Hi Robert, On 09/08/2019 10:17, Sudip Mukherjee wrote: > > > On 08/08/2019 17:41, Andy Shevchenko wrote: >> On Wed, Aug 07, 2019 at 02:41:47PM -0400, Robert Middleton wrote: >>> On Wed, Aug 7, 2019 at 11:04 AM Andy Shevchenko >>> <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote: >>>> >>>> On Wed, Aug 07, 2019 at 09:48:03AM -0400, Robert Middleton wrote: >>>>>> I'll try to get some firm results in the morning; otherwise I won't be >>>>>> able to check until early next week as I will be away from the >>>>>> hardware. >>>>> >>>>> After doing more testing, I think that I finally have something that >>>>> is working fully at all baud rates. I've tested this at >>>>> 115200,9600,and 4800, testing via: echo "the quick brown fox jumps >>>>> over the lazy dog" > /dev/ttySx >>>>> >>>>> Removing the check to uart_circ_empty in the while loop makes it more >>>>> reliable, however it will occasionally fail and only transmit the >>>>> first part of the message(at 4800, it will transmit only "t", at >>>>> 115200 it will transmit "the quick bro"). >>>> >>>> I'm not sure about the loop for uart_circ_empty(). Can you try 2-3 kB of text >>>> at lower baud rate, let's say 2400 or so? >>> > <snip> >> >>> At this point, this leads me to believe that there is actually a more >>> fundamental problem with the 8250 driver and flushing data. I was >>> focusing more on the exar, since that is the only hardware that I have >>> available that uses the 8250 driver. >> >> Hmm... It's weird that no-one else had noticed so far an issue. > > Thats odd. I never saw this problem. Or even the people from "RTD > Embedded Technologies" who tested my first driver submission also did > not see any such problem. > I am on holiday now and don't have access to the hardware. I can check > it on my hardware after 2 weeks. Sorry for the delay. I managed to test it today. My test file contained 70 lines of "The quick brown fox jumps over the lazy dog". I used upto 1200 Baudrate to send the text from the desktop using the Exar serial I have and I did not notice any message loss on the receiving laptop. Please let me know if you want me to test further. -- Regards Sudip
