diff options
Diffstat (limited to 'Documentation/serial/driver')
| -rw-r--r-- | Documentation/serial/driver | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/Documentation/serial/driver b/Documentation/serial/driver index 3bba1aeb799c..c415b0ef4493 100644 --- a/Documentation/serial/driver +++ b/Documentation/serial/driver @@ -59,7 +59,9 @@ The core driver uses the info->tmpbuf_sem lock to prevent multi-threaded access to the info->tmpbuf bouncebuffer used for port writes. The port_sem semaphore is used to protect against ports being added/ -removed or reconfigured at inappropriate times. +removed or reconfigured at inappropriate times. Since v2.6.27, this +semaphore has been the 'mutex' member of the tty_port struct, and +commonly referred to as the port mutex (or port->mutex). uart_ops @@ -140,6 +142,8 @@ hardware. will append the character to the circular buffer and then call start_tx() / stop_tx() to flush the data out. + Do not transmit if ch == '\0' (__DISABLED_CHAR). + Locking: none. Interrupts: caller dependent. @@ -246,7 +250,7 @@ hardware. Other flags may be used (eg, xon/xoff characters) if your hardware supports hardware "soft" flow control. - Locking: none. + Locking: caller holds port->mutex Interrupts: caller dependent. This call must not sleep |