| From | Andi Kleen <> | Subject | [PATCH] [67/275] parisc : Remove broken line wrapping handling pdc_iodc_print() | Date | Wed, 30 Mar 2011 14:05:04 -0700 (PDT) |
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2.6.35-longterm review patch. If anyone has any objections, please let me know.
------------------ From: Guy Martin <gmsoft@tuxicoman.be>
commit fbea668498e93bb38ac9226c7af9120a25957375 upstream.
Remove the broken line wrapping handling in pdc_iodc_print(). It is broken in 3 ways : - It doesn't keep track of the current screen position, it just assumes that the new buffer will be printed at the begining of the screen. - It doesn't take in account that non printable characters won't increase the current position on the screen. - And last but not least, it triggers a kernel panic if a backspace is the first char in the provided buffer :
Backtrace: [<0000000040128ec4>] pdc_console_write+0x44/0x78 [<0000000040128f18>] pdc_console_tty_write+0x20/0x38 [<000000004032f1ac>] n_tty_write+0x2a4/0x550 [<000000004032b158>] tty_write+0x1e0/0x2d8 [<00000000401bb420>] vfs_write+0xb8/0x188 [<00000000401bb630>] sys_write+0x68/0xb8 [<0000000040104eb8>] syscall_exit+0x0/0x14
Most terminals handle the line wrapping just fine. I've confirmed that it works correctly on a C8000 with both vga and serial output.
Signed-off-by: Guy Martin <gmsoft@tuxicoman.be> Signed-off-by: James Bottomley <James.Bottomley@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
--- arch/parisc/kernel/firmware.c | 13 +------------ 1 file changed, 1 insertion(+), 12 deletions(-)
Index: linux-2.6.35.y/arch/parisc/kernel/firmware.c =================================================================== --- linux-2.6.35.y.orig/arch/parisc/kernel/firmware.c 2011-03-29 22:51:43.187618105 -0700 +++ linux-2.6.35.y/arch/parisc/kernel/firmware.c 2011-03-29 23:02:59.573311089 -0700 @@ -1126,15 +1126,13 @@ unsigned int i; unsigned long flags; - for (i = 0; i < count && i < 79;) { + for (i = 0; i < count;) { switch(str[i]) { case '\n': iodc_dbuf[i+0] = '\r'; iodc_dbuf[i+1] = '\n'; i += 2; goto print; - case '\b': /* BS */ - i--; /* overwrite last */ default: iodc_dbuf[i] = str[i]; i++; @@ -1142,15 +1140,6 @@ } } - /* if we're at the end of line, and not already inserting a newline, - * insert one anyway. iodc console doesn't claim to support >79 char - * lines. don't account for this in the return value. - */ - if (i == 79 && iodc_dbuf[i-1] != '\n') { - iodc_dbuf[i+0] = '\r'; - iodc_dbuf[i+1] = '\n'; - } - print: spin_lock_irqsave(&pdc_lock, flags); real32_call(PAGE0->mem_cons.iodc_io,
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