On (08/12/13 08:55), Peter Hurley wrote: > >>> [..] > >>> drivers/tty/n_tty.c | 25 +++++++++++-------------- > >>> 1 file changed, 11 insertions(+), 14 deletions(-) > >>> > > > >I hate to do this, but isn't it actually my patch posted here > >https://lkml.org/lkml/2013/8/1/510 > > > >which was tagged as `wrong'? > > Sergey, > > My apologies; I was mistaken regarding this problem being a lockdep > regression (although it's still a false positive from lockdep). Once > I had worked around some issues with the nouveau driver, I was able to > reproduce the lockdep report on 3.10. > no problem. > I included Artem's lockdep report in the changelog because I received > that first, on 30 July. > > My patch below is not the same as your patch of 1 Aug. This patch > preserves the protected access of termios.c_cc[VMIN] and termios.c_cc[VTIME] > (via the MIN_CHAR() and TIME_CHAR() macros). fair enough. v3 was protecting VMIN/VTIME (my bad, I noticed this a bit later), but I didn't submit it since v2 did not get positive response. > If you'd prefer, I could add to changelog: > > Patch based on original posted here https://lkml.org/lkml/2013/8/1/510 > by Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx> if you don't mind, that would be great. thanks a lot, -ss > Regards, > Peter Hurley > > > >>>diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c > >>>index dd8ae0c..c9a9ddd 100644 > >>>--- a/drivers/tty/n_tty.c > >>>+++ b/drivers/tty/n_tty.c > >>>@@ -2122,6 +2122,17 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, > >>> if (c < 0) > >>> return c; > >>> > >>>+ /* > >>>+ * Internal serialization of reads. > >>>+ */ > >>>+ if (file->f_flags & O_NONBLOCK) { > >>>+ if (!mutex_trylock(&ldata->atomic_read_lock)) > >>>+ return -EAGAIN; > >>>+ } else { > >>>+ if (mutex_lock_interruptible(&ldata->atomic_read_lock)) > >>>+ return -ERESTARTSYS; > >>>+ } > >>>+ > >>> down_read(&tty->termios_rwsem); > >>> > >>> minimum = time = 0; > >>>@@ -2141,20 +2152,6 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, > >>> } > >>> } > >>> > >>>- /* > >>>- * Internal serialization of reads. > >>>- */ > >>>- if (file->f_flags & O_NONBLOCK) { > >>>- if (!mutex_trylock(&ldata->atomic_read_lock)) { > >>>- up_read(&tty->termios_rwsem); > >>>- return -EAGAIN; > >>>- } > >>>- } else { > >>>- if (mutex_lock_interruptible(&ldata->atomic_read_lock)) { > >>>- up_read(&tty->termios_rwsem); > >>>- return -ERESTARTSYS; > >>>- } > >>>- } > >>> packet = tty->packet; > >>> > >>> add_wait_queue(&tty->read_wait, &wait); > >>>-- > >>>1.8.1.2 > >>> > >> > >>-- > >>Regards, > >> Artem > >> > -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
