From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-vw0-f204.google.com (mail-vw0-f204.google.com [209.85.212.204]) by ozlabs.org (Postfix) with ESMTP id 133B1B7BA4 for ; Fri, 16 Oct 2009 12:25:16 +1100 (EST) Received: by vws42 with SMTP id 42so748778vws.17 for ; Thu, 15 Oct 2009 18:25:15 -0700 (PDT) MIME-Version: 1.0 Sender: dan.j.williams@gmail.com In-Reply-To: <1255588866-4133-1-git-send-email-Vishnu@freescale.com> References: <1255588866-4133-1-git-send-email-Vishnu@freescale.com> Date: Thu, 15 Oct 2009 18:25:14 -0700 Message-ID: Subject: Re: [PATCH v0 1/2] DMA: fsldma: Disable DMA_INTERRUPT when Async_tx enabled From: Dan Williams To: Vishnu Suresh Content-Type: text/plain; charset=ISO-8859-1 Cc: herbert@gondor.apana.org.au, linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, linuxppc-dev@ozlabs.org, linux-crypto@vger.kernel.org, Timur Tabi List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , [ added Leo and Timur to the Cc ] On Wed, Oct 14, 2009 at 11:41 PM, Vishnu Suresh wrot= e: > This patch disables the use of DMA_INTERRUPT capability with Async_tx > > The fsldma produces a null transfer with DMA_INTERRUPT > capability when used with Async_tx. When RAID devices queue > a transaction via Async_tx, this =A0results in a hang. > > Signed-off-by: Vishnu Suresh > --- > =A0drivers/dma/fsldma.c | =A0 =A06 ++++++ > =A01 files changed, 6 insertions(+), 0 deletions(-) > > diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c > index 296f9e7..66d9b39 100644 > --- a/drivers/dma/fsldma.c > +++ b/drivers/dma/fsldma.c > @@ -1200,7 +1200,13 @@ static int __devinit of_fsl_dma_probe(struct of_de= vice *dev, > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 = =A0 =A0 =A0 =A0 =A0 =A0- fdev->reg.start + 1); > > =A0 =A0 =A0 =A0dma_cap_set(DMA_MEMCPY, fdev->common.cap_mask); > +#ifndef CONFIG_ASYNC_CORE > + =A0 =A0 =A0 /* > + =A0 =A0 =A0 =A0* The DMA_INTERRUPT async_tx is a NULL transfer, which w= ill > + =A0 =A0 =A0 =A0* triger a PE interrupt. > + =A0 =A0 =A0 =A0*/ > =A0 =A0 =A0 =A0dma_cap_set(DMA_INTERRUPT, fdev->common.cap_mask); > +#endif > =A0 =A0 =A0 =A0dma_cap_set(DMA_SLAVE, fdev->common.cap_mask); > =A0 =A0 =A0 =A0fdev->common.device_alloc_chan_resources =3D fsl_dma_alloc= _chan_resources; > =A0 =A0 =A0 =A0fdev->common.device_free_chan_resources =3D fsl_dma_free_c= han_resources; You are basically saying that fsl_dma_prep_interrupt() is buggy. Can that routine be fixed rather than this piecemeal solution? If it cannot be fixed (i.e. hardware issue) then fsl_dma_prep_interrupt() should just be disabled/deleted altogether. -- Dan