Merge "tty: serial: msm_geni_serial: Resolve race btw stop rx and cancel rx" (d9d4c632) · Commits · e / devices / android_kernel_oneplus_sm7250

drivers/tty/serial/msm_geni_serial.c

+103 −58

Original line number	Diff line number	Diff line
		@@ -210,6 +210,7 @@ struct msm_geni_serial_port {
		bool s_cmd;
		struct completion m_cmd_timeout;
		struct completion s_cmd_timeout;
		spinlock_t rx_lock;
		};

		static const struct uart_ops msm_geni_serial_pops;
		@@ -236,6 +237,7 @@ static int msm_geni_serial_runtime_suspend(struct device *dev);
		static int msm_geni_serial_get_ver_info(struct uart_port *uport);
		static void msm_geni_serial_set_manual_flow(bool enable,
		struct msm_geni_serial_port *port);
		static bool handle_rx_dma_xfer(u32 s_irq_status, struct uart_port *uport);
		static int uart_line_id;

		#define GET_DEV_PORT(uport) \
		@@ -1438,6 +1440,7 @@ static int stop_rx_sequencer(struct uart_port *uport)
		unsigned long flags = 0;
		bool is_rx_active;
		unsigned int stale_delay;
		u32 dma_rx_status, s_irq_status;

		IPC_LOG_MSG(port->ipc_log_misc, "%s\n", __func__);

		@@ -1462,6 +1465,25 @@ static int stop_rx_sequencer(struct uart_port *uport)
		stale_delay = (STALE_COUNT * SEC_TO_USEC) / port->cur_baud;
		stale_delay = (2 * stale_delay) + SYSTEM_DELAY;
		udelay(stale_delay);

		dma_rx_status = geni_read_reg_nolog(uport->membase,
		SE_DMA_RX_IRQ_STAT);
		/* The transfer is completed at HW level and the completion
		* interrupt is delayed. So process the transfer completion
		* before issuing the cancel command to resolve the race
		* btw cancel RX and completion interrupt.
		*/
		if (dma_rx_status) {
		s_irq_status = geni_read_reg_nolog(uport->membase,
		SE_GENI_S_IRQ_STATUS);
		geni_write_reg_nolog(s_irq_status, uport->membase,
		SE_GENI_S_IRQ_CLEAR);
		geni_se_dump_dbg_regs(&port->serial_rsc,
		uport->membase, port->ipc_log_misc);
		IPC_LOG_MSG(port->ipc_log_misc, "%s: Interrupt delay\n",
		__func__);
		handle_rx_dma_xfer(s_irq_status, uport);
		}
		}

		IPC_LOG_MSG(port->ipc_log_misc, "%s: Start 0x%x\n",
		@@ -1863,6 +1885,77 @@ static int msm_geni_serial_handle_dma_tx(struct uart_port *uport)
		return 0;
		}

		static bool handle_rx_dma_xfer(u32 s_irq_status, struct uart_port *uport)
		{
		bool ret = false;
		bool drop_rx = false;
		struct msm_geni_serial_port *msm_port = GET_DEV_PORT(uport);
		u32 dma_rx_status;

		spin_lock(&msm_port->rx_lock);
		dma_rx_status = geni_read_reg_nolog(uport->membase,
		SE_DMA_RX_IRQ_STAT);

		if (dma_rx_status) {
		geni_write_reg_nolog(dma_rx_status, uport->membase,
		SE_DMA_RX_IRQ_CLR);

		if (dma_rx_status & RX_RESET_DONE) {
		IPC_LOG_MSG(msm_port->ipc_log_misc,
		"%s.Reset done. 0x%x.\n", __func__, dma_rx_status);
		ret = true;
		goto exit;
		}

		if (dma_rx_status & UART_DMA_RX_ERRS) {
		if (dma_rx_status & UART_DMA_RX_PARITY_ERR)
		uport->icount.parity++;
		IPC_LOG_MSG(msm_port->ipc_log_misc,
		"%s.Rx Errors. 0x%x parity:%d\n",
		__func__, dma_rx_status,
		uport->icount.parity);
		drop_rx = true;
		} else if (dma_rx_status & UART_DMA_RX_BREAK) {
		uport->icount.brk++;
		IPC_LOG_MSG(msm_port->ipc_log_misc,
		"%s.Rx Errors. 0x%x break:%d\n",
		__func__, dma_rx_status,
		uport->icount.brk);
		}

