[PATCH 18/31] ASoC: tegra: allocate AHUB FIFO during probe() not startup()
Thierry Reding
thierry.reding at gmail.com
Wed Dec 4 04:00:13 EST 2013
On Tue, Dec 03, 2013 at 12:55:55PM -0700, Stephen Warren wrote:
> On 11/29/2013 07:40 AM, Thierry Reding wrote:
> > On Fri, Nov 15, 2013 at 01:54:13PM -0700, Stephen Warren wrote:
> >> Teh Tegra30 I2S driver currently allocates DMA FIFOs from the
> >> AHUB only when an audio stream starts playback. This is
> >> theoretically nice for resource sharing, but makes no practical
> >> difference for any configuration the drivers currently support.
> >> However, this deferral prevents conversion to the standard DMA DT
> >> bindings, since conversion requires knowledge of the specific DMA
> >> channel to be allocated, which in turn depends on which specific
> >> FIFO was allocated.
> >>
> >> For this reason, move the FIFO allocate into probe() to allow
> >> later
> ...
> >> + i2s->playback_dma_data.addr_width =
> >> DMA_SLAVE_BUSWIDTH_4_BYTES; + i2s->playback_dma_data.maxburst =
> >> 4; + ret =
> >> tegra30_ahub_allocate_tx_fifo(&i2s->playback_fifo_cif, +
> >> &i2s->playback_dma_data.addr, +
> >> &i2s->playback_dma_data.slave_id); + if (ret) { +
> >> dev_err(&pdev->dev, "Could not alloc TX FIFO: %d\n", ret); +
> >> goto err_suspend; + } + ret =
> >> tegra30_ahub_set_rx_cif_source(i2s->playback_i2s_cif, +
> >> i2s->playback_fifo_cif); + if (ret) { + dev_err(&pdev->dev,
> >> "Could not route TX FIFO: %d\n", ret); + goto err_free_tx_fifo;
> >> + } + + i2s->capture_dma_data.addr_width =
> >> DMA_SLAVE_BUSWIDTH_4_BYTES; + i2s->capture_dma_data.maxburst =
> >> 4; + ret = tegra30_ahub_allocate_rx_fifo(&i2s->capture_fifo_cif,
> >> + &i2s->capture_dma_data.addr, +
> >> &i2s->capture_dma_data.slave_id); + if (ret) { +
> >> dev_err(&pdev->dev, "Could not alloc RX FIFO: %d\n", ret); +
> >> goto err_unroute_tx_fifo; + } + ret =
> >> tegra30_ahub_set_rx_cif_source(i2s->capture_fifo_cif, +
> >> i2s->capture_i2s_cif); + if (ret) { + dev_err(&pdev->dev, "Could
> >> not route TX FIFO: %d\n", ret); + goto err_free_rx_fifo; + } +
> >
> > It could be useful to have these in a separate function so as not
> > to make the .probe() any larger. It's already pretty big as it is.
>
> May I ignore this; I personally prefer larger linear functions; it's
> much easier to follow the code-flow without having to jump back/forth
> between a bunch of single-use functions.
Alright, I won't lose any sleep over it.
Thierry
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