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Commit c2b92524 authored by Girish Mahadevan's avatar Girish Mahadevan
Browse files

serial: msm_geni_serial: Modify power off sequence 



For HS-UART devices, the userspace drivers control powering on/off the
port.
When these requests come in too frequently ping-ponging the port between
on and off states in quick succession can put the receive state machine of
the port in a bad state aborting/corrupting the received data.
Use delayed power-off to compensate for these cases.  Write the RX
packing and stale timeout registers only once during port setup and not
constantly during port open/close.
Also reject packets where framing/parity errors are detected.

Change-Id: Ib3e9feff5cfc12ef72d74b8f4085412c66c33b5b
Signed-off-by: default avatarGirish Mahadevan <girishm@codeaurora.org>
parent 2f89b761

drivers/tty/serial/msm_geni_serial.c

+44 −13
Original line number Diff line number Diff line
@@ -97,6 +97,9 @@ 
#define UART_START_READ		(0x1)

#define UART_PARAM		(0x1)



/* UART DMA Rx GP_IRQ_BITS */

#define UART_DMA_RX_ERRS	(GENMASK(5, 8))



#define UART_OVERSAMPLING	(32)

#define STALE_TIMEOUT		(16)

#define DEFAULT_BITS_PER_CHAR	(10)
@@ -446,7 +449,8 @@ static int msm_geni_serial_power_on(struct uart_port *uport) 


static void msm_geni_serial_power_off(struct uart_port *uport)

{

	pm_runtime_put_sync(uport->dev);

	pm_runtime_mark_last_busy(uport->dev);

	pm_runtime_put_autosuspend(uport->dev);

}



static int msm_geni_serial_poll_bit(struct uart_port *uport,
@@ -872,8 +876,6 @@ static void msm_geni_serial_start_rx(struct uart_port *uport) 
{

	unsigned int geni_s_irq_en;

	unsigned int geni_m_irq_en;

	unsigned long cfg0, cfg1;

	unsigned int rxstale = DEFAULT_BITS_PER_CHAR * STALE_TIMEOUT;

	unsigned int geni_status;

	struct msm_geni_serial_port *port = GET_DEV_PORT(uport);

	int ret;
@@ -888,11 +890,6 @@ static void msm_geni_serial_start_rx(struct uart_port *uport) 
	geni_status = geni_read_reg_nolog(uport->membase, SE_GENI_STATUS);

	if (geni_status & S_GENI_CMD_ACTIVE)

		msm_geni_serial_abort_rx(uport);



	se_get_packing_config(8, 4, false, &cfg0, &cfg1);

	geni_write_reg_nolog(cfg0, uport->membase, SE_GENI_RX_PACKING_CFG0);

	geni_write_reg_nolog(cfg1, uport->membase, SE_GENI_RX_PACKING_CFG1);

	geni_write_reg_nolog(rxstale, uport->membase, SE_UART_RX_STALE_CNT);

	geni_setup_s_cmd(uport->membase, UART_START_READ, 0);



	if (port->xfer_mode == FIFO_MODE) {
@@ -932,7 +929,8 @@ static void msm_geni_serial_start_rx(struct uart_port *uport) 
	 * go through.

	 */

	mb();

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

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

	IPC_LOG_MSG(port->ipc_log_misc, "%s 0x%x\n", __func__, geni_status);

}



static void msm_geni_serial_stop_rx(struct uart_port *uport)
@@ -948,7 +946,7 @@ static void msm_geni_serial_stop_rx(struct uart_port *uport) 
				"%s.Device is suspended.\n", __func__);

		return;

	}



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

	if (port->xfer_mode == FIFO_MODE) {

		geni_s_irq_en = geni_read_reg_nolog(uport->membase,

							SE_GENI_S_IRQ_EN);
@@ -975,7 +973,6 @@ static void msm_geni_serial_stop_rx(struct uart_port *uport) 
	if (!(geni_status & S_GENI_CMD_ACTIVE))

		return;

	msm_geni_serial_abort_rx(uport);

