[PATCH v4 1/2] tty: serial: qcom_geni_serial: IRQ cleanup

[Akash Asthana <akashast@xxxxxxxxxxxxxx>]

Move ISR registration from startup to probe function to avoid registering
it everytime when the port open is called for driver.

Signed-off-by: Akash Asthana <akashast@xxxxxxxxxxxxxx>
---
Changes in v4:
 - As per Stephen's comment, move ISR registration(later in probe) after
   registering uart port with serial core.
 - As per Greg's comment, corrected returning of PTR value from integer type
   function(probe).

Changes in v3:
 - As per Stephen's comment, using devm_kasprintf instead of scnprintf API.

 drivers/tty/serial/qcom_geni_serial.c | 38 ++++++++++++++++++++++++-----------
 1 file changed, 26 insertions(+), 12 deletions(-)

diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index 14c6306..634054a 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -9,6 +9,7 @@
 #include <linux/console.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
+#include <linux/irq.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
@@ -101,7 +102,7 @@
 struct qcom_geni_serial_port {
 	struct uart_port uport;
 	struct geni_se se;
-	char name[20];
+	const char *name;
 	u32 tx_fifo_depth;
 	u32 tx_fifo_width;
 	u32 rx_fifo_depth;
@@ -830,7 +831,7 @@ static void qcom_geni_serial_shutdown(struct uart_port *uport)
 	if (uart_console(uport))
 		console_stop(uport->cons);
 
-	free_irq(uport->irq, uport);
+	disable_irq(uport->irq);
 	spin_lock_irqsave(&uport->lock, flags);
 	qcom_geni_serial_stop_tx(uport);
 	qcom_geni_serial_stop_rx(uport);
@@ -890,21 +891,14 @@ static int qcom_geni_serial_startup(struct uart_port *uport)
 	int ret;
 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
 
-	scnprintf(port->name, sizeof(port->name),
-		  "qcom_serial_%s%d",
-		(uart_console(uport) ? "console" : "uart"), uport->line);
-
 	if (!port->setup) {
 		ret = qcom_geni_serial_port_setup(uport);
 		if (ret)
 			return ret;
 	}
+	enable_irq(uport->irq);
 
-	ret = request_irq(uport->irq, qcom_geni_serial_isr, IRQF_TRIGGER_HIGH,
-							port->name, uport);
-	if (ret)
-		dev_err(uport->dev, "Failed to get IRQ ret %d\n", ret);
-	return ret;
+	return 0;
 }
 
 static unsigned long get_clk_cfg(unsigned long clk_freq)
@@ -1297,6 +1291,12 @@ static int qcom_geni_serial_probe(struct platform_device *pdev)
 	port->rx_fifo_depth = DEF_FIFO_DEPTH_WORDS;
 	port->tx_fifo_width = DEF_FIFO_WIDTH_BITS;
 
+	port->name = devm_kasprintf(uport->dev, GFP_KERNEL,
+			"qcom_geni_serial_%s%d",
+			uart_console(uport) ? "console" : "uart", uport->line);
+	if (!port->name)
+		return -ENOMEM;
+
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0)
 		return irq;
@@ -1307,7 +1307,21 @@ static int qcom_geni_serial_probe(struct platform_device *pdev)
 	port->handle_rx = console ? handle_rx_console : handle_rx_uart;
 	if (!console)
 		device_create_file(uport->dev, &dev_attr_loopback);
-	return uart_add_one_port(drv, uport);
+
+	ret = uart_add_one_port(drv, uport);
+	if (ret)
+		return ret;
+
+	irq_set_status_flags(uport->irq, IRQ_NOAUTOEN);
+	ret = devm_request_irq(uport->dev, uport->irq, qcom_geni_serial_isr,
+			IRQF_TRIGGER_HIGH, port->name, uport);
+	if (ret) {
+		dev_err(uport->dev, "Failed to get IRQ ret %d\n", ret);
+		uart_remove_one_port(drv, uport);
+		return ret;
+	}
+
+	return ret;
 }
 
 static int qcom_geni_serial_remove(struct platform_device *pdev)
-- 
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