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tty: xuartps: Move RX path into helper function
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Move RX-related IRQ handling into a helper function.
Fixes a problem where every char received after a parity or frame error
in the current isr will also be tagged as a parity or frame error.

Signed-off-by: Soren Brinkmann <[email protected]>
Reviewed-by: Peter Hurley <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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sorenb-xlnx authored and gregkh committed Feb 7, 2016
1 parent a19eda0 commit 5ede4a5
Showing 1 changed file with 28 additions and 22 deletions.
50 changes: 28 additions & 22 deletions drivers/tty/serial/xilinx_uartps.c
Original file line number Diff line number Diff line change
Expand Up @@ -172,28 +172,8 @@ struct cdns_uart {
#define to_cdns_uart(_nb) container_of(_nb, struct cdns_uart, \
clk_rate_change_nb);

/**
* cdns_uart_isr - Interrupt handler
* @irq: Irq number
* @dev_id: Id of the port
*
* Return: IRQHANDLED
*/
static irqreturn_t cdns_uart_isr(int irq, void *dev_id)
static void cdns_uart_handle_rx(struct uart_port *port, unsigned int isrstatus)
{
struct uart_port *port = (struct uart_port *)dev_id;
unsigned long flags;
unsigned int isrstatus, numbytes;
unsigned int data;
char status = TTY_NORMAL;

spin_lock_irqsave(&port->lock, flags);

/* Read the interrupt status register to determine which
* interrupt(s) is/are active.
*/
isrstatus = readl(port->membase + CDNS_UART_ISR_OFFSET);

/*
* There is no hardware break detection, so we interpret framing
* error with all-zeros data as a break sequence. Most of the time,
Expand Down Expand Up @@ -223,6 +203,9 @@ static irqreturn_t cdns_uart_isr(int irq, void *dev_id)
/* Receive Timeout Interrupt */
while (!(readl(port->membase + CDNS_UART_SR_OFFSET) &
CDNS_UART_SR_RXEMPTY)) {
u32 data;
char status = TTY_NORMAL;

data = readl(port->membase + CDNS_UART_FIFO_OFFSET);

/* Non-NULL byte after BREAK is garbage (99%) */
Expand Down Expand Up @@ -263,10 +246,33 @@ static irqreturn_t cdns_uart_isr(int irq, void *dev_id)
}

uart_insert_char(port, isrstatus, CDNS_UART_IXR_OVERRUN,
data, status);
data, status);
}
tty_flip_buffer_push(&port->state->port);
}
}

/**
* cdns_uart_isr - Interrupt handler
* @irq: Irq number
* @dev_id: Id of the port
*
* Return: IRQHANDLED
*/
static irqreturn_t cdns_uart_isr(int irq, void *dev_id)
{
struct uart_port *port = (struct uart_port *)dev_id;
unsigned long flags;
unsigned int isrstatus, numbytes;

spin_lock_irqsave(&port->lock, flags);

/* Read the interrupt status register to determine which
* interrupt(s) is/are active.
*/
isrstatus = readl(port->membase + CDNS_UART_ISR_OFFSET);

cdns_uart_handle_rx(port, isrstatus);

/* Dispatch an appropriate handler */
if ((isrstatus & CDNS_UART_IXR_TXEMPTY) == CDNS_UART_IXR_TXEMPTY) {
Expand Down

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