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

}



static int handle_rx_hs(struct uart_port *uport,
@@ -1212,6 +1209,14 @@ static irqreturn_t msm_geni_serial_isr(int isr, void *dev) 
	}



	if (!dma) {

		if ((s_irq_status & S_GP_IRQ_0_EN) ||

			(s_irq_status & S_GP_IRQ_1_EN) ||

			(s_irq_status & S_GP_IRQ_2_EN) ||

			(s_irq_status & S_GP_IRQ_3_EN)) {

			IPC_LOG_MSG(msm_port->ipc_log_misc,

				"%s.sirq 0x%x.\n", __func__, s_irq_status);

			goto exit_geni_serial_isr;

		}

		if ((s_irq_status & S_RX_FIFO_WATERMARK_EN) ||

			(s_irq_status & S_RX_FIFO_LAST_EN))

			msm_geni_serial_handle_rx(uport);
@@ -1230,6 +1235,18 @@ static irqreturn_t msm_geni_serial_isr(int isr, void *dev) 
		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);

				goto exit_geni_serial_isr;

			}

			if (dma_rx_status & UART_DMA_RX_ERRS) {

				IPC_LOG_MSG(msm_port->ipc_log_misc,

					"%s.Rx Errors.  0x%x.\n",

						__func__, dma_rx_status);

				goto exit_geni_serial_isr;

			}

			if (dma_rx_status & RX_DMA_DONE)

				msm_geni_serial_handle_dma_rx(uport);

		}
@@ -1349,9 +1366,10 @@ static int msm_geni_serial_port_setup(struct uart_port *uport) 
	int ret = 0;

	struct msm_geni_serial_port *msm_port = GET_DEV_PORT(uport);

	unsigned long cfg0, cfg1;



	unsigned int rxstale = DEFAULT_BITS_PER_CHAR * STALE_TIMEOUT;



	set_rfr_wm(msm_port);

	geni_write_reg_nolog(rxstale, uport->membase, SE_UART_RX_STALE_CNT);

	if (!uart_console(uport)) {

		/* For now only assume FIFO mode. */

		msm_port->xfer_mode = SE_DMA;
@@ -1360,6 +1378,10 @@ static int msm_geni_serial_port_setup(struct uart_port *uport) 
						SE_GENI_TX_PACKING_CFG0);

		geni_write_reg_nolog(cfg1, uport->membase,

						SE_GENI_TX_PACKING_CFG1);

		geni_write_reg_nolog(cfg0, uport->membase,

						SE_GENI_RX_PACKING_CFG0);

		geni_write_reg_nolog(cfg1, uport->membase,

						SE_GENI_RX_PACKING_CFG1);

		msm_port->handle_rx = handle_rx_hs;

		msm_port->rx_fifo = devm_kzalloc(uport->dev,

				sizeof(msm_port->rx_fifo_depth * sizeof(u32)),
@@ -1380,6 +1402,11 @@ static int msm_geni_serial_port_setup(struct uart_port *uport) 
						SE_GENI_TX_PACKING_CFG0);

		geni_write_reg_nolog(cfg1, uport->membase,

						SE_GENI_TX_PACKING_CFG1);

		se_get_packing_config(8, 4, false, &cfg0, &cfg1);

		geni_write_reg_nolog(cfg0, uport->membase,

						SE_GENI_RX_PACKING_CFG0);

		geni_write_reg_nolog(cfg1, uport->membase,

						SE_GENI_RX_PACKING_CFG1);

	}

	ret = geni_se_init(uport->membase, msm_port->rx_wm, msm_port->rx_rfr);

	if (ret) {
@@ -1805,8 +1832,10 @@ static int __init msm_geni_console_setup(struct console *co, char *options) 
		return -ENXIO;

	}



	if (!dev_port->port_setup)

	if (!dev_port->port_setup) {

		msm_geni_serial_stop_rx(uport);

		msm_geni_serial_port_setup(uport);

	}



	if (options)

		uart_parse_options(options, &baud, &parity, &bits, &flow);
@@ -2180,6 +2209,8 @@ static int msm_geni_serial_probe(struct platform_device *pdev) 
								GFP_KERNEL);

	} else {

		pm_runtime_set_suspended(&pdev->dev);

		pm_runtime_set_autosuspend_delay(&pdev->dev, 150);

		pm_runtime_use_autosuspend(&pdev->dev);

		pm_runtime_enable(&pdev->dev);

	}