Merge "serial: msm_geni_serial: Fix the race between termios and ISR" (00e5bd25) · Commits · e / devices / android_kernel_fairphone_FP3

drivers/tty/serial/msm_geni_serial.c

+14 −6

Original line number	Diff line number	Diff line
		@@ -617,7 +617,6 @@ static void msm_geni_serial_abort_rx(struct uart_port *uport)
		static void msm_geni_serial_complete_rx_eot(struct uart_port *uport)
		{
		int poll_done = 0, tries = 0;
		u32 geni_status = 0;
		struct msm_geni_serial_port *port = GET_DEV_PORT(uport);

		do {
		@@ -626,11 +625,11 @@ static void msm_geni_serial_complete_rx_eot(struct uart_port *uport)
		tries++;
		} while (!poll_done && tries < 5);

		geni_status = geni_read_reg_nolog(uport->membase, SE_GENI_STATUS);

		if (!poll_done)
		IPC_LOG_MSG(port->ipc_log_misc, "%s: RX_EOT, GENI:0x%x\n",
		__func__, geni_status);
		IPC_LOG_MSG(port->ipc_log_misc,
		"%s: RX_EOT, GENI:0x%x, DMA_DEBUG:0x%x\n", __func__,
		geni_read_reg_nolog(uport->membase, SE_GENI_STATUS),
		geni_read_reg_nolog(uport->membase, SE_DMA_DEBUG_REG0));
		else
		geni_write_reg_nolog(RX_EOT, uport->membase, SE_DMA_RX_IRQ_CLR);
		}
		@@ -1131,7 +1130,9 @@ static void stop_rx_sequencer(struct uart_port *uport)
		* cancel control bit.
		*/
		mb();
		if (!uart_console(uport))
		msm_geni_serial_complete_rx_eot(uport);

		done = msm_geni_serial_poll_bit(uport, SE_GENI_S_CMD_CTRL_REG,
		S_GENI_CMD_CANCEL, false);
		if (done) {
		@@ -1856,6 +1857,7 @@ static void msm_geni_serial_set_termios(struct uart_port *uport,
		unsigned long ser_clk_cfg = 0;
		struct msm_geni_serial_port *port = GET_DEV_PORT(uport);
		unsigned long clk_rate;
		unsigned long flags;

		if (!uart_console(uport)) {
		int ret = msm_geni_serial_power_on(uport);
		@@ -1867,7 +1869,13 @@ static void msm_geni_serial_set_termios(struct uart_port *uport,
		return;
		}
		}
		/* Take a spinlock else stop_rx causes a race with an ISR due to Cancel
		* and FSM_RESET. This also has a potential race with the dma_map/unmap
		* operations of ISR.
		*/
		spin_lock_irqsave(&uport->lock, flags);
		msm_geni_serial_stop_rx(uport);
		spin_unlock_irqrestore(&uport->lock, flags);
		/* baud rate */
		baud = uart_get_baud_rate(uport, termios, old, 300, 4000000);
		port->cur_baud = baud;