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Subject[PATCH v2 06/13] serial: omap: simplify IRQ handling
Date
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.

Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
---
drivers/tty/serial/omap-serial.c | 48 +++++++++++++++++++++++++++++++---------
1 file changed, 37 insertions(+), 11 deletions(-)
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 16808b6..2d3e64e 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -350,33 +350,59 @@ 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;
+ irqreturn_t ret = IRQ_HANDLED;

+ spin_lock_irqsave(&up->port.lock, flags);
pm_runtime_get_sync(up->dev);
iir = serial_in(up, UART_IIR);
+again:
if (iir & UART_IIR_NO_INT) {
- pm_runtime_mark_last_busy(up->dev);
- pm_runtime_put_autosuspend(up->dev);
- return IRQ_NONE;
+ ret = IRQ_NONE;
+ 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;
+
+ return ret;
}

static unsigned int serial_omap_tx_empty(struct uart_port *port)
--
1.7.12.rc3


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