Re: [PATCH v5 3/4] dmaengine: pl330: Store pointer to slave device

[Marek Szyprowski <m.szyprowski@samsung.com>]

Hi Krzysztof,

On 2017-01-17 18:29, Krzysztof Kozlowski wrote:
> On Tue, Jan 17, 2017 at 01:48:57PM +0100, Marek Szyprowski wrote:
>> Store the pointer to slave device, which requested our channel. It will be
>> later used to implement runtime PM of PL330 DMA controller. Although
>> DMA channels might be requested many times, each DMA peripheral channel is
>> physically dedicated only for specific hardware, so there should be only
>> one slave device for each channel.
>>
>> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
>> Acked-by: Arnd Bergmann <arnd@arndb.de>
> Any particular reason for removing my Reviewed-by? Any changes here?

No changes here. I'm sorry, the tag got lost during rebase.

> Best regards,
> Krzysztof
>
>> ---
>>   drivers/dma/pl330.c | 9 +++++++++
>>   1 file changed, 9 insertions(+)
>>
>> diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
>> index b6b2cc912380..c77a3494659c 100644
>> --- a/drivers/dma/pl330.c
>> +++ b/drivers/dma/pl330.c
>> @@ -450,6 +450,7 @@ struct dma_pl330_chan {
>>   
>>   	/* for runtime pm tracking */
>>   	bool active;
>> +	struct device *slave;
>>   };
>>   
>>   struct pl330_dmac {
>> @@ -2093,6 +2094,14 @@ static struct dma_chan *of_dma_pl330_xlate(struct of_phandle_args *dma_spec,
>>   	if (chan_id >= pl330->num_peripherals)
>>   		return NULL;
>>   
>> +	if (!pl330->peripherals[chan_id].slave) {
>> +		pl330->peripherals[chan_id].slave = slave;
>> +	} else if (pl330->peripherals[chan_id].slave != slave) {
>> +		dev_err(pl330->ddma.dev,
>> +			"Can't use same channel with multiple slave devices!\n");
>> +		return NULL;
>> +	}
>> +
>>   	return dma_get_slave_channel(&pl330->peripherals[chan_id].chan);
>>   }
>>   
>> -- 
>> 1.9.1
>>
>
>

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland