We need to issue a reset if we ever change the value of the IPR register on DM hardware. If we don't reset the hardware the RX stale interrupt never triggers and the only way to trigger an RX handling event is by filling up the fifo. This causes things like getty to not work so well considering it might change the baud rate a few times. Fix this by moving the reset on startup and any reprogramming required after the reset to be after we change the baud rate. Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx> --- This is based on my latest two patches to fix the break handling in this driver[1]. The only conflict is the break start interrupt bit so it could be moved off that patch if desired. This doesn't seem to affect non-DM hardware one way or the other, but I also can't get a getty to work on non-DM hardware right now. I need to debug that more some time. [1] http://lkml.kernel.org/r/1414606478-13709-1-git-send-email-sboyd@xxxxxxxxxxxxxx drivers/tty/serial/msm_serial.c | 49 ++++++++++------------------------------- 1 file changed, 12 insertions(+), 37 deletions(-) diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c index d44c04976f7a..b507f5a16c1c 100644 --- a/drivers/tty/serial/msm_serial.c +++ b/drivers/tty/serial/msm_serial.c @@ -427,9 +427,6 @@ static int msm_set_baud_rate(struct uart_port *port, unsigned int baud) entry = msm_find_best_baud(port, baud); - if (msm_port->is_uartdm) - msm_write(port, UART_CR_CMD_RESET_RX, UART_CR); - msm_write(port, entry->code, UART_CSR); /* RX stale watermark */ @@ -446,6 +443,18 @@ static int msm_set_baud_rate(struct uart_port *port, unsigned int baud) /* set TX watermark */ msm_write(port, 10, UART_TFWR); + msm_write(port, UART_CR_CMD_PROTECTION_EN, UART_CR); + msm_reset(port); + + /* Enable RX and TX */ + msm_write(port, UART_CR_TX_ENABLE | UART_CR_RX_ENABLE, UART_CR); + + /* turn on RX and CTS interrupts */ + msm_port->imr = UART_IMR_RXLEV | UART_IMR_RXSTALE | + UART_IMR_CURRENT_CTS | UART_IMR_RXBREAK_START; + + msm_write(port, msm_port->imr, UART_IMR); + if (msm_port->is_uartdm) { msm_write(port, UART_CR_CMD_RESET_STALE_INT, UART_CR); msm_write(port, 0xFFFFFF, UARTDM_DMRX); @@ -492,40 +501,6 @@ static int msm_startup(struct uart_port *port) data |= UART_MR1_AUTO_RFR_LEVEL1 & (rfr_level << 2); data |= UART_MR1_AUTO_RFR_LEVEL0 & rfr_level; msm_write(port, data, UART_MR1); - - /* make sure that RXSTALE count is non-zero */ - data = msm_read(port, UART_IPR); - if (unlikely(!data)) { - data |= UART_IPR_RXSTALE_LAST; - data |= UART_IPR_STALE_LSB; - msm_write(port, data, UART_IPR); - } - - data = 0; - if (!port->cons || (port->cons && !(port->cons->flags & CON_ENABLED))) { - msm_write(port, UART_CR_CMD_PROTECTION_EN, UART_CR); - msm_reset(port); - data = UART_CR_TX_ENABLE; - } - - data |= UART_CR_RX_ENABLE; - msm_write(port, data, UART_CR); /* enable TX & RX */ - - /* Make sure IPR is not 0 to start with*/ - if (msm_port->is_uartdm) - msm_write(port, UART_IPR_STALE_LSB, UART_IPR); - - /* turn on RX and CTS interrupts */ - msm_port->imr = UART_IMR_RXLEV | UART_IMR_RXSTALE | - UART_IMR_CURRENT_CTS | UART_IMR_RXBREAK_START; - - if (msm_port->is_uartdm) { - msm_write(port, 0xFFFFFF, UARTDM_DMRX); - msm_write(port, UART_CR_CMD_RESET_STALE_INT, UART_CR); - msm_write(port, UART_CR_CMD_STALE_EVENT_ENABLE, UART_CR); - } - - msm_write(port, msm_port->imr, UART_IMR); return 0; } -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
