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From: arnd@arndb•de (Arnd Bergmann)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v3 1/4] dmaengine: mmp-pdma support
Date: Tue, 14 Aug 2012 09:33:25 +0000	[thread overview]
Message-ID: <201208140933.26061.arnd@arndb.de> (raw)
In-Reply-To: <1344917519-9505-2-git-send-email-zhangfei.gao@marvell.com>

On Tuesday 14 August 2012, Zhangfei Gao wrote:
> 1. virtual channel vs. physical channel
> Virtual channel is managed by dmaengine
> Physical channel handling resource, such as irq
> Physical channel is alloced dynamically as descending priority,
> freed immediately when irq done.
> The availble highest priority physically channel will alwayes be alloced
> 
> Issue pending list -> alloc highest dma physically channel available -> dma done -> free physically channel
> 
> 2. list: running list & pending list
> submit: desc list -> pending list
> issue_pending_list: if (IDLE) pending list -> running list; free pending list (RUN)
> irq: free running list (IDLE)
>      check pendlist -> pending list -> running list; free pending list (RUN)
> 
> 3. irq:
> Each list generate one irq, calling callback
> One list may contain several desc chain, in such case, make sure only the last desc list generate irq.
> 
> 4. async
> Submit will add desc chain to pending list, which can be multi-called
> If multi desc chain is submitted, only the last desc would generate irq -> call back
> If IDLE, issue_pending_list start pending_list, transforming pendlist to running list
> If RUN, irq will start pending list
> 
> 5. test
> 5.1 pxa3xx_nand on pxa910
> 5.2 insmod dmatest.ko (threads_per_chan=y)
> By default drivers/dma/dmatest.c test every channel and test memcpy with 1 threads per channel
> 
> Signed-off-by: Zhangfei Gao <zhangfei.gao@marvell•com>

Acked-by: Arnd Bergmann <arnd@arndb•de>

  parent reply	other threads:[~2012-08-14  9:33 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-08-14  4:11 [PATCH v3 0/4] dmaengine: add support mmp-pdma Zhangfei Gao
2012-08-14  4:11 ` [PATCH v3 1/4] dmaengine: mmp-pdma support Zhangfei Gao
2012-08-14  8:30   ` Russell King - ARM Linux
2012-08-15  7:44     ` zhangfei gao
2012-08-15  8:04       ` Russell King - ARM Linux
2012-08-15  9:09         ` zhangfei gao
2012-08-14  9:33   ` Arnd Bergmann [this message]
2012-08-14  4:11 ` [PATCH v3 2/4] dmaengine: mmp_tdma: add dt support Zhangfei Gao
2012-08-14  9:34   ` Arnd Bergmann
2012-08-15  7:47     ` zhangfei gao
2012-08-14  4:11 ` [PATCH v3 3/4] dmatest: add dmaengine_slave_config for DMA_MEMCPY Zhangfei Gao
2012-08-14  8:20   ` Russell King - ARM Linux
2012-08-15  7:29     ` zhangfei gao
2012-08-14  4:11 ` [PATCH v3 4/4] mtd: pxa3xx-nand: replace pxa_request_dma with dmaengine Zhangfei Gao

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