4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Nicholas Piggin <npiggin@xxxxxxxxx>
commit c1d2a31397ec51f0370f6bd17b19b39152c263cb upstream.
Similarly to opal_event_shutdown, opal_nvram_write can be called in
the crash path with irqs disabled. Special case the delay to avoid
sleeping in invalid context.
Fixes: 3b8070335f75 ("powerpc/powernv: Fix OPAL NVRAM driver OPAL_BUSY loops")
Cc: stable@xxxxxxxxxxxxxxx # v3.2
Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/platforms/powernv/opal-nvram.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
--- a/arch/powerpc/platforms/powernv/opal-nvram.c
+++ b/arch/powerpc/platforms/powernv/opal-nvram.c
@@ -44,6 +44,10 @@ static ssize_t opal_nvram_read(char *buf
return count;
}
+/*
+ * This can be called in the panic path with interrupts off, so use
+ * mdelay in that case.
+ */
static ssize_t opal_nvram_write(char *buf, size_t count, loff_t *index)
{
s64 rc = OPAL_BUSY;
@@ -58,10 +62,16 @@ static ssize_t opal_nvram_write(char *bu
while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
rc = opal_write_nvram(__pa(buf), count, off);
if (rc == OPAL_BUSY_EVENT) {
- msleep(OPAL_BUSY_DELAY_MS);
+ if (in_interrupt() || irqs_disabled())
+ mdelay(OPAL_BUSY_DELAY_MS);
+ else
+ msleep(OPAL_BUSY_DELAY_MS);
opal_poll_events(NULL);
} else if (rc == OPAL_BUSY) {
- msleep(OPAL_BUSY_DELAY_MS);
+ if (in_interrupt() || irqs_disabled())
+ mdelay(OPAL_BUSY_DELAY_MS);
+ else
+ msleep(OPAL_BUSY_DELAY_MS);
}
}
