diff options
| author | Andy Shevchenko <andriy.shevchenko@linux.intel.com> | 2016-04-04 14:35:10 (GMT) |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-04-30 16:26:55 (GMT) |
| commit | c42850f1ae7e70056f852e67bb9dddf927853b47 (patch) | |
| tree | 64c36c318b551d2af4adf692c804c1bbc091d3b0 /drivers/tty | |
| parent | 107e15fc1f8d6ef69eac5f175971252f76e82f0d (diff) | |
| download | linux-c42850f1ae7e70056f852e67bb9dddf927853b47.tar.xz | |
serial: 8250_mid: recognize interrupt source in handler
There is a special register that shows interrupt status by source. In
particular case the source can be a combination of DMA Tx, DMA Rx, and UART.
Read the register and call the handlers only for sources that request an
interrupt.
Fixes: 6ede6dcd87aa ("serial: 8250_mid: add support for DMA engine handling from UART MMIO")
Cc: stable@vger.kernel.org
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/8250/8250_mid.c | 21 |
1 files changed, 11 insertions, 10 deletions
diff --git a/drivers/tty/serial/8250/8250_mid.c b/drivers/tty/serial/8250/8250_mid.c index 7aa6ef8..ed48988 100644 --- a/drivers/tty/serial/8250/8250_mid.c +++ b/drivers/tty/serial/8250/8250_mid.c @@ -25,6 +25,7 @@ #define PCI_DEVICE_ID_INTEL_DNV_UART 0x19d8 /* Intel MID Specific registers */ +#define INTEL_MID_UART_DNV_FISR 0x08 #define INTEL_MID_UART_PS 0x30 #define INTEL_MID_UART_MUL 0x34 #define INTEL_MID_UART_DIV 0x38 @@ -90,16 +91,16 @@ static int tng_setup(struct mid8250 *mid, struct uart_port *p) static int dnv_handle_irq(struct uart_port *p) { struct mid8250 *mid = p->private_data; - int ret; - - ret = hsu_dma_irq(&mid->dma_chip, 0); - ret |= hsu_dma_irq(&mid->dma_chip, 1); - - /* For now, letting the HW generate separate interrupt for the UART */ - if (ret) - return ret; - - return serial8250_handle_irq(p, serial_port_in(p, UART_IIR)); + unsigned int fisr = serial_port_in(p, INTEL_MID_UART_DNV_FISR); + int ret = IRQ_NONE; + + if (fisr & BIT(2)) + ret |= hsu_dma_irq(&mid->dma_chip, 1); + if (fisr & BIT(1)) + ret |= hsu_dma_irq(&mid->dma_chip, 0); + if (fisr & BIT(0)) + ret |= serial8250_handle_irq(p, serial_port_in(p, UART_IIR)); + return ret; } #define DNV_DMA_CHAN_OFFSET 0x80 |