[PATCH] serial: qcom-geni: Clear pending IRQs while suspended

[Praveen Talari]

When uart_suspend_port() marks a port suspended, an interrupt may still
be pending before TX and RX are stopped. Returning IRQ_NONE before taking
the port lock leaves those interrupt status bits uncleared and can cause
the interrupt to be retriggered.

Take the UART port lock and clear the relevant interrupt status first,
then skip interrupt processing while the port is suspended.

Signed-off-by: Praveen Talari <praveen.talari@xxxxxxxxxxxxxxxx>
---
 drivers/tty/serial/qcom_geni_serial.c | 28 +++++++++++++---------------
 1 file changed, 13 insertions(+), 15 deletions(-)

diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index bfdc155c128d..d8323d6b5286 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -1210,16 +1210,26 @@ static irqreturn_t qcom_geni_serial_isr(int isr, void *dev)
 	struct tty_port *tport = &uport->state->port;
 	struct qcom_geni_serial_port *port = to_dev_port(uport);
 
-	if (uport->suspended)
-		return IRQ_NONE;
-
 	uart_port_lock(uport);
 
+	m_irq_status = readl(uport->membase + SE_GENI_M_IRQ_STATUS);
 	s_irq_status = readl(uport->membase + SE_GENI_S_IRQ_STATUS);
+	dma_tx_status = readl(uport->membase + SE_DMA_TX_IRQ_STAT);
 	dma_rx_status = readl(uport->membase + SE_DMA_RX_IRQ_STAT);
+	geni_status = readl(uport->membase + SE_GENI_STATUS);
+	dma = readl(uport->membase + SE_GENI_DMA_MODE_EN);
+	m_irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
+	writel(m_irq_status, uport->membase + SE_GENI_M_IRQ_CLEAR);
 	writel(s_irq_status, uport->membase + SE_GENI_S_IRQ_CLEAR);
+	writel(dma_tx_status, uport->membase + SE_DMA_TX_IRQ_CLR);
 	writel(dma_rx_status, uport->membase + SE_DMA_RX_IRQ_CLR);
 
+	trace_geni_serial_irq(uport->dev, m_irq_status, s_irq_status,
+			      dma_tx_status, dma_rx_status);
+
+	if (uport->suspended)
+		goto out_unlock;
+
 	if (s_irq_status & S_RX_FIFO_WR_ERR_EN) {
 		uport->icount.overrun++;
 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
@@ -1234,18 +1244,6 @@ static irqreturn_t qcom_geni_serial_isr(int isr, void *dev)
 		port->brk = true;
 	}
 
-	m_irq_status = readl(uport->membase + SE_GENI_M_IRQ_STATUS);
-	dma_tx_status = readl(uport->membase + SE_DMA_TX_IRQ_STAT);
-	geni_status = readl(uport->membase + SE_GENI_STATUS);
-	dma = readl(uport->membase + SE_GENI_DMA_MODE_EN);
-	m_irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
-
-	trace_geni_serial_irq(uport->dev, m_irq_status, s_irq_status,
-			      dma_tx_status, dma_rx_status);
-
-	writel(m_irq_status, uport->membase + SE_GENI_M_IRQ_CLEAR);
-	writel(dma_tx_status, uport->membase + SE_DMA_TX_IRQ_CLR);
-
 	if (WARN_ON(m_irq_status & M_ILLEGAL_CMD_EN))
 		goto handle_rx;
 

---
base-commit: 2efb7a11f1aa4d2dc285fe2680cca22cb9f72f64
change-id: 20261019-ack-interrupts-on-suspended-port-0c1da05a8407

Best regards,
--  
Praveen Talari <praveen.talari@xxxxxxxxxxxxxxxx>