Re: [PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails

On 11/10/2015 3:38 AM, Arnd Bergmann wrote: > 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

Re: [PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails

On Tuesday 10 November 2015 11:06:40 Sinan Kaya wrote: > On 11/10/2015 3:38 AM, Arnd Bergmann wrote: > > 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

Re: [PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails

On 11/10/2015 10:47 AM, Arnd Bergmann wrote: What BenH was worried about here is that the driver sets different masks for streaming and coherent mappings, which is indeed a worry that could hit us on ARM as well, but I suppose we'll have to deal with that in platform code. Setting both masks to

Re: [PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails

On Tuesday 10 November 2015 11:00:59 Timur Tabi wrote: > On 11/10/2015 10:47 AM, Arnd Bergmann wrote: > > What BenH was worried about here is that the driver sets different masks > > for streaming and coherent mappings, which is indeed a worry that > > could hit us on ARM as well, but I suppose

Re: [PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails

On 11/10/2015 1:27 PM, James Bottomley wrote: On Tue, 2015-11-10 at 12:19 -0500, Sinan Kaya wrote: On 11/10/2015 11:47 AM, Arnd Bergmann wrote: On Tuesday 10 November 2015 11:06:40 Sinan Kaya wrote: On 11/10/2015 3:38 AM, Arnd Bergmann wrote: From the email thread, it looks like this was

Re: [PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails

On Tue, 2015-11-10 at 12:19 -0500, Sinan Kaya wrote: > On 11/10/2015 11:47 AM, Arnd Bergmann wrote: > > On Tuesday 10 November 2015 11:06:40 Sinan Kaya wrote: > >> On 11/10/2015 3:38 AM, Arnd Bergmann wrote: > >> From the email thread, it looks like this was introduced to support > >> some

Re: [PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails

On 11/10/2015 11:47 AM, Arnd Bergmann wrote: On Tuesday 10 November 2015 11:06:40 Sinan Kaya wrote: On 11/10/2015 3:38 AM, Arnd Bergmann wrote: > 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

Re: [PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails

On Tue, 2015-11-10 at 14:14 -0500, Sinan Kaya wrote: > > On 11/10/2015 1:27 PM, James Bottomley wrote: > > On Tue, 2015-11-10 at 12:19 -0500, Sinan Kaya wrote: > >> On 11/10/2015 11:47 AM, Arnd Bergmann wrote: > >>> On Tuesday 10 November 2015 11:06:40 Sinan Kaya wrote: > On 11/10/2015 3:38

Re: [PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails

On Tue, 2015-11-10 at 14:56 -0500, Sinan Kaya wrote: > > On 11/10/2015 2:43 PM, James Bottomley wrote: > > The Issue, as stated by LSI is > > > > Initially set the consistent DMA mask to 32 bit and then change > > it > > to 64 bit mask after allocating RDPQ pools by

Re: [PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails

On 11/10/2015 3:05 PM, James Bottomley wrote: OK, you don't seem to be understanding the problem: the Altix isn't a LSI card, it was a SGI platform. Got it. It was the platform where we first discovered the issue that a lot of storage cards didn't work because it by default had no memory

Re: [PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails

On 11/10/2015 2:43 PM, James Bottomley wrote: The Issue, as stated by LSI is Initially set the consistent DMA mask to 32 bit and then change it to 64 bit mask after allocating RDPQ pools by calling the function _base_change_consistent_dma_mask.

