From 5181fb3d51d2d886ec9b2fed13a9ad9d5d67ec1f Mon Sep 17 00:00:00 2001 From: Tomoya MORINAGA Date: Mon, 26 Mar 2012 14:43:03 +0900 Subject: [PATCH] pch_uart: Support modem status interrupt Signed-off-by: Tomoya MORINAGA Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/pch_uart.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c index d035f8ff913d..d11096c8ca81 100644 --- a/drivers/tty/serial/pch_uart.c +++ b/drivers/tty/serial/pch_uart.c @@ -1043,10 +1043,15 @@ static irqreturn_t pch_uart_interrupt(int irq, void *dev_id) int ret = 0; unsigned char iid; unsigned long flags; + int next = 1; + u8 msr; spin_lock_irqsave(&priv->port.lock, flags); handled = 0; - while ((iid = pch_uart_hal_get_iid(priv)) > 1) { + while (next) { + iid = pch_uart_hal_get_iid(priv); + if (iid & PCH_UART_IIR_IP) /* No Interrupt */ + break; switch (iid) { case PCH_UART_IID_RLS: /* Receiver Line Status */ lsr = pch_uart_hal_get_line_status(priv); @@ -1080,12 +1085,18 @@ static irqreturn_t pch_uart_interrupt(int irq, void *dev_id) ret = handle_tx(priv); break; case PCH_UART_IID_MS: /* Modem Status */ - ret = PCH_UART_HANDLED_MS_INT; + msr = pch_uart_hal_get_modem(priv); + next = 0; /* MS ir prioirty is the lowest. So, MS ir + means final interrupt */ + if ((msr & UART_MSR_ANY_DELTA) == 0) + break; + ret |= PCH_UART_HANDLED_MS_INT; break; default: /* Never junp to this label */ dev_err(priv->port.dev, "%s:iid=%02x (%lu)\n", __func__, iid, jiffies); ret = -1; + next = 0; break; } handled |= (unsigned int)ret;