From mboxrd@z Thu Jan 1 00:00:00 1970 From: Subhash Jadavani Subject: ARM DMA: Fix in dma_cache_maint_page Date: Wed, 16 Jan 2013 18:17:08 +0530 Message-ID: <50F6A14C.6040206@codeaurora.org> References: <50F69F72.4030807@codeaurora.org> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============7860530804503054250==" Return-path: In-Reply-To: <50F69F72.4030807@codeaurora.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Russell King , linux-arm-kernel@lists.infradead.org Cc: james.bottomley@hansenpartnership.com, "linux-arm-msm@vger.kernel.org" List-Id: linux-arm-msm@vger.kernel.org This is a multi-part message in MIME format. --===============7860530804503054250== Content-Type: multipart/alternative; boundary="------------040704020809070909090107" This is a multi-part message in MIME format. --------------040704020809070909090107 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Hi Russell, Is it possible to pick up James patch below? Thread here: http://comments.gmane.org/gmane.linux.kernel.mmc/18670, have the details on the motivation behind this fix. Regards, Subhash -------- Original Message -------- Subject: Re: [PATCH v2 1/1] block: blk-merge: don't merge the pages with non-contiguous descriptors Date: Wed, 16 Jan 2013 18:09:14 +0530 From: Subhash Jadavani To: James Bottomley CC: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, linux-mmc@vger.kernel.org, linux-arm-msm@vger.kernel.org, martin.petersen@oracle.com, asias@redhat.com, tj@kernel.org, linux-arm-kernel@lists.infradead.org, Russell King On 1/16/2013 4:02 PM, James Bottomley wrote: > On Wed, 2013-01-16 at 12:07 +0530, Subhash Jadavani wrote: > >> Now consider this call stack from MMC block driver (this is on the ARmv7 >> based board): >> [ 98.918174] [] (v7_dma_inv_range+0x30/0x48) from >> [] (dma_cache_maint_page+0x1c4/0x24c) >> [ 98.927819] [] (dma_cache_maint_page+0x1c4/0x24c) from >> [] (___dma_page_cpu_to_dev+0x14/0x1c) >> [ 98.937982] [] (___dma_page_cpu_to_dev+0x14/0x1c) from >> [] (dma_map_sg+0x3c/0x114) > OK, so this is showing that ARM itself is making the assumption that the > pages are contiguous in the page offset map. > > Fix this by doing the increment via the pfn, which will do the right > thing whatever the memory model. > > Signed-off-by: James Bottomley Thanks James. Yes, it make sense to fix the ARM code itself if it is the only one giving this trouble. I have tried your change below and it also fixes this issue (without having my blk-merge patch). I will forward your change to Russel King to see what he thinks about it. Regards, Subhash > > --- > > diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c > index 6b2fb87..ab88c5b 100644 > --- a/arch/arm/mm/dma-mapping.c > +++ b/arch/arm/mm/dma-mapping.c > @@ -809,7 +809,7 @@ static void dma_cache_maint_page(struct page *page, unsigned long offset, > op(vaddr, len, dir); > } > offset = 0; > - page++; > + page = pfn_to_page(page_to_pfn(page) + 1); > left -= len; > } while (left); > } > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-scsi" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html --------------040704020809070909090107 Content-Type: text/html; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit
Hi Russell,

Is it possible to pick up James patch below? Thread here: http://comments.gmane.org/gmane.linux.kernel.mmc/18670, have the details on the motivation behind this fix.

Regards,
Subhash

-------- Original Message --------
Subject: Re: [PATCH v2 1/1] block: blk-merge: don't merge the pages with non-contiguous descriptors
Date: Wed, 16 Jan 2013 18:09:14 +0530
From: Subhash Jadavani <subhashj@codeaurora.org>
To: James Bottomley <James.Bottomley@HansenPartnership.com>
CC: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, linux-mmc@vger.kernel.org, linux-arm-msm@vger.kernel.org, martin.petersen@oracle.com, asias@redhat.com, tj@kernel.org, linux-arm-kernel@lists.infradead.org, Russell King <linux@arm.linux.org.uk> 


