Re: sysrq on serial console

Russell King
2002-09-28T08:00:59Z

On Fri, Sep 27, 2002 at 04:45:12PM -0700, Dave Hansen wrote:
> It looks like the UART_LSR_BI bit needs to be set in the status
> variable for the break character to be interpreted as a break in the
> driver.

That is correct; that is how the UART reports a break character.

> I doubt that it is actually broken, but it isn't immediately obvious
> how that bit gets set. Is there something that I should have set when
> the device was initialized to make sure that UART_LSR_BI is asserted
> in "status" when the interrupt occurs?

Now. Its a status bit from the UART LSR register itself, read from
serial8250_handle_port() and receive_chars(). It will cause an
interrupt any time that the receive interrupt is enabled, ie when
the port is open by user space.

--
Russell King (rmk@arm.linux.org.uk) The developer of ARM Linux