From: Arnd Bergmann <arnd@arndb.de> To: linux-arm-kernel@lists.infradead.org Cc: Sinan Kaya <okaya@codeaurora.org>, Abhijit Mahajan <abhijit.mahajan@avagotech.com>, Nagalakshmi Nandigama <nagalakshmi.nandigama@avagotech.com>, linux-scsi@vger.kernel.org, jcm@redhat.com, timur@codeaurora.org, "James E.J. Bottomley" <JBottomley@odin.com>, linux-kernel@vger.kernel.org, Sreekanth Reddy <sreekanth.reddy@avagotech.com>, Praveen Krishnamoorthy <praveen.krishnamoorthy@avagotech.com>, cov@codeaurora.org, linux-arm-msm@vger.kernel.org, agross@codeaurora.org, MPT-FusionLinux.pdl@avagotech.com, Hannes Reinecke <hare@suse.de> Subject: Re: [PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails Date: Tue, 10 Nov 2015 09:38:32 +0100 [thread overview] Message-ID: <5349261.sTnZTFhKWB@wuerfel> (raw) In-Reply-To: <56412AAE.80004@codeaurora.org> On Monday 09 November 2015 18:22:22 Sinan Kaya wrote: > On 11/9/2015 9:33 AM, Arnd Bergmann wrote: > > On Monday 09 November 2015 09:07:36 Sinan Kaya wrote: > >> On 11/9/2015 3:59 AM, Arnd Bergmann wrote: > > ioc->dma_mask is 0 and the driver is trying to use 32 bit even though 64 > bit supported by the platform. Ok, makes sense. > I think the proper fix is to pass the required_mask back to > consistent_dma_mask rather than using ioc->dma_mask and guessing. > > pci_set_consistent_dma_mask(pdev, required_mask) > > My code was just a band aid for broken code. > No, as Timur found, the driver is correct and it intentionally sets the 32-bit mask, and that is guaranteed to work on all sane hardware. Don't change the driver but find a better platform for your workload, or talk to the people that are responsible for the platform and get them to fix it. If the platform also doesn't have an IOMMU, you can probably work around it by setting up the dma-ranges property of the PCI host to map the low PCI addresses to the start of RAM. This will also require changes in the bootloader to set up the PCI outbound translation, and it will require implementing the DMA offset on ARM64, which I was hoping to avoid. Arnd
WARNING: multiple messages have this Message-ID (diff)
From: arnd@arndb.de (Arnd Bergmann) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails Date: Tue, 10 Nov 2015 09:38:32 +0100 [thread overview] Message-ID: <5349261.sTnZTFhKWB@wuerfel> (raw) In-Reply-To: <56412AAE.80004@codeaurora.org> On Monday 09 November 2015 18:22:22 Sinan Kaya wrote: > On 11/9/2015 9:33 AM, Arnd Bergmann wrote: > > On Monday 09 November 2015 09:07:36 Sinan Kaya wrote: > >> On 11/9/2015 3:59 AM, Arnd Bergmann wrote: > > ioc->dma_mask is 0 and the driver is trying to use 32 bit even though 64 > bit supported by the platform. Ok, makes sense. > I think the proper fix is to pass the required_mask back to > consistent_dma_mask rather than using ioc->dma_mask and guessing. > > pci_set_consistent_dma_mask(pdev, required_mask) > > My code was just a band aid for broken code. > No, as Timur found, the driver is correct and it intentionally sets the 32-bit mask, and that is guaranteed to work on all sane hardware. Don't change the driver but find a better platform for your workload, or talk to the people that are responsible for the platform and get them to fix it. If the platform also doesn't have an IOMMU, you can probably work around it by setting up the dma-ranges property of the PCI host to map the low PCI addresses to the start of RAM. This will also require changes in the bootloader to set up the PCI outbound translation, and it will require implementing the DMA offset on ARM64, which I was hoping to avoid. Arnd
