[PATCH v2 05/14] arm: common: edma: Select event queue 1 as default when booted with DT
Peter Ujfalusi
peter.ujfalusi at ti.com
Fri Apr 11 01:50:38 PDT 2014
On 04/11/2014 11:17 AM, Sekhar Nori wrote:
> On Tuesday 01 April 2014 06:36 PM, Peter Ujfalusi wrote:
>> Use the EVENTQ_1 for default and leave the EVENTQ_0 to be used by high
>> priority channels, like audio.
>>
>> Signed-off-by: Peter Ujfalusi <peter.ujfalusi at ti.com>
>
> Acked-by: Sekhar Nori <nsekhar at ti.com>
>
>> ---
>> arch/arm/common/edma.c | 3 ++-
>> 1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm/common/edma.c b/arch/arm/common/edma.c
>> index 86a8b263278f..19520e2519d9 100644
>> --- a/arch/arm/common/edma.c
>> +++ b/arch/arm/common/edma.c
>> @@ -1546,7 +1546,8 @@ static int edma_of_parse_dt(struct device *dev,
>>
>> pdata->queue_priority_mapping = queue_priority_map;
>>
>> - pdata->default_queue = 0;
>> + /* select queue 1 as default */
>
> It will be nice to expand the comment with explanation of why this is
> being chosen as default (lower priority queue by default for typical
> bulk data transfer).
Yes, extended comment is a good idea.
For the next version I think I'm going to change the code around default
TC/Queue and the non default queue selection, mostly based on Joel's comment:
EVENTQ_1 as default queue.
Set the EVENTQ_1 priority to 7
EVENTQ_0 priority is going to stay 0 and EVENTQ_2 as 2
Add new member to struct edma, like high_pri_queue.
When we set the queue priorities in edma_probe() we look for the highest
priority queue and save the number in high_pri_queue.
I will rename the edma_request_non_default_queue() to
edma_request_high_pri_queue() and it will assign the channel to the high
priority queue.
I think this way it is going to be more explicit and IMHO a bit more safer in
a sense the we are going to get high priority when we ask for it.
--
Péter
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