On Thu, Dec 02, 2010 at 12:52:41AM +0100, Matthias Reichl wrote: > Hi Greg! > > On Wed, Dec 01, 2010 at 02:16:04PM -0800, Greg KH wrote: > > On Wed, Dec 01, 2010 at 05:46:34PM +0100, Matthias Reichl wrote: > > > I've got a Lindy 51237 multi I/O card (2 16C950 URATs up to 921kbit > > > plus one parallel port) with a Oxford OXuPCI952 chip (PCI vendor > > > ID 0x1415, device ID 0x9505). > > > > > > http://www.lindy-international.com/2-port-rs-232-serial-1-port-parallel-card-pci/51237.html > > > http://www.plxtech.com/products/uart/oxupci952 > > > > > > Kernel 2.6.36.1 doesn't contain any device-specific configuration, > > > the "guess code" detects both UARTs at BAR0 and BAR1, > > > but with the wrong baudrate (default of 115200 instead of > > > 921600 needed for this card). > > > > > > The card doesn't report any specific (sub-) vendor/device IDs but > > > the generic Oxford IDs. So adding an entry to the pci_device_id > > > table with a pbn_b0_bt_2_921600 config might break some prior > > > working setups (OXuPCI952 with baud_base=115200). > > > > > > Do you have any policy how to cope with such situations? > > > > Always set the baud rate to a valid one before using the tty port? > > Sorry, I meant baud_base (or base_baud in 8250_pci.c), not baudrate :-( > > Since the baud_base is differing (115200 instead of 921600) > setting a baudrate of X results in an actual baudrate of X*8 for > this card. > > It's no problem for me to do a "setserial ... baud_base=921600" > or pass a module/kernel parameter to circumvent the problem, > but it sure would be nicer if the kernel would have set > the baud_base correctly. > > The problem I'm seeing here is that this card is using a stock > OXuPCI952, which can be equipped with any oscillator, and doesn't > report any vendor-specific PCI IDs that lets it be distinguished > from other stock OXuPCI952 cards - otherwise I've just sent > a "[PATCH] Add support for Lindy 51237" to set baud_base=921600 > for this specific card. > > Personally, all 16C950 (compatible) cards I've bought so far > were capable of a max. 921kbit/sec (and thus had a baud_base of 921600). > So the current default of 115200 doesn't quite match my setup. > If I only need a card capable of 115200 bit/sec I usually buy > a standard 16550 card (not a 16C950). > > So, my question is: would you include a patch in the kernel > to change the default baud_base from 115200 to 921600 for > the OXuPCI952 chip (1415:9505)? As it sounds like this might break existing setups, I'd probably defer to not taking such a patch. sorry, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
