[PATCH 4.14 051/164] powerpc/powernv: Handle unknown OPAL errors in opal_nvram_write()

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Nicholas Piggin <npiggin@gmail.com>

commit 741de617661794246f84a21a02fc5e327bffc9ad upstream.

opal_nvram_write currently just assumes success if it encounters an
error other than OPAL_BUSY or OPAL_BUSY_EVENT. Have it return -EIO
on other errors instead.

Fixes: 628daa8d5abf ("powerpc/powernv: Add RTC and NVRAM support plus RTAS fallbacks")
Cc: stable@vger.kernel.org # v3.2+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Acked-by: Stewart Smith <stewart@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/powerpc/platforms/powernv/opal-nvram.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/arch/powerpc/platforms/powernv/opal-nvram.c
+++ b/arch/powerpc/platforms/powernv/opal-nvram.c
@@ -59,6 +59,10 @@ static ssize_t opal_nvram_write(char *bu
 		if (rc == OPAL_BUSY_EVENT)
 			opal_poll_events(NULL);
 	}
+
+	if (rc)
+		return -EIO;
+
 	*index += count;
 	return count;
 }