On 04/11/2016 07:53 PM, Peter Hurley wrote: > On 04/11/2016 01:18 AM, John Ogness wrote: >> On 2016-04-05, Peter Hurley <peter@xxxxxxxxxxxxxxxxxx> wrote: >>> On 03/31/2016 01:41 AM, John Ogness wrote: >>>> It has been observed that the TX-DMA can stall >>> >>> Does this happen on any other OMAP part besides am335x? >>> I looked back over the LKML history of this and didn't see >>> any other design implicated in this problem. >> >> I just ran the tests again using 4.6-rc2. I am able to reproduce the >> dma-tx stall with am335x/edma and dra7/sdma. > > I thought we already established sdma was not to be used since > the hardware does not actually support pausing without data loss. This workaround was not invented for sdma but for edma (with am335x). > http://www.spinics.net/lists/linux-serial/msg18503.html This could be fixed. See http://www.spinics.net/lists/linux-serial/msg18517.html http://www.spinics.net/lists/linux-serial/msg18531.html rmk was fine with it from what I read. So what is missing is just refurbish the patch (update the comment according to rmk replay) and then we could re-enable DMA again. > So I'm wondering if we're carrying all this extra DMA complexity > and workarounds for just am335x? > Sebastian -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
