Messages in this thread | | | Subject | Re: [PATCH v6 11/16] dmaengine: tegra-apb: Keep clock enabled only during of DMA transfer | From | Jon Hunter <> | Date | Fri, 31 Jan 2020 09:05:41 +0000 |
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On 30/01/2020 04:37, Dmitry Osipenko wrote: > It's a bit impractical to enable hardware's clock at the time of DMA > channel's allocation because most of DMA client drivers allocate DMA > channel at the time of the driver's probing, and thus, DMA clock is kept > always-enabled in practice, defeating the whole purpose of runtime PM. > > Signed-off-by: Dmitry Osipenko <digetx@gmail.com> > --- > drivers/dma/tegra20-apb-dma.c | 47 ++++++++++++++++++++++++----------- > 1 file changed, 32 insertions(+), 15 deletions(-) > > diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c > index 22b88ccff05d..0ee28d8e3c96 100644 > --- a/drivers/dma/tegra20-apb-dma.c > +++ b/drivers/dma/tegra20-apb-dma.c > @@ -436,6 +436,8 @@ static void tegra_dma_stop(struct tegra_dma_channel *tdc) > tdc_write(tdc, TEGRA_APBDMA_CHAN_STATUS, status); > } > tdc->busy = false; > + > + pm_runtime_put(tdc->tdma->dev);
There are only 3 places where tegra_dma_stop is called, does it simplify the code if we move the pm_runtime_put() outside of tegra_dma_stop? In other words, everywhere there is a tegra_dma_stop, afterwards we then call pm_runtime_put?
This would allow us to get rid of the extra pm_runtime_get in terminate_all.
Jon
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