On 1/16/2013 4:02 PM, James Bottomley wrote:
> On Wed, 2013-01-16 at 12:07 +0530, Subhash Jadavani wrote:
>
>> Now consider this call stack from MMC block driver (this is on the ARmv7
>> based board):
>>       [   98.918174] [<c001b50c>] (v7_dma_inv_range+0x30/0x48) from
>> [<c0017b8c>] (dma_cache_maint_page+0x1c4/0x24c)
>>       [   98.927819] [<c0017b8c>] (dma_cache_maint_page+0x1c4/0x24c) from
>> [<c0017c28>] (___dma_page_cpu_to_dev+0x14/0x1c)
>>       [   98.937982] [<c0017c28>] (___dma_page_cpu_to_dev+0x14/0x1c) from
>> [<c0017ff8>] (dma_map_sg+0x3c/0x114)
> OK, so this is showing that ARM itself is making the assumption that the
> pages are contiguous in the page offset map.
>
> Fix this by doing the increment via the pfn, which will do the right
> thing whatever the memory model.
>
> Signed-off-by: James Bottomley <JBottomley@Parallels.com>

Thanks James. Yes, it make sense to fix the ARM code itself if it is the 
only one giving this trouble.
I have tried your change below and it also fixes this issue (without 
having my blk-merge patch). I will forward your change to Russel King to 
see what he thinks about it.

Regards,
Subhash
>
> ---
>
> diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
> index 6b2fb87..ab88c5b 100644
> --- a/arch/arm/mm/dma-mapping.c
> +++ b/arch/arm/mm/dma-mapping.c
> @@ -809,7 +809,7 @@ static void dma_cache_maint_page(struct page *page, unsigned long offset,
>   			op(vaddr, len, dir);
>   		}
>   		offset = 0;
> -		page++;
> +		page = pfn_to_page(page_to_pfn(page) + 1);
>   		left -= len;
>   	} while (left);
>   }
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html


--------------040704020809070909090107-- --===============7860530804503054250== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel --===============7860530804503054250==-- From mboxrd@z Thu Jan 1 00:00:00 1970 From: subhashj@codeaurora.org (Subhash Jadavani) Date: Wed, 16 Jan 2013 18:17:08 +0530 Subject: ARM DMA: Fix in dma_cache_maint_page In-Reply-To: <50F69F72.4030807@codeaurora.org> References: <50F69F72.4030807@codeaurora.org> Message-ID: <50F6A14C.6040206@codeaurora.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Russell, Is it possible to pick up James patch below? Thread here: http://comments.gmane.org/gmane.linux.kernel.mmc/18670, have the details on the motivation behind this fix. Regards, Subhash -------- Original Message -------- Subject: Re: [PATCH v2 1/1] block: blk-merge: don't merge the pages with non-contiguous descriptors Date: Wed, 16 Jan 2013 18:09:14 +0530 From: Subhash Jadavani To: James Bottomley CC: linux-kernel at vger.kernel.org, linux-scsi at vger.kernel.org, linux-mmc at vger.kernel.org, linux-arm-msm at vger.kernel.org, martin.petersen at oracle.com, asias at redhat.com, tj at kernel.org, linux-arm-kernel at lists.infradead.org, Russell King On 1/16/2013 4:02 PM, James Bottomley wrote: > On Wed, 2013-01-16 at 12:07 +0530, Subhash Jadavani wrote: > >> Now consider this call stack from MMC block driver (this is on the ARmv7 >> based board): >> [ 98.918174] [] (v7_dma_inv_range+0x30/0x48) from >> [] (dma_cache_maint_page+0x1c4/0x24c) >> [ 98.927819] [] (dma_cache_maint_page+0x1c4/0x24c) from >> [] (___dma_page_cpu_to_dev+0x14/0x1c) >> [ 98.937982] [] (___dma_page_cpu_to_dev+0x14/0x1c) from >> [] (dma_map_sg+0x3c/0x114) > OK, so this is showing that ARM itself is making the assumption that the > pages are contiguous in the page offset map. > > Fix this by doing the increment via the pfn, which will do the right > thing whatever the memory model. > > Signed-off-by: James Bottomley Thanks James. Yes, it make sense to fix the ARM code itself if it is the only one giving this trouble. I have tried your change below and it also fixes this issue (without having my blk-merge patch). I will forward your change to Russel King to see what he thinks about it. Regards, Subhash > > --- > > diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c > index 6b2fb87..ab88c5b 100644 > --- a/arch/arm/mm/dma-mapping.c > +++ b/arch/arm/mm/dma-mapping.c > @@ -809,7 +809,7 @@ static void dma_cache_maint_page(struct page *page, unsigned long offset, > op(vaddr, len, dir); > } > offset = 0; > - page++; > + page = pfn_to_page(page_to_pfn(page) + 1); > left -= len; > } while (left); > } > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-scsi" in > the body of a message to majordomo at vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo at vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html -------------- next part -------------- An HTML attachment was scrubbed... URL: