Messages in this thread | | | Subject | Re: [PATCH] tty: serial: 8250_omap: do not defer termios changes | From | Peter Hurley <> | Date | Mon, 11 Apr 2016 10:53:19 -0700 |
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On 04/11/2016 01:18 AM, John Ogness wrote: > On 2016-04-05, Peter Hurley <peter@hurleysoftware.com> 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.
http://www.spinics.net/lists/linux-serial/msg18503.html
So I'm wondering if we're carrying all this extra DMA complexity and workarounds for just am335x?
> Note: To achieve the stall, both the delayed_restore and the > rx_dma_broken features of the mainline 8250_omap driver needed to > be removed. > > John Ogness >
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