		if (dma_rx_status & RX_EOT \|\|
		dma_rx_status & RX_DMA_DONE) {
		msm_geni_serial_handle_dma_rx(uport,
		drop_rx);
		if (!(dma_rx_status & RX_GENI_CANCEL_IRQ)) {
		geni_se_rx_dma_start(uport->membase,
		DMA_RX_BUF_SIZE, &msm_port->rx_dma);
		} else {
		IPC_LOG_MSG(msm_port->ipc_log_misc,
		"%s. not mapping rx dma\n",
		__func__);
		}
		}
		if (dma_rx_status & RX_SBE) {
		IPC_LOG_MSG(msm_port->ipc_log_misc,
		"%s.Rx Errors. 0x%x\n",
		__func__, dma_rx_status);
		WARN_ON(1);
		}

		if (dma_rx_status & (RX_EOT \| RX_GENI_CANCEL_IRQ \| RX_DMA_DONE))
		ret = true;

		}

		if (s_irq_status & (S_CMD_CANCEL_EN \| S_CMD_ABORT_EN))
		ret = true;

		exit:
		spin_unlock(&msm_port->rx_lock);
		return ret;
		}

		static void msm_geni_serial_handle_isr(struct uart_port *uport,
		unsigned long *flags,
		bool is_irq_masked)
		@@ -1994,70 +2087,19 @@ static void msm_geni_serial_handle_isr(struct uart_port *uport,
		TX_GENI_CANCEL_IRQ))
		m_cmd_done = true;

		if (m_irq_status & (M_CMD_CANCEL_EN \| M_CMD_ABORT_EN))
		m_cmd_done = true;

		if ((dma_tx_status & TX_DMA_DONE) && !m_cmd_done)
		msm_geni_serial_handle_dma_tx(uport);
		}

		if (dma_rx_status) {
		geni_write_reg_nolog(dma_rx_status, uport->membase,
		SE_DMA_RX_IRQ_CLR);

		if (dma_rx_status & RX_RESET_DONE) {
		IPC_LOG_MSG(msm_port->ipc_log_misc,
		"%s.Reset done. 0x%x.\n",
		__func__, dma_rx_status);
		s_cmd_done = true;
		goto exit_geni_serial_isr;
		}

		if (dma_rx_status & UART_DMA_RX_ERRS) {
		if (dma_rx_status & UART_DMA_RX_PARITY_ERR)
		uport->icount.parity++;
		IPC_LOG_MSG(msm_port->ipc_log_misc,
		"%s.Rx Errors. 0x%x parity:%d\n",
		__func__, dma_rx_status,
		uport->icount.parity);
		drop_rx = true;
		} else if (dma_rx_status & UART_DMA_RX_BREAK) {
		uport->icount.brk++;
		IPC_LOG_MSG(msm_port->ipc_log_misc,
		"%s.Rx Errors. 0x%x break:%d\n",
		__func__, dma_rx_status,
		uport->icount.brk);
		}

		if (dma_rx_status & RX_EOT \|\|
		dma_rx_status & RX_DMA_DONE) {
		msm_geni_serial_handle_dma_rx(uport,
		drop_rx);
		if (!(dma_rx_status & RX_GENI_CANCEL_IRQ)) {
		geni_se_rx_dma_start(uport->membase,
		DMA_RX_BUF_SIZE, &msm_port->rx_dma);
		} else {
		IPC_LOG_MSG(msm_port->ipc_log_misc,
		"%s. not mapping rx dma\n",
		__func__);
		}
		}

		if (dma_rx_status & RX_SBE) {
		IPC_LOG_MSG(msm_port->ipc_log_misc,
		"%s.Rx Errors. 0x%x\n",
		__func__, dma_rx_status);
		WARN_ON(1);
		}
		if (m_irq_status & (M_CMD_CANCEL_EN \| M_CMD_ABORT_EN))
		m_cmd_done = true;

		if (dma_rx_status & (RX_EOT \| RX_GENI_CANCEL_IRQ \|
		RX_DMA_DONE))
		s_cmd_done = true;
		if (dma_rx_status)
		s_cmd_done = handle_rx_dma_xfer(s_irq_status, uport);

		if (s_irq_status & (S_CMD_CANCEL_EN \| S_CMD_ABORT_EN))
		s_cmd_done = true;
		}
		}

		exit_geni_serial_isr:
		if (m_cmd_done) {
		@@ -3386,6 +3428,9 @@ static int msm_geni_serial_probe(struct platform_device *pdev)
		if (ret)
		goto exit_wakeup_unregister;

		if (!uart_console(uport))
		spin_lock_init(&dev_port->rx_lock);

		IPC_LOG_MSG(dev_port->ipc_log_misc, "%s: port:%s irq:%d\n", __func__,
		uport->name, uport->irq);