powerpc/pseries/hvconsole: Fix dropped console output

[ upstream commit 51d33021425e1f905beb4208823146f2fb6517da ]

Return -EAGAIN when we get H_BUSY back from the hypervisor. This
makes the hvc console driver retry, avoiding dropped printks.

Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: <stable@kernel.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

diff --git a/arch/powerpc/platforms/pseries/hvconsole.c b/arch/powerpc/platforms/pseries/hvconsole.c
index 3f6a89b09816ee667b323214e3f8efbb949efad7..041e87ca189314cebd032320cf7df53c6fcf2888 100644 (file)
--- a/arch/powerpc/platforms/pseries/hvconsole.c
+++ b/arch/powerpc/platforms/pseries/hvconsole.c
@@ -73,7 +73,7 @@ int hvc_put_chars(uint32_t vtermno, const char *buf, int count)
        if (ret == H_SUCCESS)
                return count;
        if (ret == H_BUSY)
-               return 0;
+               return -EAGAIN;
        return -EIO;
 }