next prev parent reply other threads:[~2015-11-10 8:38 UTC|newest] Thread overview: 86+ messages / expand[flat|nested] mbox.gz Atom feed top 2015-11-09 1:57 [PATCH V2 0/3] scsi: mptxsas: updates for ARM64 Sinan Kaya 2015-11-09 1:57 ` Sinan Kaya 2015-11-09 1:57 ` [PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails Sinan Kaya 2015-11-09 1:57 ` Sinan Kaya 2015-11-09 7:09 ` Hannes Reinecke 2015-11-09 7:09 ` Hannes Reinecke 2015-11-09 8:59 ` Arnd Bergmann 2015-11-09 8:59 ` Arnd Bergmann 2015-11-09 14:07 ` Sinan Kaya 2015-11-09 14:07 ` Sinan Kaya 2015-11-09 14:33 ` Arnd Bergmann 2015-11-09 14:33 ` Arnd Bergmann 2015-11-09 23:22 ` Sinan Kaya 2015-11-09 23:22 ` Sinan Kaya 2015-11-09 23:29 ` Timur Tabi 2015-11-09 23:29 ` Timur Tabi 2015-11-10 8:38 ` Arnd Bergmann [this message] 2015-11-10 8:38 ` Arnd Bergmann 2015-11-10 16:06 ` Sinan Kaya 2015-11-10 16:06 ` Sinan Kaya 2015-11-10 16:47 ` Arnd Bergmann 2015-11-10 16:47 ` Arnd Bergmann 2015-11-10 17:00 ` Timur Tabi 2015-11-10 17:00 ` Timur Tabi 2015-11-10 19:13 ` Arnd Bergmann 2015-11-10 19:13 ` Arnd Bergmann 2015-11-10 21:03 ` Timur Tabi 2015-11-10 21:03 ` Timur Tabi 2015-11-10 21:54 ` Arnd Bergmann 2015-11-10 21:54 ` Arnd Bergmann 2015-11-10 21:59 ` Timur Tabi 2015-11-10 21:59 ` Timur Tabi 2015-11-10 22:08 ` Arnd Bergmann 2015-11-10 22:08 ` Arnd Bergmann 2015-11-10 17:19 ` Sinan Kaya 2015-11-10 17:19 ` Sinan Kaya 2015-11-10 18:27 ` James Bottomley 2015-11-10 18:27 ` James Bottomley 2015-11-10 19:14 ` Sinan Kaya 2015-11-10 19:14 ` Sinan Kaya 2015-11-10 19:43 ` James Bottomley 2015-11-10 19:43 ` James Bottomley 2015-11-10 19:56 ` Sinan Kaya 2015-11-10 19:56 ` Sinan Kaya 2015-11-10 20:05 ` James Bottomley 2015-11-10 20:05 ` James Bottomley 2015-11-10 20:26 ` Sinan Kaya 2015-11-10 20:26 ` Sinan Kaya 2015-11-10 20:35 ` James Bottomley 2015-11-10 20:35 ` James Bottomley 2015-11-10 19:56 ` Arnd Bergmann 2015-11-10 19:56 ` Arnd Bergmann 2015-11-10 20:58 ` Sinan Kaya 2015-11-10 20:58 ` Sinan Kaya 2015-11-10 22:06 ` Arnd Bergmann 2015-11-10 22:06 ` Arnd Bergmann 2015-11-09 14:00 ` Sinan Kaya 2015-11-09 14:00 ` Sinan Kaya 2015-11-09 1:57 ` [PATCH V2 2/3] scsi: fix compiler warning for sg Sinan Kaya 2015-11-09 1:57 ` Sinan Kaya 2015-11-09 14:14 ` Andy Shevchenko 2015-11-09 14:14 ` Andy Shevchenko 2015-11-10 3:21 ` Sinan Kaya 2015-11-10 3:21 ` Sinan Kaya 2015-11-10 3:21 ` Sinan Kaya 2015-11-10 3:26 ` Timur Tabi 2015-11-10 3:26 ` Timur Tabi 2015-11-10 4:51 ` Sinan Kaya 2015-11-10 4:51 ` Sinan Kaya 2015-11-10 4:53 ` Timur Tabi 2015-11-10 4:53 ` Timur Tabi 2015-11-10 9:23 ` Andy Shevchenko 2015-11-10 9:23 ` Andy Shevchenko 2015-11-10 10:09 ` Arnd Bergmann 2015-11-10 10:09 ` Arnd Bergmann 2015-11-09 1:57 ` [PATCH V2 3/3] scsi: mptxsas: offload IRQ execution Sinan Kaya 2015-11-09 1:57 ` Sinan Kaya 2015-11-09 7:15 ` Hannes Reinecke 2015-11-09 7:15 ` Hannes Reinecke 2015-11-09 14:01 ` Sinan Kaya 2015-11-09 14:01 ` Sinan Kaya 2015-11-10 5:59 ` Sinan Kaya 2015-11-10 5:59 ` Sinan Kaya 2015-11-10 5:59 ` Sinan Kaya 2016-03-16 15:31 ` Christopher Covington 2016-03-16 15:31 ` Christopher Covington
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