From: nsekhar@ti•com (Sekhar Nori)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v2 05/14] arm: common: edma: Select event queue 1 as default when booted with DT
Date: Fri, 11 Apr 2014 15:49:46 +0530 [thread overview]
Message-ID: <5347C1C2.6070304@ti.com> (raw)
In-Reply-To: <20140411094217.GA32284@intel.com>
On Friday 11 April 2014 03:12 PM, Vinod Koul wrote:
> On Fri, Apr 11, 2014 at 12:38:00PM +0300, Peter Ujfalusi wrote:
>> On 04/11/2014 11:56 AM, Sekhar Nori wrote:
>>> On Friday 11 April 2014 02:20 PM, Peter Ujfalusi wrote:
>>>> 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@ti•com>
>>>>>
>>>>> Acked-by: Sekhar Nori <nsekhar@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.
>>>
>>> Sounds much better. I had posted some ideas about adding support for
>>> channel priority in the core code but we can leave that for Vinod and
>>> Dan to say if they really see a need for that.
> Is it part of this series?
No, the current series has an EDMA specific way of managing priority.
>
>> If we do it via the dmaengine core I think it would be better to have a new
>> flag to be passed to dmaengine_prep_dma_*().
>> We could have for example:
>> DMA_PREP_HIGH_PRI as flag to indicate that we need high priority DMA if it is
>> possible.
>> We can watch for this flag in the edma driver and act accordingly.
>> ALSA's dmaengine_pcm_prepare_and_submit() could set this flag unconditionally
>> since audio should be treated in this way if the DMA IP can do this.
> Will the priority be different for each descriptor or would be based on channel
> usage. If not then we can add this in dma_slave_config ?
The priority will be per-channel not per-transaction (at least for the
use case we are talking about here).
Thanks,
Sekhar
next prev parent reply other threads:[~2014-04-11 10:19 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-01 13:06 [PATCH v2 00/14] dma: edma: Fixes for cyclic (audio) operation Peter Ujfalusi
2014-04-01 13:06 ` [PATCH v2 01/14] platform_data: edma: Be precise with the paRAM struct Peter Ujfalusi
2014-04-01 13:06 ` [PATCH v2 02/14] dma: edma: Correct the handling of src/dst_maxburst == 0 Peter Ujfalusi
2014-04-01 13:06 ` [PATCH v2 03/14] dma: edma: Add support for DMA_PAUSE/RESUME operation Peter Ujfalusi
2014-04-11 16:43 ` Vinod Koul
2014-04-11 20:51 ` Joel Fernandes
2014-04-01 13:06 ` [PATCH v2 04/14] dma: edma: Set DMA_CYCLIC capability flag Peter Ujfalusi
2014-04-01 13:06 ` [PATCH v2 05/14] arm: common: edma: Select event queue 1 as default when booted with DT Peter Ujfalusi
2014-04-10 16:23 ` Joel Fernandes
2014-04-11 8:17 ` Sekhar Nori
2014-04-11 8:50 ` Peter Ujfalusi
2014-04-11 8:56 ` Sekhar Nori
2014-04-11 9:38 ` Peter Ujfalusi
2014-04-11 9:42 ` Vinod Koul
2014-04-11 10:19 ` Sekhar Nori [this message]
2014-04-11 11:32 ` Peter Ujfalusi
2014-04-11 11:31 ` Vinod Koul
2014-04-11 12:23 ` Peter Ujfalusi
2014-04-11 12:46 ` Vinod Koul
2014-04-14 11:56 ` Peter Ujfalusi
2014-04-14 12:12 ` Sekhar Nori
2014-04-14 12:41 ` Peter Ujfalusi
2014-04-14 14:32 ` Sekhar Nori
2014-04-16 12:59 ` Peter Ujfalusi
2014-04-16 16:05 ` Joel Fernandes
2014-04-24 9:07 ` Peter Ujfalusi
2014-04-11 20:16 ` Joel Fernandes
2014-04-01 13:06 ` [PATCH v2 06/14] arm: common: edma: Save the number of event queues/TCs Peter Ujfalusi
2014-04-01 13:06 ` [PATCH v2 07/14] arm: common: edma: API to request non default queue for a channel Peter Ujfalusi
2014-04-11 8:43 ` Sekhar Nori
2014-04-01 13:06 ` [PATCH v2 08/14] DMA: edma: Use different eventq for cyclic channels Peter Ujfalusi
2014-04-10 16:36 ` Joel Fernandes
2014-04-11 16:47 ` Vinod Koul
2014-04-11 20:56 ` Joel Fernandes
2014-04-01 13:06 ` [PATCH v2 09/14] dma: edma: Implement device_slave_caps callback Peter Ujfalusi
2014-04-01 13:06 ` [PATCH v2 10/14] dma: edma: Simplify direction configuration in edma_config_pset() Peter Ujfalusi
2014-04-10 22:40 ` Joel Fernandes
2014-04-11 6:39 ` Peter Ujfalusi
2014-04-11 19:57 ` Joel Fernandes
2014-04-01 13:06 ` [PATCH v2 11/14] dma: edma: Reduce debug print verbosity for non verbose debugging Peter Ujfalusi
2014-04-01 13:06 ` [PATCH v2 12/14] dma: edma: Prefix debug prints where the text were identical in prep callbacks Peter Ujfalusi
2014-04-01 13:06 ` [PATCH v2 13/14] dma: edma: Add channel number to debug prints Peter Ujfalusi
2014-04-01 13:06 ` [PATCH v2 14/14] dma: edma: Print the direction value as well when it is not supported Peter Ujfalusi
2014-04-10 22:52 ` [PATCH v2 00/14] dma: edma: Fixes for cyclic (audio) operation Joel Fernandes
2014-04-11 16:52 ` Vinod Koul
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