On 08/15/2014 04:28 PM, Tony Lindgren wrote: > * Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> [140815 12:16]: >> On 08/15/2014 08:17 PM, Lennart Sorensen wrote: >> >>> Are you saying that with the new driver you have to respond to the RX >>> irq faster than before to avoid overflows? It is not quite clear. >> >> Yes. The irq fires 46 bytes giving you 16 bytes buffer before overflow >> vs 63 bytes buffer the old one had. >> >>> I do think 40000 interrupts to handle 40000 bytes of date does seem a >>> tad inefficient, so dropping to 854 looks a lot nicer. Was the omap >>> driver not using the fifo trigger levels at all? >> >> It configured the trigger levels to 1 for RX and 16 for TX. > > Hmm that weird RX trigger level is a workaround for lost characters. > > See commit 0ba5f66836 (tty: serial: OMAP: use a 1-byte RX FIFO > threshold in PIO mode :) That commit looks like it should have been specific to the silicon exhibiting the rx timeout bug. Regards, Peter Hurley -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
