Messages in this thread | ![/](/images/icornerl.gif) | | Subject | Re: [PATCH v3 05/14] dmaengine: Add support for reporting DMA cached data amount | From | Tero Kristo <> | Date | Wed, 9 Oct 2019 12:17:47 +0300 |
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On 01/10/2019 09:16, Peter Ujfalusi wrote: > A DMA hardware can have big cache or FIFO and the amount of data sitting in > the DMA fabric can be an interest for the clients. > > For example in audio we want to know the delay in the data flow and in case > the DMA have significantly large FIFO/cache, it can affect the latenc/delay > > Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Reviewed-by: Tero Kristo <t-kristo@ti.com>
> --- > drivers/dma/dmaengine.h | 8 ++++++++ > include/linux/dmaengine.h | 2 ++ > 2 files changed, 10 insertions(+) > > diff --git a/drivers/dma/dmaengine.h b/drivers/dma/dmaengine.h > index 501c0b063f85..b0b97475707a 100644 > --- a/drivers/dma/dmaengine.h > +++ b/drivers/dma/dmaengine.h > @@ -77,6 +77,7 @@ static inline enum dma_status dma_cookie_status(struct dma_chan *chan, > state->last = complete; > state->used = used; > state->residue = 0; > + state->in_flight_bytes = 0; > } > return dma_async_is_complete(cookie, complete, used); > } > @@ -87,6 +88,13 @@ static inline void dma_set_residue(struct dma_tx_state *state, u32 residue) > state->residue = residue; > } > > +static inline void dma_set_in_flight_bytes(struct dma_tx_state *state, > + u32 in_flight_bytes) > +{ > + if (state) > + state->in_flight_bytes = in_flight_bytes; > +} > + > struct dmaengine_desc_callback { > dma_async_tx_callback callback; > dma_async_tx_callback_result callback_result; > diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h > index 40d062c3b359..02ceef95340a 100644 > --- a/include/linux/dmaengine.h > +++ b/include/linux/dmaengine.h > @@ -682,11 +682,13 @@ static inline struct dma_async_tx_descriptor *txd_next(struct dma_async_tx_descr > * @residue: the remaining number of bytes left to transmit > * on the selected transfer for states DMA_IN_PROGRESS and > * DMA_PAUSED if this is implemented in the driver, else 0 > + * @in_flight_bytes: amount of data in bytes cached by the DMA. > */ > struct dma_tx_state { > dma_cookie_t last; > dma_cookie_t used; > u32 residue; > + u32 in_flight_bytes; > }; > > /** >
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