[PATCH] serial: do not add port that is not initialized

[PATCH] serial: do not add port that is not initialized

[Yinghai Lu]

[PATCH] serial: do not add port that is not initialized

if the port is not initialized with correct iobase, and membase, we don't
need to add that port.
for x86, when pnpacpi is enabled, we will not get extra ttyS1/ttyS2/ttyS3 in
/sys/devices/platform/serial8250/tty

Sign-off-by: Yinghai Lu <yinghai.lu@sun.com>

diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index c84dab0..6399014 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -2425,9 +2425,12 @@ serial8250_register_ports(struct uart_driver *drv, struct device *dev)
 	for (i = 0; i < nr_uarts; i++) {
 		struct uart_8250_port *up = &serial8250_ports[i];
 
+		if (!up->port.iobase && !up->port.membase)
+			continue;
 		up->port.dev = dev;
 		uart_add_one_port(drv, &up->port);
 	}
+
 }
 
 #ifdef CONFIG_SERIAL_8250_CONSOLE

Re: [PATCH] serial: do not add port that is not initialized

[Russell King]

On Tue, Jul 10, 2007 at 05:03:35PM -0700, Yinghai Lu wrote:
> [PATCH] serial: do not add port that is not initialized
> 
> if the port is not initialized with correct iobase, and membase, we don't
> need to add that port.
> for x86, when pnpacpi is enabled, we will not get extra ttyS1/ttyS2/ttyS3 in
> /sys/devices/platform/serial8250/tty
> 
> Sign-off-by: Yinghai Lu <yinghai.lu@sun.com>

What if someone wants to run setserial on /dev/ttyS1 to set it's base
address, irq and other parameters?  People still do this.

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:

Re: [PATCH] serial: do not add port that is not initialized

[Bjorn Helgaas]

On Wednesday 11 July 2007 01:17:42 am Russell King wrote:
> On Tue, Jul 10, 2007 at 05:03:35PM -0700, Yinghai Lu wrote:
> > [PATCH] serial: do not add port that is not initialized
> > 
> > if the port is not initialized with correct iobase, and membase, we don't
> > need to add that port.
> > for x86, when pnpacpi is enabled, we will not get extra ttyS1/ttyS2/ttyS3 in
> > /sys/devices/platform/serial8250/tty
> > 
> > Sign-off-by: Yinghai Lu <yinghai.lu@sun.com>
> 
> What if someone wants to run setserial on /dev/ttyS1 to set it's base
> address, irq and other parameters?  People still do this.

I agree that people still use setserial that way, and we shouldn't
make this change because it would break things.

But I also agree with Yinghai that these extra phantom devices are
just weird.  It would be a lot nicer if there were a way to say,
"please, Mr. Serial Driver, create me a new ttyS device with these
parameters."

But no, I'm not volunteering to do that.

Bjorn

Re: [PATCH] serial: do not add port that is not initialized

[Russell King]

On Wed, Jul 11, 2007 at 10:05:53AM -0600, Bjorn Helgaas wrote:
> On Wednesday 11 July 2007 01:17:42 am Russell King wrote:
> > On Tue, Jul 10, 2007 at 05:03:35PM -0700, Yinghai Lu wrote:
> > > [PATCH] serial: do not add port that is not initialized
> > > 
> > > if the port is not initialized with correct iobase, and membase, we don't
> > > need to add that port.
> > > for x86, when pnpacpi is enabled, we will not get extra ttyS1/ttyS2/ttyS3 in
> > > /sys/devices/platform/serial8250/tty
> > > 
> > > Sign-off-by: Yinghai Lu <yinghai.lu@sun.com>
> > 
> > What if someone wants to run setserial on /dev/ttyS1 to set it's base
> > address, irq and other parameters?  People still do this.
> 
> I agree that people still use setserial that way, and we shouldn't
> make this change because it would break things.
> 
> But I also agree with Yinghai that these extra phantom devices are
> just weird.  It would be a lot nicer if there were a way to say,
> "please, Mr. Serial Driver, create me a new ttyS device with these
> parameters."
> 
> But no, I'm not volunteering to do that.

Indeed, and since distros still haven't picked up my setserial v3,
I see little chance of that ever being practical.  Not that I've
really tried very hard to get them to - no real idea who to contact
to make that happen, and of course I've no interest in making it
happen anymore.

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:

Re: [PATCH] serial: do not add port that is not initialized

[Yinghai Lu]

Russell King wrote:
> On Wed, Jul 11, 2007 at 10:05:53AM -0600, Bjorn Helgaas wrote:
>> On Wednesday 11 July 2007 01:17:42 am Russell King wrote:
>>> On Tue, Jul 10, 2007 at 05:03:35PM -0700, Yinghai Lu wrote:
>>>> [PATCH] serial: do not add port that is not initialized
>>>>
>>>> if the port is not initialized with correct iobase, and membase, we don't
>>>> need to add that port.
>>>> for x86, when pnpacpi is enabled, we will not get extra ttyS1/ttyS2/ttyS3 in
>>>> /sys/devices/platform/serial8250/tty
>>>>
>>>> Sign-off-by: Yinghai Lu <yinghai.lu@sun.com>
>>> What if someone wants to run setserial on /dev/ttyS1 to set it's base
>>> address, irq and other parameters?  People still do this.
>> I agree that people still use setserial that way, and we shouldn't
>> make this change because it would break things.
>>
>> But I also agree with Yinghai that these extra phantom devices are
>> just weird.  It would be a lot nicer if there were a way to say,
>> "please, Mr. Serial Driver, create me a new ttyS device with these
>> parameters."
>>
>> But no, I'm not volunteering to do that.
> 
> Indeed, and since distros still haven't picked up my setserial v3,
> I see little chance of that ever being practical.  Not that I've
> really tried very hard to get them to - no real idea who to contact
> to make that happen, and of course I've no interest in making it
> happen anymore.

so remove these extra phantom devices, the kernel distros will use your setserial v3.

we can put some comments in code, so later they will find clue about your setserial v3.

YH

Re: [PATCH] serial: do not add port that is not initialized

[Russell King]

On Wed, Jul 11, 2007 at 01:45:04PM -0700, Yinghai Lu wrote:
> Russell King wrote:
> >Indeed, and since distros still haven't picked up my setserial v3,
> >I see little chance of that ever being practical.  Not that I've
> >really tried very hard to get them to - no real idea who to contact
> >to make that happen, and of course I've no interest in making it
> >happen anymore.
> 
> so remove these extra phantom devices, the kernel distros will use your 
> setserial v3.

You made a connection which wasn't there - setserial v3 doesn't allow
this either, but it is a cleaner and slightly more extensible
implementation of setserial v2.

It does, however, drop support for the things which 2.6 kernels don't
support, such as the setting of the multiport addresses and masks.  So
it wouldn't be suitable for shipping as-is with (eg) 2.4 kernels.

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of: