On Sat, Nov 10, 2012 at 5:24 PM, Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> wrote:
> On Sat, 10 Nov 2012 11:52:32 -0600
> Matt Schulte <matts@xxxxxxxxxxxxxxxxxxxx> wrote:
>
>> On Fri, Nov 9, 2012 at 5:58 PM, Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> wrote:
>> >> @@ -1484,6 +1526,7 @@ EXPORT_SYMBOL_GPL(serial8250_modem_status);
>> >> int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
>> >> {
>> >> unsigned char status;
>> >> + unsigned char int0, int1, int2, int3;
>> >> unsigned long flags;
>> >> struct uart_8250_port *up =
>> >> container_of(port, struct uart_8250_port, port);
>> >> @@ -1503,6 +1546,19 @@ int serial8250_handle_irq(struct uart_port
>> >> *port, unsigned int iir)
>> >> if (status & UART_LSR_THRE)
>> >> serial8250_tx_chars(up);
>> >>
>> >> + /*
>> >> + * These Exar UARTs have an extra interrupt indicator that could
>> >> + * fire for a few unimplemented interrupts. Put this here just
>> >> + * to be on the safe side that these interrupts don't go unhandled.
>> >> + */
>> >> +
>> >> + if (up->port.type == PORT_XR17V35X && status == 0) {
>> >> + int0 = serial_port_in(port, 0x80);
>> >> + int1 = serial_port_in(port, 0x81);
>> >> + int2 = serial_port_in(port, 0x82);
>> >> + int3 = serial_port_in(port, 0x83);
>> >> + }
>> >> +
>> >> spin_unlock_irqrestore(&port->lock, flags);
>> >> return 1;
>> >
>> > Provide your own handle_irq method rather than adding more special cases
>> > to the default one (you can just wrap the default one and then perform
>> > the extra actions). Just a case of trying to keep the fast paths clean and
>> > maintainable.
>> >
>> > Otherwise looks good.
>> >
>> > Alan
>>
>> Thanks Alan, would the new Exar_handle_irq method be allowed to be
>> inside 8250.c?
>
> If its probed generically then it probably should - we can move it later
> anyway
>
I'm having trouble figuring out where would be the right place to override the
uart_port.handle_irq = serial8250_default_handle_irq
with my
uart_port.handle_irq = exar_handle_irq
Can you give me a tip as to where in 8250.c this should be done?
Thank you,
Matt Schulte
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