On Thu, Jan 29, 2015 at 11:14:14AM +0000, James Hogan wrote: > Implement KGDB IO operations for MIPS Fast Debug Channel (FDC). This can > be enabled via Kconfig, which also allows the channel number to be > chosen. > > The magic sysrq hack is implemented in the TTY driver, detecting just ^C > for the KGDB channel, and ^O followed by a letter for the FDC console > channel. > > The KGDB operations are reasonably efficient thanks to the flush > callback, with a 4 byte buffer being used in both directions to allow up > to 4 bytes to be encoded per FDC word. Reading of data for KGDB will > discard any data received on other channels, which clearly isn't ideal, > but given that there is a single FIFO shared between channels we can't > do much better. > > Signed-off-by: James Hogan <james.hogan@xxxxxxxxxx> > Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx> > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > Cc: Jiri Slaby <jslaby@xxxxxxx> > Cc: Jason Wessel <jason.wessel@xxxxxxxxxxxxx> > Cc: linux-mips@xxxxxxxxxxxxxx > Cc: kgdb-bugreport@xxxxxxxxxxxxxxxxxxxxx Acked-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
