Re: [PATCH] dma: add new DMA control commands
From: Huang Shijie
Date: Thu Oct 18 2012 - 02:42:20 EST
ä 2012å10æ18æ 14:18, Vinod Koul åé:
Why cant you do start (prepare clock etc) when you submit the descriptorI ever thought this method too.
to dmaengine. Can be done in tx_submit callback.
Similarly remove the clock when dma transaction gets completed.
But it will become low efficient in the following case:
Assuming the gpmi-nand driver has to read out 1024 pages in one
_SINGLE_ read operation.
The gpmi-nand will submit the descriptor to dmaengine per page. So with
the system will repeat the enable/disable dma clock 1024 time. At every
enable/disable dma clock,
the system has to enable the clock chain and it's parents ...
But with this patch, we only need to enable/disable dma clock one time,
just at we select the nand chip.
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