ttyS1: LSR safety check engaged! - misidentification?

ttyS1: LSR safety check engaged! - misidentification?

[Christian P. Schmidt]

Hi all,

Ever since Kernel 2.6.21(rc) or so I'm plagued with this message,
disabling my serial ports that have been working perfectly from 2.6.14
till that day (and are still doing so, given that I continuously remove
the code from the source).
Actually I cannot blame the code, but it seems that on both of my
laptops the LSR is actually not readable. So, is there any plan to
remove that piece of code again, or at least change it so it can be
disabled conditionally?

Regards,
Christian

Re: ttyS1: LSR safety check engaged! - misidentification?

[Andrew Morton]

On Sun, 29 Jul 2007 18:26:58 +0300
"Christian P. Schmidt" <charlie@digadd.de> wrote:

> Hi all,
> 
> Ever since Kernel 2.6.21(rc) or so I'm plagued with this message,
> disabling my serial ports that have been working perfectly from 2.6.14
> till that day (and are still doing so, given that I continuously remove
> the code from the source).
> Actually I cannot blame the code, but it seems that on both of my
> laptops the LSR is actually not readable. So, is there any plan to
> remove that piece of code again, or at least change it so it can be
> disabled conditionally?
> 

afaict this code:

	/*
	 * At this point, there's no way the LSR could still be 0xff;
	 * if it is, then bail out, because there's likely no UART
	 * here.
	 */
	if (!(up->port.flags & UPF_BUGGY_UART) &&
	    (serial_inp(up, UART_LSR) == 0xff)) {
		printk("ttyS%d: LSR safety check engaged!\n", up->port.line);
		return -ENODEV;
	}

is unchanged since 2.6.1, so I'm unsure what change you're proposing here?