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vt: remove bogus lock dropping 

For hysterical raisins the vt layer drops and retakes locks in the write
method. This is a left over from the days when user/kernel data was passed
directly to the tty not pre-buffered.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Alan Cox 2008-10-13 10:41:16 +01:00 committed by Linus Torvalds
parent 15582d36a1
commit bf7a06bcce
1 changed files with 0 additions and 18 deletions
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18
drivers/char/vt.c
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@ -2136,27 +2136,9 @@ static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int co
release_console_sem();
return 0;
}
release_console_sem();
orig_buf = buf;
orig_count = count;
/* At this point 'buf' is guaranteed to be a kernel buffer
* and therefore no access to userspace (and therefore sleeping)
* will be needed. The con_buf_mtx serializes all tty based
* console rendering and vcs write/read operations. We hold
* the console spinlock during the entire write.
*/
acquire_console_sem();
vc = tty->driver_data;
if (vc == NULL) {
printk(KERN_ERR "vt: argh, driver_data _became_ NULL !\n");
release_console_sem();
goto out;
}
himask = vc->vc_hi_font_mask;
charmask = himask ? 0x1ff : 0xff;