From: joelf@ti•com (Joel Fernandes)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v2 08/14] DMA: edma: Use different eventq for cyclic channels
Date: Thu, 10 Apr 2014 11:36:30 -0500 [thread overview]
Message-ID: <5346C88E.8010504@ti.com> (raw)
In-Reply-To: <1396357575-30585-9-git-send-email-peter.ujfalusi@ti.com>
On 04/01/2014 08:06 AM, Peter Ujfalusi wrote:
> To improve latency with cyclic DMA operation it is preferred to
> use different eventq/tc than the default which is used by all
> other drivers (mmc, spi, i2c, etc).
> When preparing the cyclic dma ask for non default queue for the
> channel which is going to be used with cyclic mode.
>
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti•com>
> ---
> drivers/dma/edma.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c
> index 1dd9e8806975..10048b40fac8 100644
> --- a/drivers/dma/edma.c
> +++ b/drivers/dma/edma.c
> @@ -628,6 +628,9 @@ static struct dma_async_tx_descriptor *edma_prep_dma_cyclic(
> edesc->pset[i].opt |= TCINTEN;
> }
>
> + /* Use different eventq/tc for cyclic DMA to reduce latency */
> + edma_request_non_default_queue(echan->ch_num);
> +
> return vchan_tx_prep(&echan->vchan, &edesc->vdesc, tx_flags);
> }
>
>
Is there any way to guarantee that the non-default queue is of the
highest priority, or in other words default queue is of lowest priority.
I know you set queue 1 as default because by default 0 is higher
priority. And then assigning non-default queue.
When assigning default to Queue 1, it would be good to also call
assign_priority_to_queue and set QUEPRI to 7 for Queue 1. Since 0, 2 and
4 are all non-defaults.
Thanks,
-Joel
next prev parent reply other threads:[~2014-04-10 16:36 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
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 [this message]
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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