Re: [PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails

On Tuesday 10 November 2015 12:19:33 Sinan Kaya wrote: > On 11/10/2015 11:47 AM, Arnd Bergmann wrote: > > On Tuesday 10 November 2015 11:06:40 Sinan Kaya wrote: > >> On 11/10/2015 3:38 AM, Arnd Bergmann wrote: > >> > No, as Timur found, the driver is correct and it intentionally > >>> sets the

Re: [PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails

On Tue, 2015-11-10 at 15:26 -0500, Sinan Kaya wrote: > > On 11/10/2015 3:05 PM, James Bottomley wrote: > > OK, you don't seem to be understanding the problem: the Altix isn't a > > LSI card, it was a SGI platform. > > Got it. > > > It was the platform where we first > > discovered the issue

Re: [PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails

On 11/10/2015 01:13 PM, Arnd Bergmann wrote: If the mask is 64-bit by default on ARM64, that is a bug that we need to fix urgently. Can you verify this? I think the mask is 0 by default, because there's no code in ARM64 that actually sets the mask. Take a look at arch_setup_pdev_archdata()

Re: [PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails

On 11/10/2015 2:56 PM, Arnd Bergmann wrote: The ACPI IORT table declares whether you enable IOMMU for a particular >device or not. The placement of IOMMU HW is system specific. The IORT >table gives the IOMMU HW topology to the operating system. This sounds odd. Clearly you need to specify

Re: [PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails

On 11/10/2015 03:54 PM, Arnd Bergmann wrote: In our drivers for 32-bit devices, we have to explicitly set the DMA mask to 32-bits in order to get any DMA working. Do you mean PCI devices or platform devices? Platform. Maybe the parent bus is lacking a dma-ranges property? All of this

Re: [PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails

On Tuesday 10 November 2015 15:58:19 Sinan Kaya wrote: > > On 11/10/2015 2:56 PM, Arnd Bergmann wrote: > >> The ACPI IORT table declares whether you enable IOMMU for a particular > >> >device or not. The placement of IOMMU HW is system specific. The IORT > >> >table gives the IOMMU HW topology to

Re: [PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails

On Tuesday 10 November 2015 15:59:18 Timur Tabi wrote: > On 11/10/2015 03:54 PM, Arnd Bergmann wrote: > > >> In our drivers for 32-bit devices, we have to explicitly set the DMA > >> mask to 32-bits in order to get any DMA working. > > > > Do you mean PCI devices or platform devices? > >

Re: [PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails

On 11/9/2015 2:09 AM, Hannes Reinecke wrote: On 11/09/2015 02:57 AM, Sinan Kaya wrote: Current code gives up when 32 bit DMA is not supported. This problem has been observed on systems without any memory below 4 gig. This patch tests 64 bit support before bailing out to find a working

Re: [PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails

On 11/9/2015 3:59 AM, Arnd Bergmann wrote: On Monday 09 November 2015 08:09:39 Hannes Reinecke wrote: On 11/09/2015 02:57 AM, Sinan Kaya wrote: Current code gives up when 32 bit DMA is not supported. This problem has been observed on systems without any memory below 4 gig. This patch tests

Re: [PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails

On Monday 09 November 2015 08:09:39 Hannes Reinecke wrote: > On 11/09/2015 02:57 AM, Sinan Kaya wrote: > > Current code gives up when 32 bit DMA is not supported. > > This problem has been observed on systems without any > > memory below 4 gig. > > > > This patch tests 64 bit support before

Re: [PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails

On 11/09/2015 05:22 PM, Sinan Kaya wrote: if (ioc->dma_mask) consistent_dma_mask = DMA_BIT_MASK(64); else consistent_dma_mask = DMA_BIT_MASK(32); <-- why here? So this change is from this patch: http://permalink.gmane.org/gmane.linux.kernel/1759343 Note that this was

[PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails

Current code gives up when 32 bit DMA is not supported. This problem has been observed on systems without any memory below 4 gig. This patch tests 64 bit support before bailing out to find a working combination. Signed-off-by: Sinan Kaya ---

Re: [PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails

On 11/09/2015 02:57 AM, Sinan Kaya wrote: > Current code gives up when 32 bit DMA is not supported. > This problem has been observed on systems without any > memory below 4 gig. > > This patch tests 64 bit support before bailing out to find > a working combination. > That feels decidedly odd.