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Commit a4ed0388 authored by Girish Mahadevan's avatar Girish Mahadevan
Browse files

serial: msm_geni_serial: Modify console iterations and hs uart ioctls 



For console usecases don't compute the poll iterations based on baud rate
rather just poll for a constant number of iterations.
Fix a bug where a cancel was being called on the secondary sequencer
instead of the primary, when the tx needed to be cancelled.
Modify the early console and console setup procedures to be more
consistent.
Add a defensive check to the ioctls to protect against imbalanced votes
from userspace (where in there are more clk_offs than clk_ons).

Change-Id: I8e7947e27d399f8c9a9b8f2cb6affb11c4051cd6
Signed-off-by: default avatarGirish Mahadevan <girishm@codeaurora.org>
parent d56766f7

drivers/tty/serial/msm_geni_serial.c

+74 −65
Original line number Diff line number Diff line
@@ -145,6 +145,7 @@ struct msm_geni_serial_port { 
	void *ipc_log_pwr;

	void *ipc_log_misc;

	unsigned int cur_baud;

	int ioctl_count;

};



static const struct uart_ops msm_geni_serial_pops;
@@ -161,6 +162,8 @@ static int handle_rx_hs(struct uart_port *uport, 
static unsigned int msm_geni_serial_tx_empty(struct uart_port *port);

static int msm_geni_serial_power_on(struct uart_port *uport);

static void msm_geni_serial_power_off(struct uart_port *uport);

static int msm_geni_serial_poll_bit(struct uart_port *uport,

				int offset, int bit_field, bool set);



static atomic_t uart_line_id = ATOMIC_INIT(0);
@@ -218,22 +221,22 @@ static void dump_ipc(void *ipc_ctx, char *prefix, char *string, 
					(unsigned int)addr, size, buf);

}



static void check_tx_active(struct uart_port *uport)

static bool check_tx_active(struct uart_port *uport)

{

	u32 geni_status = geni_read_reg_nolog(uport->membase,

					SE_GENI_STATUS);



	while ((geni_status & M_GENI_CMD_ACTIVE)) {

		cpu_relax();

		geni_status = geni_read_reg_nolog(uport->membase,

					SE_GENI_STATUS);

	}

	/*

	 * Poll if the GENI STATUS bit for TX is cleared. If the bit is

	 * clear (poll condition met), return false, meaning tx isn't active

	 * else return true. So return not of the poll return.

	 */

	return !msm_geni_serial_poll_bit(uport, SE_GENI_STATUS,

					M_GENI_CMD_ACTIVE, false);

}



static int vote_clock_on(struct uart_port *uport)

{

	int ret = 0;

	struct msm_geni_serial_port *port = GET_DEV_PORT(uport);

	int usage_count = atomic_read(&uport->dev->power.usage_count);



	if (!pm_runtime_enabled(uport->dev)) {

		dev_err(uport->dev, "RPM not available.Can't enable clocks\n");
@@ -245,8 +248,10 @@ static int vote_clock_on(struct uart_port *uport) 
		dev_err(uport->dev, "Failed to vote clock on\n");

		return ret;

	}

	port->ioctl_count++;

	__pm_relax(&port->geni_wake);

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

	IPC_LOG_MSG(port->ipc_log_pwr, "%s rpm %d ioctl %d\n",

				__func__, usage_count, port->ioctl_count);

	return 0;

}
@@ -254,16 +259,29 @@ static int vote_clock_off(struct uart_port *uport) 
{

	struct msm_geni_serial_port *port = GET_DEV_PORT(uport);

	int ret = 0;

	int usage_count = atomic_read(&uport->dev->power.usage_count);



	if (!pm_runtime_enabled(uport->dev)) {

		dev_err(uport->dev, "RPM not available.Can't enable clocks\n");

		ret = -EPERM;

		return ret;

	}

	/* Block till any on going Tx goes out.*/

	check_tx_active(uport);

	/* Check on going Tx. Don't block on this for now. */

	if (check_tx_active(uport))

		dev_warn(uport->dev, "%s: Vote off called during active Tx",

								__func__);

	if (!port->ioctl_count) {

		dev_warn(uport->dev, "%s:Imbalanced vote off ioctl %d\n",

						 __func__, usage_count);

		IPC_LOG_MSG(port->ipc_log_pwr,

				"%s:Imbalanced vote_off from userspace rpm%d",

				__func__, usage_count);

		return 0;

