On 12/16/2018 11:28 PM, Paul Burton wrote: > Hi Marek, > > On Sun, Dec 16, 2018 at 11:01:18PM +0100, Marek Vasut wrote: >>>>> I did suggest an alternative approach which would rename >>>>> serial8250_clear_fifos() and split it into 2 variants - one that >>>>> disables FIFOs & one that does not, then use the latter in >>>>> __do_stop_tx_rs485(): >>>>> >>>>> https://lore.kernel.org/lkml/20181213014805.77u5dzydo23cm6fq@pburton-laptop/ >>>>> >>>>> However I have no access to the OMAP3 hardware that Marek's patch was >>>>> attempting to fix & have heard nothing back with regards to him testing >>>>> that approach, so here's a simple revert that fixes the Ingenic JZ4780. >>>>> >>>>> I've marked for stable back to v4.10 presuming that this is how far the >>>>> broken patch may be backported, given that this is where commit >>>>> 2bed8a8e7072 ("Clearing FIFOs in RS485 emulation mode causes subsequent >>>>> transmits to break") that it tried to fix was introduced. >>>> >>>> OK, I tested this on AM335x / OMAP3 and the system is again broken, so >>>> that's a NAK. >>> >>> To be clear - what did you test? This revert or the patch linked to >>> above? >>> >>> This revert would of course reintroduce your RS485 issue because it just >>> undoes your change. >> >> The revert. Which of the two patches do you need me to test. > > The one in the email I sent on Thursday 13th at 01:48:06 UTC, linked to > at lore.kernel.org in the quote right above: > > https://lore.kernel.org/lkml/20181213014805.77u5dzydo23cm6fq@pburton-laptop/ > > You replied with comments on the patch, you just never tested it or > never told me if you did. The lack of response means I don't know > whether that potential patch even still works for your system, hence the > revert. I shared the entire testcase, which now fails on AM335x due to this revert. Is there any progress on a proper fix from your side which does not break the AM335x ? -- Best regards, Marek Vasut
