lkml.org 
[lkml]   [2012]   [Jan]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v2 1/2] dmaengine: Add support for per xfer specific privatedata & box dma
On 1/17/2012 7:23 PM, Vinod Koul wrote:
> On Fri, 2012-01-06 at 18:17 +0530, Ravi Kumar V wrote:
>>
>> diff --git a/include/asm-generic/scatterlist.h b/include/asm-generic/scatterlist.h
>> index 5de0735..e66dfcb 100644
>> --- a/include/asm-generic/scatterlist.h
>> +++ b/include/asm-generic/scatterlist.h
>> @@ -14,6 +14,7 @@ struct scatterlist {
>> #ifdef CONFIG_NEED_SG_DMA_LENGTH
>> unsigned int dma_length;
>> #endif
>> + unsigned long private_data;
> what do you plan to pass here. Please keep in mind this is a generic
> scatterlist structure, and modifying it for your purposes doesn't seem
> to be a great one!
> Also why can't you pass this as addition argument in your new "BOX API"?
We are using DMA-Engine framework for both SG mode and BOX mode of our HW.
For SG mode we are using device_prep_dma_sg API but the problem we are
facing is we need to pass command configuration parameter along with
each descriptor to our HW, we did not find any suitable API/structure in
framework to support this.
So thought of adding new element in struct scatterlist.
please can you suggest a way to pass private parameter with
every descriptor.
>
>> };
>>
>> /*
>> +
>> +struct dma_box_list {
>> + dma_addr_t dma_row_address;
>> + unsigned int dma_row_len;
>> + unsigned int dma_row_num;
>> + unsigned int dma_row_offset;
>> + unsigned long private_data;
>> +};
> again a private data here?
> is this some kind of interleaved pattern?
Yes this interleaved pattern.
>> +
>> /**
>> * struct dma_device - info on the entity supplying DMA services
>> * @chancnt: how many DMA channels are supported
>> @@ -497,6 +507,11 @@ struct dma_device {
>> struct dma_async_tx_descriptor *(*device_prep_dma_cyclic)(
>> struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
>> size_t period_len, enum dma_data_direction direction);
>> + struct dma_async_tx_descriptor *(*device_prep_dma_box)(
>> + struct dma_chan *chan, struct dma_box_list *dst_box,
>> + struct dma_box_list *src_box, unsigned int num_list,
>> + unsigned long flags);
> still not clean what kind of transfer do you want to do here
We are doing interleaved pattern of data transfer between source and
destination boxs, num_list is number of box mode commands
Please can you refer patch 0/2 I have replied explaining about box mode
transfer clearly.
>> +
>> int (*device_control)(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
>> unsigned long arg);
>>
>
>


--
Sent by a consultant of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.


\
 
 \ /
  Last update: 2012-01-20 13:37    [W:0.068 / U:3.280 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site