From mboxrd@z Thu Jan 1 00:00:00 1970 From: balbi@ti.com (Felipe Balbi) Date: Thu, 6 Sep 2012 15:45:23 +0300 Subject: [PATCH v4 04/21] serial: omap: simplify IRQ handling In-Reply-To: <1346935540-1792-1-git-send-email-balbi@ti.com> References: <20120906122948.GC29202@arwen.pp.htv.fi> <1346935540-1792-1-git-send-email-balbi@ti.com> Message-ID: <1346935540-1792-5-git-send-email-balbi@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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. Tested-by: Shubhrajyoti D Acked-by: Santosh Shilimkar Signed-off-by: Felipe Balbi --- drivers/tty/serial/omap-serial.c | 51 ++++++++++++++++++++++++++++++---------- 1 file changed, 38 insertions(+), 13 deletions(-) diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c index dd3971f..d5a08cb 100644 --- a/drivers/tty/serial/omap-serial.c +++ b/drivers/tty/serial/omap-serial.c @@ -351,33 +351,58 @@ 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_NONE; + 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_NONE; - } +again: + if (iir & UART_IIR_NO_INT) + goto out; - spin_lock_irqsave(&up->port.lock, flags); + ret = IRQ_HANDLED; 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