From: Vinod Koul <vinod.koul@intel.com>
To: Peter Ujfalusi <peter.ujfalusi@ti.com>
Cc: dan.j.williams@intel.com, tony@atomide.com,
linux@armlinux.org.uk, dmaengine@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org,
arnd@arndb.de
Subject: Re: [PATCH v2 2/2] dmaengine: omap-dma: Support for slave devices with data port window
Date: Tue, 29 Nov 2016 08:47:14 +0530 [thread overview]
Message-ID: <20161129031714.GP6408@localhost> (raw)
In-Reply-To: <985d5898-843b-c3d5-464d-f8b8a1452b43@ti.com>
On Fri, Nov 25, 2016 at 11:38:51AM +0200, Peter Ujfalusi wrote:
>
>
> On 11/25/2016 08:12 AM, Vinod Koul wrote:
> > On Thu, Nov 17, 2016 at 02:50:17PM +0200, Peter Ujfalusi wrote:
> >> @@ -921,11 +931,45 @@ static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg(
> >>
> >> d->ccr = c->ccr | CCR_SYNC_FRAME;
> >> if (dir == DMA_DEV_TO_MEM) {
> >> - d->ccr |= CCR_DST_AMODE_POSTINC | CCR_SRC_AMODE_CONSTANT;
> >> d->csdp = CSDP_DST_BURST_64 | CSDP_DST_PACKED;
> >> +
> >> + d->ccr |= CCR_DST_AMODE_POSTINC;
> >> + if (port_window) {
> >> + d->ccr |= CCR_SRC_AMODE_DBLIDX;
> >> + d->ei = 1;
> >> + /*
> >> + * One frame covers the port_window and by configure
> >> + * the source frame index to be -1 * (port_window - 1)
> >> + * we instruct the sDMA that after a frame is processed
> >> + * it should move back to the start of the window.
> >> + */
> >> + d->fi = -(port_window - 1);
> >> +
> >> + if (port_window >= 64)
> >> + d->csdp = CSDP_SRC_BURST_64 | CSDP_SRC_PACKED;
> >> + else if (port_window >= 32)
> >> + d->csdp = CSDP_SRC_BURST_32 | CSDP_SRC_PACKED;
> >> + else if (port_window >= 16)
> >> + d->csdp = CSDP_SRC_BURST_16 | CSDP_SRC_PACKED;
> >
> > this and other would look better with a switch..
>
> I'm not sure if it will be any better:
>
> switch (port_window) {
> case 0 ... 15:
> break;
> case 16 ... 31:
> d->csdp = CSDP_SRC_BURST_16 | CSDP_SRC_PACKED;
> break;
> case 32 ... 63:
> d->csdp = CSDP_SRC_BURST_32 | CSDP_SRC_PACKED;
> break;
> default:
> d->csdp = CSDP_SRC_BURST_64 | CSDP_SRC_PACKED;
> break;
> }
Yeah agree with you on this..
--
~Vinod
prev parent reply other threads:[~2016-11-29 3:07 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-17 12:50 [PATCH v2 0/2] dmaengine: core/omap-dma: Support for port window Peter Ujfalusi
2016-11-17 12:50 ` [PATCH v2 1/2] dmaengine: dma_slave_config: add support for slave " Peter Ujfalusi
2016-11-29 10:47 ` Peter Ujfalusi
2016-11-29 13:14 ` Vinod Koul
[not found] ` <20161117125017.14954-3-peter.ujfalusi@ti.com>
2016-11-25 6:12 ` [PATCH v2 2/2] dmaengine: omap-dma: Support for slave devices with data " Vinod Koul
2016-11-25 9:38 ` Peter Ujfalusi
2016-11-29 3:17 ` Vinod Koul [this message]
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