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Commit e67fd2ee authored by Karthikeyan Ramasubramanian's avatar Karthikeyan Ramasubramanian
Browse files

tty: serial: msm_geni_serial: Handle RX errors and statistics 



Currently when RX errors like parity/framing errors happen or break event
happens then the driver clears the IRQ status bits without handling the
data. The stale data inside the serial engine prevents further data
from being handled. This leaves the RX state machine in bad state.

Handle the RX errors by handling the data and drop it depending on the
error. Maintain the error statistics and log appropriately.

CRs-Fixed: 2061543
Change-Id: If2dbc57c9799ca7d13b30e837bfba457494f304a
Signed-off-by: default avatarKarthikeyan Ramasubramanian <kramasub@codeaurora.org>
parent d41da87e

drivers/tty/serial/msm_geni_serial.c

+58 −25
Original line number Diff line number Diff line
@@ -98,7 +98,9 @@ 
#define UART_PARAM		(0x1)



/* UART DMA Rx GP_IRQ_BITS */

#define UART_DMA_RX_ERRS	(GENMASK(5, 8))

#define UART_DMA_RX_PARITY_ERR	BIT(5)

#define UART_DMA_RX_ERRS	(GENMASK(5, 6))

#define UART_DMA_RX_BREAK	(GENMASK(7, 8))



#define UART_OVERSAMPLING	(32)

#define STALE_TIMEOUT		(16)
@@ -141,7 +143,8 @@ struct msm_geni_serial_port { 
	int (*handle_rx)(struct uart_port *uport,

			unsigned int rx_fifo_wc,

			unsigned int rx_last_byte_valid,

			unsigned int rx_last);

			unsigned int rx_last,

			bool drop_rx);

	struct device *wrapper_dev;

	struct se_geni_rsc serial_rsc;

	dma_addr_t tx_dma;
@@ -167,11 +170,13 @@ static struct uart_driver msm_geni_serial_hs_driver; 
static int handle_rx_console(struct uart_port *uport,

			unsigned int rx_fifo_wc,

			unsigned int rx_last_byte_valid,

			unsigned int rx_last);

			unsigned int rx_last,

			bool drop_rx);

static int handle_rx_hs(struct uart_port *uport,

			unsigned int rx_fifo_wc,

			unsigned int rx_last_byte_valid,

			unsigned int rx_last);

			unsigned int rx_last,

			bool drop_rx);

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);
@@ -681,7 +686,8 @@ static void msm_geni_serial_console_write(struct console *co, const char *s, 
static int handle_rx_console(struct uart_port *uport,

			unsigned int rx_fifo_wc,

			unsigned int rx_last_byte_valid,

			unsigned int rx_last)

			unsigned int rx_last,

			bool drop_rx)

{

	int i, c;

	unsigned char *rx_char;
@@ -694,6 +700,8 @@ static int handle_rx_console(struct uart_port *uport, 


		*(msm_port->rx_fifo) =

			geni_read_reg_nolog(uport->membase, SE_GENI_RX_FIFOn);

		if (drop_rx)

			continue;

		rx_char = (unsigned char *)msm_port->rx_fifo;



		if (i == (rx_fifo_wc - 1)) {
@@ -710,6 +718,7 @@ static int handle_rx_console(struct uart_port *uport, 
				tty_insert_flip_char(tport, rx_char[c], flag);

		}

	}

	if (!drop_rx)

		tty_flip_buffer_push(tport);

	return 0;

}
@@ -717,7 +726,8 @@ static int handle_rx_console(struct uart_port *uport, 
static int handle_rx_console(struct uart_port *uport,

			unsigned int rx_fifo_wc,

			unsigned int rx_last_byte_valid,

			unsigned int rx_last)

			unsigned int rx_last,

			bool drop_rx)

{

	return -EPERM;

}
@@ -1001,7 +1011,8 @@ static void msm_geni_serial_stop_rx(struct uart_port *uport) 
static int handle_rx_hs(struct uart_port *uport,

			unsigned int rx_fifo_wc,

			unsigned int rx_last_byte_valid,

			unsigned int rx_last)

			unsigned int rx_last,

			bool drop_rx)

