From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeremy Kerr Date: Wed, 21 Mar 2018 10:52:37 +0800 Subject: [PATCH 1/5] serial: Introduce UPSTAT_SYNC_FIFO for synchronised FIFOs In-Reply-To: <20180321025241.19785-1-jk@ozlabs.org> References: <20180321025241.19785-1-jk@ozlabs.org> Message-ID: <20180321025241.19785-2-jk@ozlabs.org> List-Id: To: linux-aspeed@lists.ozlabs.org MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit This change adds a flag to indicate that a UART is has an external means of synchronising its FIFO, without needing CTSRTS or XON/XOFF. This allows us to use the throttle/unthrottle callbacks, without having to claim other methods of flow control. Signed-off-by: Jeremy Kerr --- drivers/tty/serial/serial_core.c | 4 ++-- include/linux/serial_core.h | 1 + 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index f534a40aebde..8f3dfc8b5307 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -678,7 +678,7 @@ static void uart_throttle(struct tty_struct *tty) if (C_CRTSCTS(tty)) mask |= UPSTAT_AUTORTS; - if (port->status & mask) { + if (port->status & (mask | UPSTAT_SYNC_FIFO)) { port->ops->throttle(port); mask &= ~port->status; } @@ -707,7 +707,7 @@ static void uart_unthrottle(struct tty_struct *tty) if (C_CRTSCTS(tty)) mask |= UPSTAT_AUTORTS; - if (port->status & mask) { + if (port->status & (mask | UPSTAT_SYNC_FIFO)) { port->ops->unthrottle(port); mask &= ~port->status; } diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h index 1775500294bb..bf600ae0290d 100644 --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -232,6 +232,7 @@ struct uart_port { #define UPSTAT_AUTORTS ((__force upstat_t) (1 << 2)) #define UPSTAT_AUTOCTS ((__force upstat_t) (1 << 3)) #define UPSTAT_AUTOXOFF ((__force upstat_t) (1 << 4)) +#define UPSTAT_SYNC_FIFO ((__force upstat_t) (1 << 5)) int hw_stopped; /* sw-assisted CTS flow state */ unsigned int mctrl; /* current modem ctrl settings */ -- 2.14.1