Re: sysrq on serial console

Russell King (rmk@arm.linux.org.uk)
Sat, 28 Sep 2002 09:06:17 +0100

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
             http://www.arm.linux.org.uk/personal/aboutme.html


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