	}

	port->ioctl_count--;

	msm_geni_serial_power_off(uport);

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

	IPC_LOG_MSG(port->ipc_log_pwr, "%s rpm %d ioctl %d\n",

				__func__, usage_count, port->ioctl_count);

	return 0;

};
@@ -398,20 +416,20 @@ static int msm_geni_serial_poll_bit(struct uart_port *uport, 
	bool cond = false;

	unsigned int baud = 115200;

	unsigned int fifo_bits = DEF_FIFO_DEPTH_WORDS * DEF_FIFO_WIDTH_BITS;

	unsigned long total_iter = 0;

	unsigned long total_iter = 1000;





	if (uport->private_data) {

	if (uport->private_data && !uart_console(uport)) {

		port = GET_DEV_PORT(uport);

		baud = (port->cur_baud ? port->cur_baud : 115200);

		fifo_bits = port->tx_fifo_depth * port->tx_fifo_width;

	}

		/*

		 * Total polling iterations based on FIFO worth of bytes to be

		 * sent at current baud .Add a little fluff to the wait.

		 */

		total_iter = ((fifo_bits * USEC_PER_SEC) / baud);

		total_iter += 50;

	}



	while (iter < total_iter) {

		reg = geni_read_reg_nolog(uport->membase, offset);
@@ -449,18 +467,12 @@ static void msm_geni_serial_poll_cancel_tx(struct uart_port *uport) 
	done = msm_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,

						M_CMD_DONE_EN, true);

	if (!done) {

		geni_write_reg_nolog(M_GENI_CMD_CANCEL, uport->membase,

						SE_GENI_S_CMD_CTRL_REG);

		irq_clear |= M_CMD_CANCEL_EN;

		if (!msm_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,

						M_CMD_CANCEL_EN, true)) {

		geni_write_reg_nolog(M_GENI_CMD_ABORT, uport->membase,

					SE_GENI_M_CMD_CTRL_REG);

		irq_clear |= M_CMD_ABORT_EN;

		msm_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,

							M_CMD_ABORT_EN, true);

	}

	}

	geni_write_reg_nolog(irq_clear, uport->membase, SE_GENI_M_IRQ_CLEAR);

}
@@ -678,7 +690,6 @@ static void msm_geni_serial_start_tx(struct uart_port *uport) 
	geni_write_reg_nolog(geni_m_irq_en, uport->membase, SE_GENI_M_IRQ_EN);

	/* Geni command setup/irq enables should complete before returning.*/

	mb();

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

}



static void msm_geni_serial_stop_tx(struct uart_port *uport)
@@ -1032,8 +1043,25 @@ static int msm_geni_serial_port_setup(struct uart_port *uport) 
	if (!uart_console(uport)) {

		/* For now only assume FIFO mode. */

		msm_port->xfer_mode = FIFO_MODE;

		ret = geni_se_init(uport->membase,

					msm_port->rx_wm, msm_port->rx_rfr);

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

		geni_write_reg_nolog(cfg0, uport->membase,

						SE_GENI_TX_PACKING_CFG0);

		geni_write_reg_nolog(cfg1, uport->membase,

						SE_GENI_TX_PACKING_CFG1);

	} else {

		/*

		 * Make an unconditional cancel on the main sequencer to reset

		 * it else we could end up in data loss scenarios.

		 */

		msm_port->xfer_mode = FIFO_MODE;

		msm_geni_serial_poll_cancel_tx(uport);

		se_get_packing_config(8, 1, false, &cfg0, &cfg1);

		geni_write_reg_nolog(cfg0, uport->membase,

						SE_GENI_TX_PACKING_CFG0);

		geni_write_reg_nolog(cfg1, uport->membase,

						SE_GENI_TX_PACKING_CFG1);

	}

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

	if (ret) {

		dev_err(uport->dev, "%s: Fail\n", __func__);

		goto exit_portsetup;
@@ -1043,13 +1071,6 @@ static int msm_geni_serial_port_setup(struct uart_port *uport) 
	if (ret)

		goto exit_portsetup;



