diff options
Diffstat (limited to 'drivers/tty/serial/msm_serial.c')
| -rw-r--r-- | drivers/tty/serial/msm_serial.c | 36 |
1 files changed, 29 insertions, 7 deletions
diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c index 1cbae0768b1f..60a9c53fa7cb 100644 --- a/drivers/tty/serial/msm_serial.c +++ b/drivers/tty/serial/msm_serial.c @@ -7,10 +7,6 @@ * Copyright (c) 2011, Code Aurora Forum. All rights reserved. */ -#if defined(CONFIG_SERIAL_MSM_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) -# define SUPPORT_SYSRQ -#endif - #include <linux/kernel.h> #include <linux/atomic.h> #include <linux/dma-mapping.h> @@ -610,7 +606,7 @@ static void msm_start_rx_dma(struct msm_port *msm_port) UARTDM_RX_SIZE, dma->dir); ret = dma_mapping_error(uart->dev, dma->phys); if (ret) - return; + goto sw_mode; dma->desc = dmaengine_prep_slave_single(dma->chan, dma->phys, UARTDM_RX_SIZE, DMA_DEV_TO_MEM, @@ -661,6 +657,22 @@ static void msm_start_rx_dma(struct msm_port *msm_port) return; unmap: dma_unmap_single(uart->dev, dma->phys, UARTDM_RX_SIZE, dma->dir); + +sw_mode: + /* + * Switch from DMA to SW/FIFO mode. After clearing Rx BAM (UARTDM_DMEN), + * receiver must be reset. + */ + msm_write(uart, UART_CR_CMD_RESET_RX, UART_CR); + msm_write(uart, UART_CR_RX_ENABLE, UART_CR); + + msm_write(uart, UART_CR_CMD_RESET_STALE_INT, UART_CR); + msm_write(uart, 0xFFFFFF, UARTDM_DMRX); + msm_write(uart, UART_CR_CMD_STALE_EVENT_ENABLE, UART_CR); + + /* Re-enable RX interrupts */ + msm_port->imr |= (UART_IMR_RXLEV | UART_IMR_RXSTALE); + msm_write(uart, msm_port->imr, UART_IMR); } static void msm_stop_rx(struct uart_port *port) @@ -1580,6 +1592,7 @@ static void __msm_console_write(struct uart_port *port, const char *s, int num_newlines = 0; bool replaced = false; void __iomem *tf; + int locked = 1; if (is_uartdm) tf = port->membase + UARTDM_TF; @@ -1592,7 +1605,13 @@ static void __msm_console_write(struct uart_port *port, const char *s, num_newlines++; count += num_newlines; - spin_lock(&port->lock); + if (port->sysrq) + locked = 0; + else if (oops_in_progress) + locked = spin_trylock(&port->lock); + else + spin_lock(&port->lock); + if (is_uartdm) msm_reset_dm_count(port, count); @@ -1628,7 +1647,9 @@ static void __msm_console_write(struct uart_port *port, const char *s, iowrite32_rep(tf, buf, 1); i += num_chars; } - spin_unlock(&port->lock); + + if (locked) + spin_unlock(&port->lock); } static void msm_console_write(struct console *co, const char *s, @@ -1801,6 +1822,7 @@ static int msm_serial_probe(struct platform_device *pdev) if (unlikely(irq < 0)) return -ENXIO; port->irq = irq; + port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_MSM_CONSOLE); platform_set_drvdata(pdev, port); |