{

	unsigned char *rx_char;

	struct tty_port *tport;
@@ -1016,6 +1027,8 @@ static int handle_rx_hs(struct uart_port *uport, 
	tport = &uport->state->port;

	ioread32_rep((uport->membase + SE_GENI_RX_FIFOn), msm_port->rx_fifo,

								rx_fifo_wc);

	if (drop_rx)

		return 0;



	rx_char = (unsigned char *)msm_port->rx_fifo;

	ret = tty_insert_flip_string(tport, rx_char, rx_bytes);
@@ -1031,7 +1044,7 @@ static int handle_rx_hs(struct uart_port *uport, 
	return ret;

}



static int msm_geni_serial_handle_rx(struct uart_port *uport)

static int msm_geni_serial_handle_rx(struct uart_port *uport, bool drop_rx)

{

	int ret = 0;

	unsigned int rx_fifo_status;
@@ -1050,7 +1063,7 @@ static int msm_geni_serial_handle_rx(struct uart_port *uport) 
	rx_last = rx_fifo_status & RX_LAST;

	if (rx_fifo_wc)

		port->handle_rx(uport, rx_fifo_wc, rx_last_byte_valid,

								rx_last);

							rx_last, drop_rx);

	return ret;

}
@@ -1128,13 +1141,13 @@ static int msm_geni_serial_handle_tx(struct uart_port *uport) 
	} else {

		msm_port->xmit_size = xmit_size;

	}

exit_handle_tx:

	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)

		uart_write_wakeup(uport);

exit_handle_tx:

	return ret;

}



static int msm_geni_serial_handle_dma_rx(struct uart_port *uport)

static int msm_geni_serial_handle_dma_rx(struct uart_port *uport, bool drop_rx)

{

	struct msm_geni_serial_port *msm_port = GET_DEV_PORT(uport);

	unsigned int rx_bytes = 0;
@@ -1160,6 +1173,8 @@ static int msm_geni_serial_handle_dma_rx(struct uart_port *uport) 
					__func__, rx_bytes);

		goto exit_handle_dma_rx;

	}

	if (drop_rx)

		goto exit_handle_dma_rx;



	tport = &uport->state->port;

	ret = tty_insert_flip_string(tport, (unsigned char *)(msm_port->rx_buf),
@@ -1211,6 +1226,7 @@ static irqreturn_t msm_geni_serial_isr(int isr, void *dev) 
	unsigned long flags;

	unsigned int m_irq_en;

	struct msm_geni_serial_port *msm_port = GET_DEV_PORT(uport);

	bool drop_rx = false;



	spin_lock_irqsave(&uport->lock, flags);

	if (uart_console(uport) && uport->suspended)
@@ -1239,21 +1255,29 @@ static irqreturn_t msm_geni_serial_isr(int isr, void *dev) 
	}



	if (!dma) {

		if ((m_irq_status & m_irq_en) &

		    (M_TX_FIFO_WATERMARK_EN | M_CMD_DONE_EN))

			msm_geni_serial_handle_tx(uport);



		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_1_EN)) {

			if (s_irq_status & S_GP_IRQ_0_EN)

				uport->icount.parity++;

			IPC_LOG_MSG(msm_port->ipc_log_misc,

				"%s.sirq 0x%x parity:%d\n",

				__func__, s_irq_status, uport->icount.parity);

			drop_rx = true;

		} else if ((s_irq_status & S_GP_IRQ_2_EN) ||

			(s_irq_status & S_GP_IRQ_3_EN)) {

			uport->icount.brk++;

			IPC_LOG_MSG(msm_port->ipc_log_misc,

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

			goto exit_geni_serial_isr;

				"%s.sirq 0x%x break:%d\n",

				__func__, s_irq_status, uport->icount.brk);

		}



		if ((s_irq_status & S_RX_FIFO_WATERMARK_EN) ||

			(s_irq_status & S_RX_FIFO_LAST_EN))

			msm_geni_serial_handle_rx(uport);



		if ((m_irq_status & m_irq_en) &

		    (M_TX_FIFO_WATERMARK_EN | M_CMD_DONE_EN))

			msm_geni_serial_handle_tx(uport);

			msm_geni_serial_handle_rx(uport, drop_rx);

	} else {

		if (dma_tx_status) {

			geni_write_reg_nolog(dma_tx_status, uport->membase,
@@ -1272,13 +1296,22 @@ static irqreturn_t msm_geni_serial_isr(int isr, void *dev) 
				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.\n",

						__func__, dma_rx_status);

				goto exit_geni_serial_isr;

					"%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_DMA_DONE)

				msm_geni_serial_handle_dma_rx(uport);

				msm_geni_serial_handle_dma_rx(uport, drop_rx);

		}

	}