> On 17/09/2021 15:11, Akhil R wrote:
> > +static int tegra_dma_slave_config(struct dma_chan *dc,
> > + struct dma_slave_config *sconfig) {
> > + struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
> > +
> > + if (tdc->dma_desc) {
> > + dev_err(tdc2dev(tdc), "Configuration not allowed\n");
> > + return -EBUSY;
> > + }
> > +
> > + memcpy(&tdc->dma_sconfig, sconfig, sizeof(*sconfig));
> > + if (tdc->slave_id == -1)
> > + tdc->slave_id = sconfig->slave_id;
> > +
> > + tdc->config_init = true;
> > + return 0;
> > +}
>
> So you have a function to reserve a slave ID, but you don't check here if it is
> already reserved.
slave-id is reserved considering the direction as well.
'direction' is available only during prep_slave_sg function, I guess.
>
> ...
>
> > +
> > + iommu_spec = dev_iommu_fwspec_get(&pdev->dev);
> > + if (!iommu_spec) {
> > + dev_err(&pdev->dev, "Missing iommu stream-id\n");
> > + return -EINVAL;
> > + }
> > + stream_id = iommu_spec->ids[0] & 0xffff;
>
> Is it an error if the ID is greater than 0xffff?
The value should correspond to one of the GPC DMA Clients listed in
include/dt-bindings/memory/tegra186-mc.h.
I saw similar masking in other tegra drivers also for stream-id.
Would add fixes for other comments in the next version.
Thanks,
Akhil
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nvpublic
