powerpc/powernv: Properly drop characters if console is closed

If the firmware returns an error such as "closed" (or hardware
error), we should drop characters.

Currently we only do that when a firmware compatible with OPAL v2
APIs is detected, in the code that calls opal_console_write_buffer_space(),
which didn't exist with OPAL v1 (or didn't work).

However, when enabling early debug consoles, the flag indicating
that v2 is supported isn't set yet, causing us, in case of errors
or closed console, to spin forever.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index ade4463226c612fd338b5cbaed1cb941d14881a9..12d9846aa87e4991c99b38be6d9e0caba466ccf6 100644 (file)
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -144,6 +144,13 @@ int opal_put_chars(uint32_t vtermno, const char *data, int total_len)
                                rc == OPAL_BUSY_EVENT || rc == OPAL_SUCCESS)) {
                len = total_len;
                rc = opal_console_write(vtermno, &len, data);
+
+               /* Closed or other error drop */
+               if (rc != OPAL_SUCCESS && rc != OPAL_BUSY &&
+                   rc != OPAL_BUSY_EVENT) {
+                       written = total_len;
+                       break;
+               }
                if (rc == OPAL_SUCCESS) {
                        total_len -= len;
                        data += len;