Messages in this thread | | | Date | Mon, 18 Feb 2002 17:16:50 -0500 (EST) | From | Craig <> | Subject | Serial Console changes in linux 2.4.15?? |
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Hi all,
I have run into a problem with using my serial port as a console in linux 2.4.17, and tracked down the change. Just wondering if anyone could shed some light on the situation. Here's the scoop:
In Linux 2.4.10 -> 2.4.14 (and probably earlier than 2.4.10, but i didn't check) my serial console port works just fine. I then started using 2.4.17 and the serial port would continue to spit out output, but would not accept any input. I turned on the debugging statements and traced the problem down to the following piece of code from "drivers/char/serial.c".
function -> "change_speed"
#if 0 /* breaks serial console during boot stage */ /* * !!! ignore all characters if CREAD is not set */ if ((cflag & CREAD) == 0) info->ignore_status_mask |= UART_LSR_DR; #endif
The "#if 0" statements exist in 2.4.10 -> 2.4.14. In Linux 2.4.15, the "#if 0" statements were removed, so now that code is hit, and all the input characters are now ignored. It is still missing in 2.4.16 & 2.4.17. If i manually put the lines back (the "#if 0" and "#endif"), then my serial console works just fine.
Did someone submit serial.c with the "#if 0" lines removed by accident? I did look at the 2.4.15 changelog and could not see any changes regarding this.
My other question is: Why does this break the serial console? Someone must have know it has that affect in 2.4 because of the comment that is in the "#if 0" line. Any idea what is causing 'cflag' to be improperly set in the serial driver? I'd much prefer to fix the root problem, as opposed to putting in the "#if 0" work-around.
Any ideas or pointers would be most appreciated. Thanks.
-- Craig. +------------------------------------------------------+ http://www.wombat.ca Why? Why not. http://www.washington.edu/pine/ Pine @ the U of Wash. +-------------=*sent via Pine4.42*=--------------------+
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