On Tue, Apr 17, 2018 at 05:57:48PM -0700, Tony Lindgren wrote: > * Russell King - ARM Linux <linux@xxxxxxxxxxxxxxx> [180417 22:12]: > > On Tue, Apr 17, 2018 at 10:31:35AM -0700, Tony Lindgren wrote: > > > * Vignesh R <vigneshr@xxxxxx> [180417 09:21]: > > > > On Monday 16 April 2018 09:15 PM, Tony Lindgren wrote: > > > > > Also, I'm seeing an issue where the UARTs won't idle on init > > > > > with 8250_omap driver if connected to the wl12xx bluetooth port > > > > > unless I write some data to the port first. It does not seem > > > > > to be related to the rts/cts lines being wired as I've tested > > > > > muxing them out of the way. > > > > > > > > If this instance of UART is using DMA then it might be due an errata > > > > worked around in AM33/AM43/DRA7: > > > > https://patchwork.kernel.org/patch/6784331/ > > > > > > It sure sounds similar but UART_ERRATA_CLOCK_DISABLE does not > > > seem to help with the reset. Also disabling DMA does not seem > > > to help. So far the only way to clear it seems to be to write > > > a character (TX) on the device. Then things work just fine > > > even without UART_ERRATA_CLOCK_DISABLE set. I'll try to debug > > > this more at some point. > > > > Classic case of thread hijack. So, Tony's idle problem gets more > > attention on _my_ thread than _my_ issue about TX corruption, yea, > > that's fair... Come on guys, what about my problem, which is the > > subject of this thread? > > Just trying to brainstorm what all can go wrong still :) OK so > it's not DMA then. > > > I don't have CONFIG_SERIAL_8250_DMA set, so DMA can't be the issue. > > Is this happening also with v4.16 or with v4.17-rc1? 4.16 > So you just edit something in vi and and on exit it happens? > Not happening here for me.. Or run less, eg, dmesg | less or less /some/file. It doesn't happen with cat though. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 8.8Mbps down 630kbps up According to speedtest.net: 8.21Mbps down 510kbps up -- 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