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

		geni_write_reg_nolog(cfg0, uport->membase,

						SE_GENI_TX_PACKING_CFG0);

		geni_write_reg_nolog(cfg1, uport->membase,

						SE_GENI_TX_PACKING_CFG1);

	}



	msm_port->port_setup = true;

	/*

	 * Ensure Port setup related IO completes before returning to
@@ -1118,13 +1139,11 @@ static int msm_geni_serial_startup(struct uart_port *uport) 
	if (unlikely(get_se_proto(uport->membase) != UART)) {

		dev_err(uport->dev, "%s: Invalid FW %d loaded.\n",

				 __func__, get_se_proto(uport->membase));

		if (unlikely(get_se_proto(uport->membase) != UART)) {

		ret = -ENXIO;

		disable_irq(uport->irq);

		free_irq(uport->irq, msm_port);

		goto exit_startup;

	}

	}



	if (!msm_port->port_setup) {

		if (msm_geni_serial_port_setup(uport))
@@ -1358,7 +1377,6 @@ static int __init msm_geni_console_setup(struct console *co, char *options) 
	int parity = 'n';

	int flow = 'n';

	int ret = 0;

	unsigned long cfg0, cfg1;



	if (unlikely(co->index >= GENI_UART_NR_PORTS  || co->index < 0))

		return -ENXIO;
@@ -1386,14 +1404,6 @@ static int __init msm_geni_console_setup(struct console *co, char *options) 
	if (!dev_port->port_setup)

		msm_geni_serial_port_setup(uport);



	/*

	 * Make an unconditional cancel on the main sequencer to reset

	 * it else we could end up in data loss scenarios.

	 */

	msm_geni_serial_poll_cancel_tx(uport);

	se_get_packing_config(8, 1, false, &cfg0, &cfg1);

	geni_write_reg_nolog(cfg0, uport->membase, SE_GENI_TX_PACKING_CFG0);

	geni_write_reg_nolog(cfg1, uport->membase, SE_GENI_TX_PACKING_CFG1);

	if (options)

		uart_parse_options(options, &baud, &parity, &bits, &flow);
@@ -1438,9 +1448,6 @@ msm_geni_serial_earlycon_setup(struct earlycon_device *dev, 
		goto exit_geni_serial_earlyconsetup;

	}



	geni_se_init(uport->membase, (DEF_FIFO_DEPTH_WORDS >> 1),

					(DEF_FIFO_DEPTH_WORDS - 2));

	geni_se_select_mode(uport->membase, FIFO_MODE);

	/*

	 * Ignore Flow control.

	 * Disable Tx Parity.
@@ -1471,7 +1478,11 @@ msm_geni_serial_earlycon_setup(struct earlycon_device *dev, 
	 * it else we could end up in data loss scenarios.

	 */

	msm_geni_serial_poll_cancel_tx(uport);

	msm_geni_serial_abort_rx(uport);

	se_get_packing_config(8, 1, false, &cfg0, &cfg1);

	geni_se_init(uport->membase, (DEF_FIFO_DEPTH_WORDS >> 1),

					(DEF_FIFO_DEPTH_WORDS - 2));

	geni_se_select_mode(uport->membase, FIFO_MODE);

	geni_write_reg_nolog(cfg0, uport->membase, SE_GENI_TX_PACKING_CFG0);

	geni_write_reg_nolog(cfg1, uport->membase, SE_GENI_TX_PACKING_CFG1);

	geni_write_reg_nolog(tx_trans_cfg, uport->membase,
@@ -1802,8 +1813,7 @@ static int msm_geni_serial_runtime_suspend(struct device *dev) 
	}

	if (port->wakeup_irq > 0)

		enable_irq(port->wakeup_irq);

	IPC_LOG_MSG(port->ipc_log_pwr, "%s: Current usage count %d\n", __func__,

				atomic_read(&dev->power.usage_count));

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

exit_runtime_suspend:

	return ret;

}
@@ -1821,8 +1831,7 @@ static int msm_geni_serial_runtime_resume(struct device *dev) 
		dev_err(dev, "%s: Error ret %d\n", __func__, ret);

		goto exit_runtime_resume;

	}

	IPC_LOG_MSG(port->ipc_log_pwr, "%s: Current usage count %d\n", __func__,

				atomic_read(&dev->power.usage_count));

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

exit_runtime_resume:

	return ret;

}