Merge "serial: msm_geni_serial: Remove interrupt storm" (fbe22f0f) · Commits · e / devices / android_kernel_fairphone_FP3

drivers/tty/serial/msm_geni_serial.c

+25 −1

Original line number	Diff line number	Diff line
		@@ -1302,6 +1302,7 @@ static int msm_geni_serial_handle_tx(struct uart_port *uport, bool done,
		unsigned int fifo_width_bytes =
		(uart_console(uport) ? 1 : (msm_port->tx_fifo_width >> 3));
		int temp_tail = 0;
		int irq_en;

		tx_fifo_status = geni_read_reg_nolog(uport->membase,
		SE_GENI_TX_FIFO_STATUS);
		@@ -1332,6 +1333,12 @@ static int msm_geni_serial_handle_tx(struct uart_port *uport, bool done,
		if (!msm_port->cur_tx_remaining) {
		msm_geni_serial_setup_tx(uport, pending);
		msm_port->cur_tx_remaining = pending;

		/* Re-Enable WATERMARK interrupt while starting new transfer */
		irq_en = geni_read_reg_nolog(uport->membase, SE_GENI_M_IRQ_EN);
		if (!(irq_en & M_TX_FIFO_WATERMARK_EN))
		geni_write_reg_nolog(irq_en \| M_TX_FIFO_WATERMARK_EN,
		uport->membase, SE_GENI_M_IRQ_EN);
		}

		bytes_remaining = xmit_size;
		@@ -1359,7 +1366,24 @@ static int msm_geni_serial_handle_tx(struct uart_port *uport, bool done,
		wmb();
		}
		xmit->tail = temp_tail;

		/*
		* The tx fifo watermark is level triggered and latched. Though we had
		* cleared it in qcom_geni_serial_isr it will have already reasserted
		* so we must clear it again here after our writes.
		*/
		geni_write_reg_nolog(M_TX_FIFO_WATERMARK_EN, uport->membase,
		SE_GENI_M_IRQ_CLEAR);

		exit_handle_tx:
		if (!msm_port->cur_tx_remaining) {
		/* Clear WATERMARK interrupt for each transfer completion */
		irq_en = geni_read_reg_nolog(uport->membase, SE_GENI_M_IRQ_EN);
		if (irq_en & M_TX_FIFO_WATERMARK_EN)
		geni_write_reg_nolog(irq_en & ~M_TX_FIFO_WATERMARK_EN,
		uport->membase, SE_GENI_M_IRQ_EN);
		}

		if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
		uart_write_wakeup(uport);
		return ret;