More Info: This seems to be related to cpm_uart_stop_tx() There seems to be an excessive amount of stops and starts going on In the following, I print an \ for each time stop_tx is called, and a / for start_tx
--------- EXT3-fs: mounted filesystem with ordered data mode. VFS: Mounted root (ext3 filesystem). Freeing unused kernel memory: 288k init \/I\/T\/?\/vers\/i\/on 2\/.\/85 b\/o\/otin\/?/ \/Acti\/v\/atin\/g\/ all\/ \/swap\/ \/file\/s\//par\/t\/itio\/n\/s...\<6>Adding 1028152k swap on /dev/hda2. Priority:1 extents:1 / \/[ \/OK\/ ]\/ \/Moun\/t\/ing \/p\/roc \/f\/ile \/s\/yste\/m\/...\/ \/[ \/OK\/ ]\/ \/Moun\/t\/ing \/r\/oot \/f\/ile \/s\/yste\/m\/ in \/r\/ead-\/o\/nly \/m\/ode.\/.\/.\/ ---------- And so on. If I put in a udelay(10000) at the end of cpm_uart_stop_tx, all output prints OK, but slow. 2.6.7 and prior does not use the stop at all form what I can see. > -----Original Message----- > From: Rune Torgersen > Sent: Tuesday, February 01, 2005 08:42 > To: linuxppc-embedded at ozlabs.org > Subject: 8266 SMC uart corruption > > Hi > > Has anybordy else seen corruption of the output from SMC1 > when used as serial console? > This only occurs in in 2.6.8 and later (when the CPM serial > drivers got moved) > And it only occurs when init is writing to screen. 2.6.7 and > earlier works perfectly. > It happens at all baudrates tested (9600 and 115200) > > Anybody seen something similar and/or have a clue where to > start looking for this? > I have looked at the serial drivers, and cannot find any > differences large differences from whenthey still were in > arch/ppc/8260_io to the ones in drivers/serial/cpm_uart > > Capture: > > Freeing unused kernel memory: 288k i?t > I?T: version 2.85 boot?g > ... > I?T?Entering runlevel: 3 > > > These lines are the only ones that get corrupted. All other > output (kernel printouts, console and startup scripts) are normal.
