Messages in this thread | | | Subject | Re: omap uart + dma issues (Re: [PATCH] tty: serial: 8250_omap: do not defer termios changes) | From | Sekhar Nori <> | Date | Wed, 13 Apr 2016 16:41:23 +0530 |
| |
On Wednesday 13 April 2016 05:30 AM, Peter Hurley wrote:
>>> - generates spurious uart interrupt for every rx dma transaction >>> (ie., necessitates acking every UART interrupt, even UART_IIR_NO_INT) >>> _Even with this workaround_, it still generates spurious interrupt warning >>> which shuts off interrupts for several ms while logging the error >>> message to the console, virtually guaranteeing lost data. >> >> as I wrote in my other email I think RDI should be disabled with DMA > > > I'll test to see if disabling RDI eliminates the UART_IIR_NO_INT spurious > interrupts. > >> according the Intel manual and I *think* someone here reported that >> they see the same problem. > > Let's confirm with the Intel folks that this is true, which would argue > for using the omap-style rx dma flow.
Andy Shevchenko pointed this out here: https://lkml.org/lkml/2016/2/23/588
Regards, Sekhar
| |