Subject: [PATCH v3 01/12] dma: edma: Setup parameters to DMA MAX_NR_SG at a time

From: [email-masked] (Joel Fernandes)
Date: Mon, 12 Aug 2013 18:55:48 -0500

Dropped quite a few from the CC list...

On 08/12/2013 02:15 AM, Sekhar Nori wrote:
> On Monday 05 August 2013 09:44 PM, Joel Fernandes wrote:
>> Changes are made here for configuring existing parameters to support
>> DMA'ing them out in batches as needed.
>>
>> Also allocate as many as slots as needed by the SG list, but not more
>> than MAX_NR_SG. Then these slots will be reused accordingly.
>> For ex, if MAX_NR_SG=10, and number of SG entries is 40, still only
>> 10 slots will be allocated to DMA the entire SG list of size 40.
>>
>> Signed-off-by: Joel Fernandes <[email-masked]>
>> ---
>>  drivers/dma/edma.c |   14 +++++++++++---
>>  1 file changed, 11 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c
>> index 5f3e532..7b0853c 100644
>> --- a/drivers/dma/edma.c
>> +++ b/drivers/dma/edma.c
>> @@ -222,9 +222,9 @@ static struct dma_async_tx_descriptor *edma_prep_slave_sg(
>>  	enum dma_slave_buswidth dev_width;
>>  	u32 burst;
>>  	struct scatterlist *sg;
>> -	int i;
>>  	int acnt, bcnt, ccnt, src, dst, cidx;
>>  	int src_bidx, dst_bidx, src_cidx, dst_cidx;
>> +	int i, num_slots_needed;
> 
> 'nslots' is more to my liking. Better keep variable names short.
> 
>>  
>>  	if (unlikely(!echan || !sgl || !sg_len))
>>  		return NULL;
>> @@ -262,8 +262,11 @@ static struct dma_async_tx_descriptor *edma_prep_slave_sg(
>>  
>>  	edesc->pset_nr = sg_len;
>>  
>> -	for_each_sg(sgl, sg, sg_len, i) {
>> -		/* Allocate a PaRAM slot, if needed */
>> +	/* Allocate a PaRAM slot, if needed */
>> +
>> +	num_slots_needed = sg_len > MAX_NR_SG ? MAX_NR_SG : sg_len;
> 
> nslots = min(MAX_NR_SG, sg_len);

I agree the original naming was quite long. I would rather using
something more descriptive though than nslots. How does slots_needed sound?

Thanks,

-Joel