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. -- Dan -- 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/
