[PATCH] new tty buffering locking fix

Change locking in the new tty buffering facility from using tty->read_lock,
which is currently ignored by drivers and thus ineffective.  New locking
uses a new tty buffering specific lock enforced centrally in the tty
buffering code.

Two drivers (esp and cyclades) are updated to use the tty buffering
functions instead of accessing tty buffering internals directly.  This is
required for the new locking to work.

Minor checks for NULL buffers added to
tty_prepare_flip_string/tty_prepare_flip_string_flags

Signed-off-by: Paul Fulghum <paulkf@microgate.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/char/esp.c b/drivers/char/esp.c
index 3f3ac039f4d9..57539d8f9f7c 100644
--- a/drivers/char/esp.c
+++ b/drivers/char/esp.c
@@ -359,7 +359,7 @@ static inline void receive_chars_pio(struct esp_struct *info, int num_bytes)
                 }
         }
 
-        schedule_delayed_work(&tty->buf.work, 1);
+        tty_schedule_flip(tty);
 
         info->stat_flags &= ~ESP_STAT_RX_TIMEOUT;
         release_pio_buffer(pio_buf);
@@ -426,7 +426,7 @@ static inline void receive_chars_dma_done(struct esp_struct *info,
                         }
                         tty_insert_flip_char(tty, dma_buffer[num_bytes - 1], statflag);
                 }
-                schedule_delayed_work(&tty->buf.work, 1);
+                tty_schedule_flip(tty);
         }
 
         if (dma_bytes != num_bytes) {