pppd and 2.6.25 serial driver

pppd and 2.6.25 serial driver

[Chris Vine]

Because I have had to resort to using dial-up this weekend, I noticed
that the serial driver for the 8250/16550 UART in the 2.6.25 kernel does
not work correctly with ppp-2.4.4. After establishing a dial-up modem
connection it becomes unresponsive and pppd will exit waiting to
establish a ppp connection after sending LCP configuration requests.  I
have tested this with two different dial-up modems and at two different
dial-up providers, with the 2.6.25.3 and 2.6.25.4 kernels.

pppd works fine with the 2.6.25 kernel if the serial driver is not used
(for example if establishing a ppp connection over (in kernel) ATM or
via an (out of kernel tree) softmodem driver I have.

The serial driver in 2.6.24.7 works correctly, and the good news is
that 2.6.26-rc2 also works fine.

Chris

Re: pppd and 2.6.25 serial driver

[Andrew Morton]

On Sun, 1 Jun 2008 21:56:21 +0100 Chris Vine <chris@cvine.freeserve.co.uk> wrote:

> Because I have had to resort to using dial-up this weekend, I noticed
> that the serial driver for the 8250/16550 UART in the 2.6.25 kernel does
> not work correctly with ppp-2.4.4. After establishing a dial-up modem
> connection it becomes unresponsive and pppd will exit waiting to
> establish a ppp connection after sending LCP configuration requests.  I
> have tested this with two different dial-up modems and at two different
> dial-up providers, with the 2.6.25.3 and 2.6.25.4 kernels.
> 
> pppd works fine with the 2.6.25 kernel if the serial driver is not used
> (for example if establishing a ppp connection over (in kernel) ATM or
> via an (out of kernel tree) softmodem driver I have.
> 
> The serial driver in 2.6.24.7 works correctly, and the good news is
> that 2.6.26-rc2 also works fine.
> 

Fun.  Presumably that means there's some serial fix which we forgot
to backport.  Or it isn't in 2.6.25.x yet.

Re: pppd and 2.6.25 serial driver

[Alan Cox]

> > The serial driver in 2.6.24.7 works correctly, and the good news is
> > that 2.6.26-rc2 also works fine.
> > 
> 
> Fun.  Presumably that means there's some serial fix which we forgot
> to backport.  Or it isn't in 2.6.25.x yet.

No relevant changes, and the 2.6.26 stuff isn't a trivial backport or
relevant either that I can see. Also it seems to work for everyone else
which makes me suspicious.

Alan

Re: pppd and 2.6.25 serial driver

[Alan Cox]

> Who uses internet dial-up these days?  However, it could be something

Quite a lot of people, especially outside the UK.

> odd about my hardware, which is a laptop using via chipsets, but it
> is also ppp specific, as I can receive faxes with a fax modem using the
> 2.6.25 serial driver.
> 
> Anyway, I have checked with the serial driver in the latest 2.6.26
> (2.6.26-rc5) and that still works fine with ppp.

Good to know.

Re: pppd and 2.6.25 serial driver

[Chris Vine]

On Fri, 6 Jun 2008 11:09:28 +0100
Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:
> No relevant changes, and the 2.6.26 stuff isn't a trivial backport or
> relevant either that I can see. Also it seems to work for everyone
> else which makes me suspicious.

Who uses internet dial-up these days?  However, it could be something
odd about my hardware, which is a laptop using via chipsets, but it
is also ppp specific, as I can receive faxes with a fax modem using the
2.6.25 serial driver.

Anyway, I have checked with the serial driver in the latest 2.6.26
(2.6.26-rc5) and that still works fine with ppp.

Chris