---------- Forwarded message ----------
From: Devvrat Tripathi <tripathidevvrat@xxxxxxxxx>
Date: Jun 21, 2007 3:13 PM
Subject: Re: dma operations
To: kanishk rastogi <kanishk_rastogi85@xxxxxxxxx>
On 6/20/07,
kanishk rastogi <kanishk_rastogi85@xxxxxxxxx> wrote:
when you say interrupt then though it maybe the sureshot way to tell that the transfer is done, it becomes device specific too. I was interested in the generic dma support provided by the kernel. Again does a call to dma_unmap_* always mean a dma transfer is complete. This was for the streaming mappings. Could someone also explain the coherent mapping. How exactly does the device know in which direction the dma transfer is supposed to take place in that since there is no argument specifying the direction. Also how do you actually start and stop the data transfer in such mapping. I am sorry but i couldnt get the thing given in LDD3 properly
----- Original Message ----
From: Devvrat Tripathi <tripathidevvrat@xxxxxxxxx>
To: kernelnewbies@xxxxxxxxxxxx
Sent: Wednesday, June 20, 2007 7:12:33 PM
Subject: dma operations
How does the kernel get to know whenever a dma transfer is completed. Does a call to dma_unmap_* always mean that a dma transfer to the said device has been completed. If not then what method is called to indicate a finished dma transfer.
regards
devvrat
its some intrrupt......
code i dont know......
CMIIW
regards
kanishk
regards
devvrat
