Subject: Re: 2.6.34-rc3 : Badness at lib/dma-debug.c:820 during ibmvscsi init

From: Sachin Sant <[email-masked]>
Date: Fri, 02 Apr 2010 12:07:58 +0530

FUJITA Tomonori wrote:
> On Fri, 02 Apr 2010 10:48:55 +0530
> Sachin Sant <[email-masked]> wrote:
>
>   
>> 2.6.34-rc3 boot on a power5 box produces this badness message
>> during ibmvscsi initialization.
>>
>> ibmvscsi 30000003: Client reserve enabled
>> ibmvscsi 30000003: sent SRP login
>> ibmvscsi 30000003: SRP_LOGIN succeeded
>> ibmvscsi 30000003: DMA-API: device driver frees DMA memory with wrong function [device address=0x0000000000011520] [size=36 bytes] [mapped as scather-gather] [unmapped as single]
>>     
>
> ibmvscsi has been incompatible with the dma debug facility, I
> guess. The driver uses dma_unmap_single for buffers mapped via
> dma_map_sg. It works but it's the API violation.
>
> Does this patch work?
>   
Yes, this patch fixed the issue for me. Thanks

-Regards
-Sachin

> diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c
> index dc1bcbe..0856436 100644
> --- a/drivers/scsi/ibmvscsi/ibmvscsi.c
> +++ b/drivers/scsi/ibmvscsi/ibmvscsi.c
> @@ -322,16 +322,6 @@ static void set_srp_direction(struct scsi_cmnd *cmd,
>  		srp_cmd->buf_fmt = fmt;
>  }
>
> -static void unmap_sg_list(int num_entries,
> -		struct device *dev,
> -		struct srp_direct_buf *md)
> -{
> -	int i;
> -
> -	for (i = 0; i < num_entries; ++i)
> -		dma_unmap_single(dev, md[i].va, md[i].len, DMA_BIDIRECTIONAL);
> -}
> -
>  /**
>   * unmap_cmd_data: - Unmap data pointed in srp_cmd based on the format
>   * @cmd:	srp_cmd whose additional_data member will be unmapped
> @@ -349,24 +339,9 @@ static void unmap_cmd_data(struct srp_cmd *cmd,
>
>  	if (out_fmt == SRP_NO_DATA_DESC && in_fmt == SRP_NO_DATA_DESC)
>  		return;
> -	else if (out_fmt == SRP_DATA_DESC_DIRECT ||
> -		 in_fmt == SRP_DATA_DESC_DIRECT) {
> -		struct srp_direct_buf *data =
> -			(struct srp_direct_buf *) cmd->add_data;
> -		dma_unmap_single(dev, data->va, data->len, DMA_BIDIRECTIONAL);
> -	} else {
> -		struct srp_indirect_buf *indirect =
> -			(struct srp_indirect_buf *) cmd->add_data;
> -		int num_mapped = indirect->table_desc.len /
> -			sizeof(struct srp_direct_buf);
>
> -		if (num_mapped <= MAX_INDIRECT_BUFS) {
> -			unmap_sg_list(num_mapped, dev, &indirect->desc_list[0]);
> -			return;
> -		}
> -
> -		unmap_sg_list(num_mapped, dev, evt_struct->ext_list);
> -	}
> +	if (evt_struct->cmnd)
> +		scsi_dma_unmap(evt_struct->cmnd);
>  }
>
>  static int map_sg_list(struct scsi_cmnd *cmd, int nseg,
>
>   

-- 

---------------------------------
Sachin Sant
IBM Linux Technology Center
India Systems and Technology Labs
Bangalore, India
---------------------------------