powerpc/powernv: Handle unknown OPAL errors in opal_nvram_write()

BugLink: http://bugs.launchpad.net/bugs/1767927
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>
(cherry-picked from 741de617661794246f84a21a02fc5e327bffc9ad)
Signed-off-by: Gustavo Walbon <gwalbon@linux.vnet.ibm.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/arch/powerpc/platforms/powernv/opal-nvram.c b/arch/powerpc/platforms/powernv/opal-nvram.c
index 9db4398ded5de1f6c8e9a672a51008df1fbc85d7..ba2ff06a2c98b9315e99f2758cedd81903208a85 100644 (file)
--- 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 *buf, size_t count, loff_t *index)
                if (rc == OPAL_BUSY_EVENT)
                        opal_poll_events(NULL);
        }
+
+       if (rc)
+               return -EIO;
+
        *index += count;
        return count;
 }