On Mon, Aug 24, 2015 at 09:55:03AM +0100, Jon Hunter wrote:
> >> +static int tegra_adma_get_xfer_params(struct tegra_dma_channel *tdc,
> >> + struct tegra_adma_chan_regs *ch_regs,
> >> + enum dma_transfer_direction direction)
> >> +{
> >> + u32 burst_size, ctrl, ctrl_mask, slave_id, fifo_mask, fifo_shift;
> >> +
> >> + ch_regs->ahub_fifo_ctrl = tdc_read(tdc, ADMA_CH_AHUB_FIFO_CTRL);
> >> + ch_regs->config = tdc_read(tdc, ADMA_CH_CONFIG);
> >> + ch_regs->ctrl = tdc_read(tdc, ADMA_CH_CTRL);
> >> + slave_id = tdc->dma_sconfig.slave_id;
> >> +
> >> + switch (direction) {
> >> + case DMA_MEM_TO_DEV:
> >> + burst_size = fls(tdc->dma_sconfig.dst_maxburst);
> >> + ctrl_mask = ADMA_CH_CTRL_TX_REQUEST_SELECT_MASK;
> >> + ctrl = MEMORY_TO_AHUB << ADMA_CH_CTRL_TRANSFER_DIRECTION_SHIFT;
> >> + ctrl |= slave_id << ADMA_CH_CTRL_TX_REQUEST_SELECT_SHIFT;
> >> + fifo_mask = ADMA_CH_AHUB_FIFO_CTRL_TX_FIFO_SIZE_MASK;
> >> + fifo_shift = ADMA_CH_AHUB_FIFO_CTRL_TX_FIFO_SIZE_SHIFT;
> >> + break;
> > Empty line here pls
>
> Ok, any reason why? Other dma drivers don't appear to do this.
This improves readablity. It is a good idea to sprinkle empty lines between
logial blocks
> >> +static int tegra_adma_pm_suspend(struct device *dev)
> >> +{
> >> + struct tegra_dma *tdma = dev_get_drvdata(dev);
> >> + int i;
> >> + int ret;
> >> +
> >> + ret = pm_runtime_get_sync(dev);
> > why is this required :)
>
> To ensure that the clocks are enabled before the registers are read.
> This function saves the dma context before suspend, in case the hardware
> state is lost.
I think same reason here too, so based on my other argument, this may not be
required!
--
~Vinod
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