[RFC/PATCH 07/13] serial: omap: simplify IRQ handling
From: Felipe Balbi <hidden>
Date: 2012-08-21 09:20:28
Also in:
linux-omap, linux-serial, lkml
Subsystem:
the rest, tty layer and serial drivers · Maintainers:
Linus Torvalds, Greg Kroah-Hartman, Jiri Slaby
quite a few changes here, though they are pretty obvious. In summary we're making sure to detect which interrupt type we need to handle before calling the underlying interrupt handling procedure. Signed-off-by: Felipe Balbi <redacted> --- drivers/tty/serial/omap-serial.c | 47 ++++++++++++++++++++++++++++++---------- 1 file changed, 35 insertions(+), 12 deletions(-)
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 4d74a9b..1ca08b8 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c@@ -350,32 +350,55 @@ static inline irqreturn_t serial_omap_irq(int irq, void *dev_id) { struct uart_omap_port *up = dev_id; unsigned int iir, lsr; + unsigned int type; unsigned long flags; + spin_lock_irqsave(&up->port.lock, flags); pm_runtime_get_sync(up->dev); iir = serial_in(up, UART_IIR); - if (iir & UART_IIR_NO_INT) { - pm_runtime_mark_last_busy(up->dev); - pm_runtime_put_autosuspend(up->dev); - return IRQ_HANDLED; - } +again: + if (iir & UART_IIR_NO_INT) + goto out; - spin_lock_irqsave(&up->port.lock, flags); lsr = serial_in(up, UART_LSR); - if (iir & UART_IIR_RLSI) { + + /* extract IRQ type from IIR register */ + type = iir & 0x3e; + + switch (type) { + case UART_IIR_MSI: + check_modem_status(up); + break; + case UART_IIR_THRI: + if (lsr & UART_LSR_THRE) + transmit_chars(up); + break; + case UART_IIR_RDI: if (lsr & UART_LSR_DR) receive_chars(up, &lsr); + break; + case UART_IIR_RLSI: + if (lsr & UART_LSR_BRK_ERROR_BITS) + receive_chars(up, &lsr); + break; + case UART_IIR_RX_TIMEOUT: + receive_chars(up, &lsr); + break; + case UART_IIR_CTS_RTS_DSR: + iir = serial_in(up, UART_IIR); + goto again; + case UART_IIR_XOFF: + /* FALLTHROUGH */ + default: + break; } - check_modem_status(up); - if ((lsr & UART_LSR_THRE) && (iir & UART_IIR_THRI)) - transmit_chars(up); - +out: spin_unlock_irqrestore(&up->port.lock, flags); pm_runtime_mark_last_busy(up->dev); pm_runtime_put_autosuspend(up->dev); - up->port_activity = jiffies; + return IRQ_HANDLED; }
--
1.7.12.rc3