On Tue, Oct 15, 2013 at 08:55:20AM -0700, Dan Williams wrote: > On Tue, Oct 15, 2013 at 11:31 AM, Youquan Song > <youquan.s...@linux.intel.com> wrote: > > On Sun, Oct 13, 2013 at 08:56:33PM +0530, Vinod Koul wrote: > >> On Fri, Oct 11, 2013 at 06:33:43AM -0700, Greg KH wrote: > >> > On Fri, Oct 11, 2013 at 05:42:17PM -0400, Youquan Song wrote: > > The issue is that when I using UART to transfer data between to COMs > > which using Designware DMA controller channel. But I check the specific > > DMA channel by "cat /sys/class/dma/dma0chan3/bytes_transferred", but it > > should all "0". I have transferred data by UART port, why its DMA > > channel report "0" bytes transferred? So I guess that it is possible > > the DMA device driver issue or the data does not use the Designware DMA > > channel > > fro transferred. After check the code, I notice only when the DMA > > channel used by network device driver and it will record how much data has > > been > > tranferred, why other device driver will not calculate it. Since DMA > > channel is used by other device driver, why only network is specific? > > since it is > > common interface, the current /sys/class/dma/dma0chan*/bytes_transferred has > > much possibility to mislead the user. > > Yes, and for that reason I think we should delete " > /sys/class/dma/dma0chan*/bytes_transferred" it really serves no useful > purpose besides "is my dma channel working" which can be determined by > other means. Well am going to take it a bit further and ask you why do we need the /sys/class/dma? I have never used it for slave work.
Does it get used anywhere in async_tx? -- ~Vinod -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
