Hi all, I'm seeing a bug in an internal tree, based on 32-rc4, where characters that are given to the tty code seem to disappear. It sounds different, but perhaps somehow related to the problems in the "keyboard under X with 2.6.31" thread. I'm using hvc_console.c, and I see all my input read into there. Adding debug in tty_read() though, I see characters go missing. It's only 50 or so characters out of 4K or more. The bug is 100% reproducible, but only on an internal simulator (sorry). I'm running one cpu and one thread, with no preempt. I'm using 80f5069 or thereabouts, plus some powerpc patches. We also see the bug in 31, but not in 27. I've tried two of Linus' patches from the X keyboard thread, the one that changes flush_to_ldisc() and the one that adds locked_tty_buffer_request_room() - neither seems to help. I've also changed hvc_console.c to use tty_insert_flip_string(tty, c, 1) (which is locked after Linus' patch) instead of tty_insert_flip_char() - also didn't help. Some example debug output: 137352697: (137187792): hvc_fss_read_console: '.out 137353604: (137188699): cat strace' 137361976: (137197049): hvc_fss_read_console: '.out | callthru ' 137370882: (137205933): hvc_fss_read_console: 'sink /home/micha' 137379788: (137214817): hvc_fss_read_console: 'el/kbt/strace.ou' 137388696: (137223703): hvc_fss_read_console: 't 137389606: (137224613): callthru eval' 2396468919: (2340876339): (none) / # tty_read: read 1 chars 'c' 2396579463: (2340986479): ctty_read: read 1 chars 'a' 2396690167: (2341096780): atty_read: read 1 chars 't' 2396800851: (2341207061): ttty_read: read 1 chars ' ' 2396911580: (2341317387): tty_read: read 1 chars 's' 2397022603: (2341428007): stty_read: read 1 chars 't' 2397133524: (2341538525): ttty_read: read 1 chars 'r' 2397244739: (2341649337): rtty_read: read 1 chars 'a' 2397355852: (2341760047): atty_read: read 1 chars 'c' 2397467259: (2341871051): ctty_read: read 1 chars 'e' 2397578564: (2341981953): etty_read: read 1 chars '.' 2397690618: (2342093604): .tty_read: read 1 chars, newline 2397800089: (2342202671): 2399849231: (2344246188): cat: strace.: No such file or directory So we seem to have lost everything after the dot in the second ".out" until the end of the line. It's entirely possible this is a bug in hvc_console.c, or our arch patches, or the simulator .. or the tty code :) Anyway, if anyone has ideas or patches I'm all ears. cheers
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