d40c->dst_def_cfg);

> Have you tested this combo?

Yes. All ux500 based DMA use logical channels.

--
Lee Jones
Linaro ST-Ericsson Landing Team Lead
Linaro.org â Open source software for ARM SoCs
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