powerpc/gamecube/wii: Fix off-by-one error in ugecon/usbgecko_udbg

The retry logic in ug_putc() is broken.

If the TX fifo is not ready and the counter runs out it will have a
value of -1 and no transfer should be attempted. Also, a counter
with a value of 0 means that the TX fifo got ready in the last try
and the transfer should be attempted.

Reported-by: "Juha Leppanen" <juha_motorsportcom@luukku.com>
Signed-off-by: "Juha Leppanen" <juha_motorsportcom@luukku.com>
Signed-off-by: Albert Herranz <albert_herranz@yahoo.es>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

2 files changed, 2 insertions, 2 deletions

diff --git a/arch/powerpc/boot/ugecon.c b/arch/powerpc/boot/ugecon.c
index 50609ea6ddf8..8f2a6b311534 100644
--- a/arch/powerpc/boot/ugecon.c
+++ b/arch/powerpc/boot/ugecon.c
@@ -86,7 +86,7 @@ static void ug_putc(char ch)
 
         while (!ug_is_txfifo_ready() && count--)
                 barrier();
-        if (count)
+        if (count >= 0)
                 ug_raw_putc(ch);
 }
 
diff --git a/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c b/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c
index edc956cc8b13..20a8ed91962e 100644
--- a/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c
+++ b/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c
@@ -120,7 +120,7 @@ static void ug_putc(char ch)
 
         while (!ug_is_txfifo_ready() && count--)
                 barrier();
-        if (count)
+        if (count >= 0)
                 ug_raw_putc(ch);
 }