On Fri, 2007-10-12 at 12:31 +1000, David Gibson wrote: > On Thu, Oct 11, 2007 at 01:31:53PM -0500, Josh Boyer wrote: > > On Thu, 2007-10-11 at 21:26 +0400, Valentine Barshak wrote: > > > Josh Boyer wrote: > > > > On Thu, 2007-10-11 at 17:50 +0200, Arnd Bergmann wrote: > > > >> On Thursday 11 October 2007, Valentine Barshak wrote: > > > >>> Currently find_legacy_serial_ports() can find no serial ports on the > > > >>> OPB. > > > >>> Thus no legacy boot console can be initialized. Just the early udbg > > > >>> console > > > >>> works, which is initialized with udbg_init_44x_as1() on the UART's > > > >>> physical > > > >>> address specified in kernel config. This happens because we look for > > > >>> ns16750 > > > >>> and higher serial devices only and expect opb node to have a device > > > >>> type > > > >>> property. This patch makes it look for ns16550 compatible devices and > > > >>> use > > > >>> of_device_is_compatible() for opb instead of checking device type. > > > >>> Lack of legacy serial ports found causes problems for KGDB over > > > >>> serial. > > > >>> > > > >>> Signed-off-by: Valentine Barshak <[EMAIL PROTECTED]> > > > >> The patch would make sense if we were only dealing with flattened > > > >> device > > > >> tree systems at this point. Unfortunately, IBM is shipping hardware > > > >> that > > > >> encodes the serial port in exactly the way that > > > >> find_legacy_serial_ports > > > >> is looking for (parent->type == "opb", compatible = "ns16750" "ns16550" > > > >> "ns16450" i8250"). > > > >> > > > >> Changing the search for ns16750 to ns16550 should be fine, but > > > >> unnecessary > > > >> because AFAIK, all OPB serial imlpementations are actually ns16750 and > > > >> should have that in the device tree as well. > > > >> > > > >> For the device type of the bus, please check for both compatible and > > > >> type, so that it still works on machines that are missing the > > > >> compatible > > > >> property. > > > > > > > > Wait, no. We already had this discussion months ago when David was > > > > working on the original Ebony port. It was declared that legacy_serial > > > > is not how serial should be done on 4xx and the serial_of driver was > > > > supposed to be used instead. > > > > > > > > Have we changed our stance on that? If not, then perhaps KGDB should be > > > > fixed to work with serial_of. > > > > > > Actually I don't see any reason not to use legacy_serial stuff for early > > > console. We could split the kernel configured very early debug output, > > > which uses PPC_EARLY_DEBUG_44x_PHYSLOW/PHYSHIGH (since it's really > > > dangerous) and early console things by using legacy serial. We could use > > > early boot console without PPC_EARLY_DEBUG_44x. > > > > That was exactly my thinking when this first came up. I'd like to hear > > David's opinion on it. > > Yeah, I think I misinterpreted BenH way back when. This looks ok, and > means serial will be initialized earlier than of_serial, which would > be nice.
Great. It seems Paul pulled it into his tree already as well, which suits me just fine. josh _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
