ARM: 7116/1: debug: provide dummy default option for DEBUG_LL UART choice

Defaulting to DEBUG_ICEDCC will cause systems to hang during boot unless
a hardware debugger is listening to the debug comms. channel.

This patch adds a dummy UART option as the default DEBUG_LL choice which
requires the platform to do the right thing.

Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Tested-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 10 insertions, 2 deletions

diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
index 91a826308d56..b3dc1fa30848 100644
--- a/arch/arm/Kconfig.debug
+++ b/arch/arm/Kconfig.debug
@@ -81,6 +81,14 @@ choice
         prompt "Kernel low-level debugging port"
         depends on DEBUG_LL
 
+        config DEBUG_LL_UART_NONE
+                bool "No low-level debugging UART"
+                help
+                  Say Y here if your platform doesn't provide a UART option
+                  below. This relies on your platform choosing the right UART
+                  definition internally in order for low-level debugging to
+                  work.
+
         config DEBUG_ICEDCC
                 bool "Kernel low-level debugging via EmbeddedICE DCC channel"
                 help
@@ -89,8 +97,8 @@ choice
                   co-processor 14. This is known to work on the ARM9 style ICE
                   channel and on the XScale with the PEEDI.
 
-                  It does include a timeout to ensure that the system does not
-                  totally freeze when there is nothing connected to read.
+                  Note that the system will appear to hang during boot if there
+                  is nothing connected to read from the DCC.
 
         config DEBUG_FOOTBRIDGE_COM1
                 bool "Kernel low-level debugging messages via footbridge 8250 at PCI COM1"