From: Vinod Koul <vinod.koul@intel.com>
To: Hyun Kwon <hyunk@xilinx.com>
Cc: "dmaengine@vger.kernel.org" <dmaengine@vger.kernel.org>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
Michal Simek <michal.simek@xilinx.com>,
Tejas Upadhyay <TEJASU@xilinx.com>
Subject: [2/2] dma: xilinx: dpdma: Add the Xilinx DisplayPort DMA engine driver
Date: Mon, 29 Jan 2018 09:49:35 +0530 [thread overview]
Message-ID: <20180129041927.GJ18649@localhost> (raw)
On Wed, Jan 24, 2018 at 05:45:00PM +0000, Hyun Kwon wrote:
> > > > > +static int xilinx_dpdma_config(struct dma_chan *dchan,
> > > > > + struct dma_slave_config *config)
> > > > > +{
> > > > > + if (config->direction != DMA_MEM_TO_DEV)
> > > > > + return -EINVAL;
> > > >
> > > > ?? Why are the config values not used, how else do you configure the
> > > > channel?
> > > >
> > >
> > > There's not much configuration to be done. Channels are pretty much
> > identical
> > > with fixed configurations.
> >
> > hmmm, you do support DMA_SLAVE right?
> >
>
> Yes, and it's single direction, DMA_MEM_TO_DEV.
Okay how do you find the DMA data width and the burst to apply when you DMA
to device? Are these not programmable?
I think you need to go back and check that part. Moreover a client may send
you parameters and program the Device FIFO, you not honoring those will
result in bad data received on Device, am sure you don't want that
next reply other threads:[~2018-01-29 4:19 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-29 4:19 Vinod Koul [this message]
-- strict thread matches above, loose matches on Subject: below --
2018-01-24 17:45 [2/2] dma: xilinx: dpdma: Add the Xilinx DisplayPort DMA engine driver Hyun Kwon
2018-01-24 14:40 Vinod Koul
2018-01-23 17:03 Hyun Kwon
2018-01-12 14:13 Vinod Koul
2018-01-06 2:14 Hyun Kwon
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