powerpc/hvc_udbg: Don't crash when udbg_putc is NULL
authorBenjamin Herrenschmidt <benh@kernel.crashing.org>
Wed, 14 Mar 2012 07:37:04 +0000 (18:37 +1100)
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>
Thu, 15 Mar 2012 22:28:15 +0000 (09:28 +1100)
commit7d3d897a4697e4ff746e5e82f116b2346ed28150
tree740b5a83f9d354edf255f44a6072a47ec1ff7ba0
parentba7a4822b48fbc7afd6b567c18e316a03f46684d
powerpc/hvc_udbg: Don't crash when udbg_putc is NULL

Also while at it, add some help text indicating why you shouldn't
enable that driver under normal circumstances

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
drivers/tty/hvc/Kconfig
drivers/tty/hvc/hvc_udbg.c