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SubjectRe: [PATCH 1/2 v2] dmaengine: rcar-dmac: ensure CHCR DE bit is actually 0 after clear
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Hi Geert

> > DMAC reads data from source device, and buffered it until transferable
> > size for shink device. Because of this behavoir, DMAC is including
>
> sink, behavior
(snip)
> > 0 after cleared.
>
> clearing

Grr, thanks.

> > +static void rcar_dmac_chcr_de_barrier(struct rcar_dmac_chan *chan)
> > +{
> > + u32 chcr;
> > + int i;
>
> unsigned int
>
> > +
> > + /*
> > + * Ensure that the setting of the DE bit is actually 0 after
> > + * clearing it.
> > + */
> > + for (i = 0; i < 1024; i++) {
> > + chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR);
> > + if (!(chcr & RCAR_DMACHCR_DE))
> > + return;
> > + udelay(1);
> > + }
>
> What's a typical number of loops needed before DE is really cleared?

It case by case, but I don't want to use while(1) loop

Best regards
---
Kuninori Morimoto
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