From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758359AbZELMka (ORCPT ); Tue, 12 May 2009 08:40:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753050AbZELMkP (ORCPT ); Tue, 12 May 2009 08:40:15 -0400 Received: from moutng.kundenserver.de ([212.227.126.188]:52063 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751270AbZELMkN convert rfc822-to-8bit (ORCPT ); Tue, 12 May 2009 08:40:13 -0400 From: Arnd Bergmann To: Jeff Garzik Subject: Re: [PATCH] ata: libata depends on HAS_DMA Date: Tue, 12 May 2009 14:40:08 +0200 User-Agent: KMail/1.9.9 Cc: linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org References: <20090511222702.352192505@arndb.de> <200905112238.55404.arnd@arndb.de> <4A08C9C0.6040202@pobox.com> In-Reply-To: <4A08C9C0.6040202@pobox.com> X-Face: I@=L^?./?$U,EK.)V[4*>`zSqm0>65YtkOe>TFD'!aw?7OVv#~5xd\s,[~w]-J!)|%=]>=?utf-8?q?+=0A=09=7EohchhkRGW=3F=7C6=5FqTmkd=5Ft=3FLZC=23Q-=60=2E=60Y=2Ea=5E?= =?utf-8?q?3zb?=) =?utf-8?q?+U-JVN=5DWT=25cw=23=5BYo0=267C=26bL12wWGlZi=0A=09=7EJ=3B=5Cwg?= =?utf-8?q?=3B3zRnz?=,J"CT_)=\H'1/{?SR7GDu?WIopm.HaBG=QYj"NZD_[zrM\Gip^U MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8BIT Content-Disposition: inline Message-Id: <200905121440.09315.arnd@arndb.de> X-Provags-ID: V01U2FsdGVkX18qK67kMFouM/hIxufkeCQkYtPqpW9M4JKLwe5 ZPrWJyRGfGj+m6612gMjWuDxbMwwNMdo2ZoKlngmwtZYmy9tS0 kSy57Tq0kVVm43c1PRCdA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday 12 May 2009, Jeff Garzik wrote: > > --- a/drivers/ata/Kconfig > > +++ b/drivers/ata/Kconfig > > @@ -4,7 +4,7 @@ > >   > >  menuconfig ATA > >       tristate "Serial ATA (prod) and Parallel ATA (experimental) drivers" > > -     depends on HAS_IOMEM > > +     depends on HAS_IOMEM && HAS_DMA > >       depends on BLOCK > >       depends on !(M32R || M68K) || BROKEN > > What specifically is breaking? > > Ideally we should be able to work with PIO-only... CONFIG_HAS_DMA is not set on architectures that are missing asm/dma-mapping.h or fall back to asm-generic/dma-mapping-broken.h. In the latter case, you get a link error: drivers/built-in.o: In function `sas_issue_ata_cmd': /home/arnd/linux/linux-2.6/drivers/scsi/libsas/sas_ata.c(.text+0x33c50): undefined reference to `dma_map_sg' /home/arnd/linux/linux-2.6/drivers/scsi/libsas/sas_ata.c(.text+0x33ef0): undefined reference to `dma_unmap_sg' drivers/built-in.o: In function `ata_sg_clean': /home/arnd/linux/linux-2.6/drivers/ata/libata-core.c(.text+0x37d18): undefined reference to `dma_unmap_sg' drivers/built-in.o: In function `ata_qc_issue': /home/arnd/linux/linux-2.6/drivers/ata/libata-core.c(.text+0x38774): undefined reference to `dma_map_sg' drivers/built-in.o: In function `ata_port_start': /home/arnd/linux/linux-2.6/drivers/ata/libata-core.c(.text+0x3bf0c): undefined reference to `dmam_alloc_coherent' A slightly less naive (but still suboptimal) fix would be the patch below. I could not find an easy way to force all devices to use PIO, this patch would simply fail if someone tried to set a DMA mode. Arnd <>< --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -4629,6 +4629,7 @@ static unsigned int ata_dev_init_params(struct ata_device *dev, */ void ata_sg_clean(struct ata_queued_cmd *qc) { +#ifdef CONFIG_HAS_DMA struct ata_port *ap = qc->ap; struct scatterlist *sg = qc->sg; int dir = qc->dma_dir; @@ -4642,6 +4643,7 @@ void ata_sg_clean(struct ata_queued_cmd *qc) qc->flags &= ~ATA_QCFLAG_DMAMAP; qc->sg = NULL; +#endif /* CONFIG_HAS_DMA */ } /** @@ -4743,6 +4745,7 @@ void ata_sg_init(struct ata_queued_cmd *qc, struct scatterlist *sg, */ static int ata_sg_setup(struct ata_queued_cmd *qc) { +#ifdef CONFIG_HAS_DMA struct ata_port *ap = qc->ap; unsigned int n_elem; @@ -4758,6 +4761,10 @@ static int ata_sg_setup(struct ata_queued_cmd *qc) qc->flags |= ATA_QCFLAG_DMAMAP; return 0; +#else + DPRINTK("attempted to use DMA on incompatible architecture\n"); + return -EINVAL; +#endif /* CONFIG_HAS_DMA */ } /** @@ -5450,8 +5457,12 @@ int ata_port_start(struct ata_port *ap) { struct device *dev = ap->dev; +#ifdef CONFIG_HAS_DMA ap->prd = dmam_alloc_coherent(dev, ATA_PRD_TBL_SZ, &ap->prd_dma, GFP_KERNEL); +#else + ap->prd = devres_alloc(dev, ATA_PRD_TBL_SZ, GFP_KERNEL); +#endif /* CONFIG_HAS_DMA */ if (!ap->prd) return -ENOMEM; diff --git a/drivers/scsi/libsas/Kconfig b/drivers/scsi/libsas/Kconfig index 59e00fa..e00271f 100644 --- a/drivers/scsi/libsas/Kconfig +++ b/drivers/scsi/libsas/Kconfig @@ -34,6 +34,7 @@ config SCSI_SAS_ATA bool "ATA support for libsas (requires libata)" depends on SCSI_SAS_LIBSAS depends on ATA = y || ATA = SCSI_SAS_LIBSAS + depends on HAS_DMA help Builds in ATA support into libsas. Will necessitate the loading of libata along with libsas.