<snip>
> > + break;
> > + default:
> > + achan->slave.src_maxburst = 0;
> > + achan->slave.dst_maxburst = 0;
> Why clear these for error cases
With the return I shouldn't need to. I'll fix this.
> > + ret = -EINVAL;
> > + break;
> > + }
> > +
> > + if (!ret)
> > + writel(achan->blk_size,
> > + adev->regs + HI_CRCI_CTL(achan->id, adev->ee));
> and why do we write to HW on this. Shouldn't this be done when you program
> the descriptor?
It could be deferred to later. The main point is that I don't see the
slave_config happening every transaction. I was only modifying it now instead
of making a register write for every transaction.
>
> > +static enum dma_status adm_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
> > + struct dma_tx_state *txstate)
> > +{
> > + struct adm_chan *achan = to_adm_chan(chan);
> > + struct virt_dma_desc *vd;
> > + enum dma_status ret;
> > + unsigned long flags;
> > + size_t residue = 0;
> > +
> > + ret = dma_cookie_status(chan, cookie, txstate);
> > +
> Last arg can be null to this, so before you do residue calcluation and block
> interrupts would make sense to return from here if arg is NULL
Good catch. Will fix.
>
> > + spin_lock_irqsave(&achan->vc.lock, flags);
> > +
> > + vd = vchan_find_desc(&achan->vc, cookie);
> > + if (vd)
> > + residue = container_of(vd, struct adm_async_desc, vd)->length;
> > + else if (achan->curr_txd && achan->curr_txd->vd.tx.cookie == cookie)
> > + residue = achan->curr_txd->length;
> so this is current cookie, so you need to read from HW on current position
There is no way to get current position unfortunately without relying on
unreliable debug registers.
> > +
> > + spin_unlock_irqrestore(&achan->vc.lock, flags);
> > +
> > + dma_set_residue(txstate, residue);
> > +
> > + if (achan->error)
> > + return DMA_ERROR;
> > +
> > + return ret;
>
> --
> ~Vinod
>
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