Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757560AbcKBVTs (ORCPT ); Wed, 2 Nov 2016 17:19:48 -0400 Received: from galahad.ideasonboard.com ([185.26.127.97]:53520 "EHLO galahad.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757512AbcKBVTp (ORCPT ); Wed, 2 Nov 2016 17:19:45 -0400 From: Laurent Pinchart To: Peter Ujfalusi Cc: mchehab@osg.samsung.com, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH RESEND] media: omap3isp: Use dma_request_chan() to requesting DMA channel Date: Wed, 02 Nov 2016 23:19:36 +0200 Message-ID: <1758201.F0bdTd4b9u@avalon> User-Agent: KMail/4.14.10 (Linux/4.8.6-gentoo; KDE/4.14.24; x86_64; ; ) In-Reply-To: <20161102123959.6098-1-peter.ujfalusi@ti.com> References: <20161102123959.6098-1-peter.ujfalusi@ti.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2645 Lines: 89 Hi Peter, Thank you for the patch. On Wednesday 02 Nov 2016 14:39:59 Peter Ujfalusi wrote: > With the new dma_request_chan() the client driver does not need to look for > the DMA resource and it does not need to pass filter_fn anymore. > By switching to the new API the driver can now support deferred probing > against DMA. I believe this breaks the OMAP3 ISP driver. dma_request_slave_channel_compat() is a superset of dma_request_chan() that will, when called with omap_dma_filter_fn, return as a fallback any free channel handled by the OMAP DMA engine driver. This feature is actively used by this driver and must be preserved. > Signed-off-by: Peter Ujfalusi > CC: Laurent Pinchart > CC: Mauro Carvalho Chehab > --- > Hi, > > the original patch was sent 29.04.2016: > https://patchwork.kernel.org/patch/8981811/ > > I have rebased it on top of linux-next. > > Regards, > Peter > > drivers/media/platform/omap3isp/isphist.c | 27 +++++++++------------------ > 1 file changed, 9 insertions(+), 18 deletions(-) > > diff --git a/drivers/media/platform/omap3isp/isphist.c > b/drivers/media/platform/omap3isp/isphist.c index > 7138b043a4aa..e163e3d92517 100644 > --- a/drivers/media/platform/omap3isp/isphist.c > +++ b/drivers/media/platform/omap3isp/isphist.c > @@ -18,7 +18,6 @@ > #include > #include > #include > -#include > #include > #include > > @@ -486,27 +485,19 @@ int omap3isp_hist_init(struct isp_device *isp) > hist->isp = isp; > > if (HIST_CONFIG_DMA) { > - struct platform_device *pdev = to_platform_device(isp->dev); > - struct resource *res; > - unsigned int sig = 0; > - dma_cap_mask_t mask; > - > - dma_cap_zero(mask); > - dma_cap_set(DMA_SLAVE, mask); > - > - res = platform_get_resource_byname(pdev, IORESOURCE_DMA, > - "hist"); > - if (res) > - sig = res->start; > - > - hist->dma_ch = dma_request_slave_channel_compat(mask, > - omap_dma_filter_fn, &sig, isp->dev, "hist"); > - if (!hist->dma_ch) > + hist->dma_ch = dma_request_chan(isp->dev, "hist"); > + if (IS_ERR(hist->dma_ch)) { > + ret = PTR_ERR(hist->dma_ch); > + if (ret == -EPROBE_DEFER) > + return ret; > + > + hist->dma_ch = NULL; > dev_warn(isp->dev, > "hist: DMA channel request failed, using PIO\n"); > - else > + } else { > dev_dbg(isp->dev, "hist: using DMA channel %s\n", > dma_chan_name(hist->dma_ch)); > + } > } > > hist->ops = &hist_ops; -- Regards, Laurent Pinchart