diff options
| -rw-r--r-- | drivers/tty/serial/8250/8250_dw.c | 37 |
1 files changed, 21 insertions, 16 deletions
diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c index f47ede4d1968..abf0814086a5 100644 --- a/drivers/tty/serial/8250/8250_dw.c +++ b/drivers/tty/serial/8250/8250_dw.c @@ -9,6 +9,9 @@ * LCR is written whilst busy. If it is, then a busy detect interrupt is * raised, the LCR needs to be rewritten and the uart status register read. */ +#include <linux/bitfield.h> +#include <linux/bits.h> +#include <linux/cleanup.h> #include <linux/clk.h> #include <linux/delay.h> #include <linux/device.h> @@ -40,6 +43,8 @@ #define RZN1_UART_RDMACR 0x110 /* DMA Control Register Receive Mode */ /* DesignWare specific register fields */ +#define DW_UART_IIR_IID GENMASK(3, 0) + #define DW_UART_MCR_SIRE BIT(6) /* Renesas specific register fields */ @@ -312,7 +317,19 @@ static int dw8250_handle_irq(struct uart_port *p) bool rx_timeout = (iir & 0x3f) == UART_IIR_RX_TIMEOUT; unsigned int quirks = d->pdata->quirks; unsigned int status; - unsigned long flags; + + switch (FIELD_GET(DW_UART_IIR_IID, iir)) { + case UART_IIR_NO_INT: + return 0; + + case UART_IIR_BUSY: + /* Clear the USR */ + serial_port_in(p, d->pdata->usr_reg); + + return 1; + } + + guard(uart_port_lock_irqsave)(p); /* * There are ways to get Designware-based UARTs into a state where @@ -325,20 +342,15 @@ static int dw8250_handle_irq(struct uart_port *p) * so we limit the workaround only to non-DMA mode. */ if (!up->dma && rx_timeout) { - uart_port_lock_irqsave(p, &flags); status = serial_lsr_in(up); if (!(status & (UART_LSR_DR | UART_LSR_BI))) serial_port_in(p, UART_RX); - - uart_port_unlock_irqrestore(p, flags); } /* Manually stop the Rx DMA transfer when acting as flow controller */ if (quirks & DW_UART_QUIRK_IS_DMA_FC && up->dma && up->dma->rx_running && rx_timeout) { - uart_port_lock_irqsave(p, &flags); status = serial_lsr_in(up); - uart_port_unlock_irqrestore(p, flags); if (status & (UART_LSR_DR | UART_LSR_BI)) { dw8250_writel_ext(p, RZN1_UART_RDMACR, 0); @@ -346,17 +358,9 @@ static int dw8250_handle_irq(struct uart_port *p) } } - if (serial8250_handle_irq(p, iir)) - return 1; - - if ((iir & UART_IIR_BUSY) == UART_IIR_BUSY) { - /* Clear the USR */ - serial_port_in(p, d->pdata->usr_reg); + serial8250_handle_irq_locked(p, iir); - return 1; - } - - return 0; + return 1; } static void dw8250_clk_work_cb(struct work_struct *work) @@ -867,6 +871,7 @@ static struct platform_driver dw8250_platform_driver = { module_platform_driver(dw8250_platform_driver); +MODULE_IMPORT_NS("SERIAL_8250"); MODULE_AUTHOR("Jamie Iles"); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("Synopsys DesignWare 8250 serial port driver"); |