Messages in this thread | | | Date | Sat, 14 Sep 2013 20:33:19 +0200 (CEST) | From | Guennadi Liakhovetski <> | Subject | Re: [PATCH v3] dma: add driver for R-Car HPB-DMAC |
| |
On Sun, 25 Aug 2013, Sergei Shtylyov wrote:
> From: Max Filippov <max.filippov@cogentembedded.com> > > Add support for HPB-DMAC found in Renesas R-Car SoCs, using 'shdma-base' DMA > driver framework. > > Based on the original patch by Phil Edworthy <phil.edworthy@renesas.com>. > > Signed-off-by: Max Filippov <max.filippov@cogentembedded.com> > [Sergei: removed useless #include, sorted #include's, fixed HPB_DMA_TCR_MAX, > fixed formats and removed line breaks in the dev_dbg() calls, rephrased and > added IRQ # to the shdma_request_irq() failure message, added MODULE_AUTHOR(), > removed '__init'/'__exit' annotations from the probe()/remove() methods, removed > '__initdata' annotation from 'hpb_dmae_driver', fixed guard macro name in the > header file, fixed #define ASYNCRSTR_ASRST20, added #define ASYNCRSTR_ASRST24, > added the necessary runtime PM calls to the probe() and remove() methods, > handled errors returned by dma_async_device_register(), beautified comments > and #define's.] > Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> > > ---
[snip]
> Index: slave-dma/drivers/dma/sh/rcar-hpbdma.c > =================================================================== > --- /dev/null > +++ slave-dma/drivers/dma/sh/rcar-hpbdma.c > @@ -0,0 +1,655 @@
[snip]
> +static int hpb_dmae_chan_probe(struct hpb_dmae_device *hpbdev, int id) > +{ > + struct shdma_dev *sdev = &hpbdev->shdma_dev; > + struct platform_device *pdev = > + to_platform_device(hpbdev->shdma_dev.dma_dev.dev); > + struct hpb_dmae_chan *new_hpb_chan; > + struct shdma_chan *schan; > + > + /* Alloc channel */ > + new_hpb_chan = devm_kzalloc(&pdev->dev, > + sizeof(struct hpb_dmae_chan), GFP_KERNEL); > + if (!new_hpb_chan) { > + dev_err(hpbdev->shdma_dev.dma_dev.dev, > + "No free memory for allocating DMA channels!\n"); > + return -ENOMEM; > + } > + > + schan = &new_hpb_chan->shdma_chan;
A suggestion for an incremental patch - you might want to initialise the max_xfer_len field like
schan->max_xfer_len = 64 * 1024 * 1024 - 1;
because if it isn't initialised your max transfer length will be 4k, which will hurt your performance. I think you should get a better throughput after that
> + shdma_chan_probe(sdev, schan, id); > + > + if (pdev->id >= 0) > + snprintf(new_hpb_chan->dev_id, sizeof(new_hpb_chan->dev_id), > + "hpb-dmae%d.%d", pdev->id, id); > + else > + snprintf(new_hpb_chan->dev_id, sizeof(new_hpb_chan->dev_id), > + "hpb-dma.%d", id); > + > + return 0; > +}
Thanks Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/
| |