On Mon, Feb 28, 2005 at 11:40:22PM -0800, David Lawyer wrote: > On Tue, Mar 01, 2005 at 11:55:42AM +0900, Horms wrote: > > On Fri, Feb 25, 2005 at 12:07:20AM -0800, David Lawyer wrote: > > > I fixed the problem by setting the parallel port in the BIOS from ECP to > > > SPP. Then the driver does software handshaking and my old printer works > > > OK. So this is a problem with documentation. I just emailed the > > > authors of the kernel docs on the parallel port and told them about this > > > fix. So you could close this bug if you want to, although it would be > > > nice if somehow the software configured it all. > > > > Hi David, > > > > are you suggesting that there should be a kernel option > > to restrict the modes that the parallel port driver will > > operate in - so that if you have older hardware it will only > > use modes supported by the other end. Or are you suggesting > > that the driver should autodetect this somehow. My knowledge > > of the relevant specs are weak (non-existant), but the latter > > sounds like it might not be possible. > > I think the latter may be possible if one has a modern (not over 20 > years old) parrallel port on their PC (like I do). There's a spec for > negotiation between the two ports over the parallel cable. In my case, > there would be no response from my printer and it would then be assumed > by my PC that the printer port doesn't meet IEEE 1284 specs and thus use > the old Centronics protocol known as SPP. But I don't know how the port > tells that to Linux. The old protocol requires driver handshaking for > every byte sent. > > I think that the BIOS allows setting SPP for cases where the software > doesn't know about ECP. Since Linux knows about ECP and since ECP can > fallback to SPP mode, it should have worked in ECP mode. So I now think > it's a bug and needs to be fixed even though I found a work around to > get my printer printing.
Sure, that makes sense to me. > > In any case, have you considered reporting this to LKML and > > the maintainers? > How do I do this? I would email the [email protected] and CC the listed in the MAINTAINERS file. Actually, I see there is a list for parallel port support, so you might be better off to mail that + CC the maintainers. In any case, here is the info. PARALLEL PORT SUPPORT P: Phil Blundell M: [EMAIL PROTECTED] P: Tim Waugh M: [EMAIL PROTECTED] P: David Campbell M: [EMAIL PROTECTED] P: Andrea Arcangeli M: [EMAIL PROTECTED] L: [EMAIL PROTECTED] W: http://people.redhat.com/twaugh/parport/ S: Maintained -- Horms -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
