Re: [PATCH] dmaengine: ti: edma: Enable support for polled (memcpy) completion

[Peter Ujfalusi <peter.ujfalusi@ti.com>]

On 21/05/2019 8.04, Vinod Koul wrote:
> On 14-05-19, 11:09, Peter Ujfalusi wrote:
>> When a DMA client driver decides that it is not providing callback for
>> completion of a transfer (and/or does not set the DMA_PREP_INTERRUPT) but
>> it will poll the status of the transfer (in case of short memcpy for
>> example) we will not get interrupt for the completion of the transfer and
>> will not mark the transaction as done.
>>
>> Check the event registers (ER and EER) and if the channel is inactive then
>> return wioth DMA_COMPLETE to let the client know that the transfer is
>         ^^^^^
> Typo

Ok

> 
>> completed.
>>
>> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
>> ---
>>  drivers/dma/ti/edma.c | 23 ++++++++++++++++++++---
>>  1 file changed, 20 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/dma/ti/edma.c b/drivers/dma/ti/edma.c
>> index ceabdea40ae0..7501445af069 100644
>> --- a/drivers/dma/ti/edma.c
>> +++ b/drivers/dma/ti/edma.c
>> @@ -1211,8 +1211,9 @@ static struct dma_async_tx_descriptor *edma_prep_dma_memcpy(
>>  
>>  	edesc->pset[0].param.opt |= ITCCHEN;
>>  	if (nslots == 1) {
>> -		/* Enable transfer complete interrupt */
>> -		edesc->pset[0].param.opt |= TCINTEN;
>> +		/* Enable transfer complete interrupt if requested */
>> +		if (tx_flags & DMA_PREP_INTERRUPT)
>> +			edesc->pset[0].param.opt |= TCINTEN;
>>  	} else {
>>  		/* Enable transfer complete chaining for the first slot */
>>  		edesc->pset[0].param.opt |= TCCHEN;
>> @@ -1239,7 +1240,9 @@ static struct dma_async_tx_descriptor *edma_prep_dma_memcpy(
>>  		}
>>  
>>  		edesc->pset[1].param.opt |= ITCCHEN;
>> -		edesc->pset[1].param.opt |= TCINTEN;
>> +		/* Enable transfer complete interrupt if requested */
>> +		if (tx_flags & DMA_PREP_INTERRUPT)
>> +			edesc->pset[1].param.opt |= TCINTEN;
>>  	}
>>  
>>  	return vchan_tx_prep(&echan->vchan, &edesc->vdesc, tx_flags);
>> @@ -1801,6 +1804,20 @@ static enum dma_status edma_tx_status(struct dma_chan *chan,
>>  	unsigned long flags;
>>  
>>  	ret = dma_cookie_status(chan, cookie, txstate);
>> +
>> +	if (ret != DMA_COMPLETE && echan->edesc && !echan->edesc->cyclic) {
>> +		struct edma_cc *ecc = echan->ecc;
>> +		int channel = EDMA_CHAN_SLOT(echan->ch_num);
>> +		int j = (channel >> 5);
>> +		unsigned int mask = BIT(channel & 0x1f);
> 
> GENMASK or define a macro instead of a magic number?

So it is better to change the other places first from where I have just
copied this.

> 
>> +		unsigned int sh_er = edma_shadow0_read_array(ecc, SH_ER, j);
>> +		unsigned int sh_eer = edma_shadow0_read_array(ecc, SH_EER, j);
>> +
>> +		/* The channel is no longer active */
>> +		if (!(sh_er & mask) && !(sh_eer & mask))
>> +			ret = DMA_COMPLETE;
>> +	}
>> +
>>  	if (ret == DMA_COMPLETE || !txstate)
>>  		return ret;
>>  
>> -- 
>> Peter
>>
>> Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
>> Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
> 

- Péter

Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

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