From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [PATCH 1/3] RFC: AHCI: libahci is missing DMA Date: Wed, 04 Dec 2013 16:47:31 +0400 Message-ID: <529F2463.8080907@cogentembedded.com> References: <1386159055-10264-1-git-send-email-oliver@schinagl.nl> <1386159055-10264-2-git-send-email-oliver@schinagl.nl> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1386159055-10264-2-git-send-email-oliver@schinagl.nl> Sender: linux-ide-owner@vger.kernel.org To: oliver@schinagl.nl, tj@kernel.org, grant.likely@linaro.org, ob.herring@calxeda.com, linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, dev@linux-sunxi.org Cc: maxime.ripard@free-electrons.com, ijc@hellion.org.uk, hdegoede@redhat.com, oliver+list@schinagl.nl List-Id: devicetree@vger.kernel.org Hello. On 04-12-2013 16:10, oliver@schinagl.nl wrote: > From: Oliver Schinagl > The Allwinner sunxi platforms have patched in the following to enable > DMA. This patch enables DMA controllers for the SUNXI Architecture. > Signed-off-by: Olliver Schinagl > --- > drivers/ata/ahci.h | 6 ++++++ > drivers/ata/libahci.c | 8 ++++++++ > 2 files changed, 14 insertions(+) > diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h > index 2289efdf..2bf2423 100644 > --- a/drivers/ata/ahci.h > +++ b/drivers/ata/ahci.h [...] > @@ -209,6 +210,11 @@ enum { > PORT_DEVSLP_DSP = (1 << 1), /* DevSlp present */ > PORT_DEVSLP_ADSE = (1 << 0), /* Aggressive DevSlp enable */ > > + /* PORT_DMA bits */ > + PORT_DMA_SETUP_OFFSET = 8, /* dma setup offset */ > + PORT_DMA_SETUP_MASK = (0xff << PORT_DMA_SETUP_OFFSET),/* dma mask */ > + PORT_DMA_SETUP_INIT = (0x44 << 0), Why not shift it right by PORT_DMA_SETUP_OFFSET if you do it in the next file anyway? [...] > diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c > index c482f8c..d697a74 100644 > --- a/drivers/ata/libahci.c > +++ b/drivers/ata/libahci.c > @@ -570,6 +570,14 @@ void ahci_start_engine(struct ata_port *ap) > void __iomem *port_mmio = ahci_port_base(ap); > u32 tmp; > > +#ifdef CONFIG_ARCH_SUNXI > + /* Setup DMA before DMA start */ > + tmp = readl(port_mmio + PORT_DMA); > + tmp &= ~PORT_DMA_SETUP_MASK; > + tmp |= PORT_DMA_SETUP_INIT << PORT_DMA_SETUP_OFFSET; > + writel(tmp, port_mmio + PORT_DMA); > +#endif > + I don't think #ifdef is appropriate here. WBR, Sergei