Re: [PATCH v8 2/4] dmaengine: tegra: Add tegra gpcdma driver

[Jon Hunter <jonathanh@nvidia.com>]

On 27/09/2021 17:11, Akhil R wrote:
> Adding GPC DMA controller driver for Tegra186 and Tegra194. The driver
> supports dma transfers between memory to memory, IO peripheral to memory
> and memory to IO peripheral.
> 
> Signed-off-by: Pavan Kunapuli <pkunapuli@nvidia.com>
> Signed-off-by: Rajesh Gumasta <rgumasta@nvidia.com>
> Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
> ---
>   drivers/dma/Kconfig            |   12 +
>   drivers/dma/Makefile           |    1 +
>   drivers/dma/tegra186-gpc-dma.c | 1298 ++++++++++++++++++++++++++++++++++++++++
>   3 files changed, 1311 insertions(+)
>   create mode 100644 drivers/dma/tegra186-gpc-dma.c

...

> +static int tegra_dma_terminate_all(struct dma_chan *dc)
> +{
> +	struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
> +	unsigned long wcount = 0;
> +	unsigned long status;
> +	unsigned long flags;
> +	int err;
> +
> +	raw_spin_lock_irqsave(&tdc->lock, flags);
> +
> +	if (!tdc->dma_desc) {
> +		raw_spin_unlock_irqrestore(&tdc->lock, flags);
> +		return 0;
> +	}
> +
> +	if (!tdc->busy)
> +		goto skip_dma_stop;
> +
> +	if (tdc->tdma->chip_data->hw_support_pause)
> +		err = tegra_dma_pause(tdc);
> +	else
> +		err = tegra_dma_stop_client(tdc);
> +
> +	if (err) {
> +		raw_spin_unlock_irqrestore(&tdc->lock, flags);
> +		return err;
> +	}
> +
> +	status = tdc_read(tdc, TEGRA_GPCDMA_CHAN_STATUS);
> +	if (status & TEGRA_GPCDMA_STATUS_ISE_EOC) {
> +		dev_dbg(tdc2dev(tdc), "%s():handling isr\n", __func__);
> +		tegra_dma_xfer_complete(tdc);
> +		status = tdc_read(tdc, TEGRA_GPCDMA_CHAN_STATUS);
> +	}
> +
> +	wcount = tdc_read(tdc, TEGRA_GPCDMA_CHAN_XFER_COUNT);
> +	tegra_dma_stop(tdc);
> +
> +	if (tdc->dma_desc)

This is always true here right?

> +		tdc->dma_desc->bytes_transferred +=
> +			tdc->dma_desc->bytes_requested - (wcount * 4);
> +
> +skip_dma_stop:
> +	tegra_dma_sid_free(tdc);
> +	kfree(tdc->dma_desc);
> +	vchan_free_chan_resources(&tdc->vc);
> +
> +	raw_spin_unlock_irqrestore(&tdc->lock, flags);
> +	return 0;
> +}

...

> +static unsigned int get_burst_size(struct tegra_dma_channel *tdc,
> +				   u32 burst_size, enum dma_slave_buswidth slave_bw,
> +				 int len)

There are a few places like this where the alignment could be fixed.

...

 > +static struct dma_async_tx_descriptor *
 > +tegra_dma_prep_dma_memcpy(struct dma_chan *dc, dma_addr_t dest,
 > +			  dma_addr_t src,	size_t len, unsigned long flags)
 > +{

Spacing here.

> +static struct dma_async_tx_descriptor *
> +tegra_dma_prep_slave_sg(struct dma_chan *dc, struct scatterlist *sgl,
> +			unsigned int sg_len, enum dma_transfer_direction direction,
> +		unsigned long flags, void *context)
> +{

Alignment here.

Jon

-- 
nvpublic