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authorNicholas Piggin <npiggin@gmail.com>2018-05-15 01:59:47 +1000
committerMichael Ellerman <mpe@ellerman.id.au>2018-05-18 00:23:07 +1000
commitc1d2a31397ec51f0370f6bd17b19b39152c263cb (patch)
tree9962f0d0a9da497be14ef59ed624a5a15befc85f
parent497a0790e2c604366b9e35dcb41310319e9bca13 (diff)
downloadlinux-berlin-c1d2a31397ec51f0370f6bd17b19b39152c263cb.tar.gz
powerpc/powernv: Fix NVRAM sleep in invalid context when crashing
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@vger.kernel.org # v3.2 Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
-rw-r--r--arch/powerpc/platforms/powernv/opal-nvram.c14
1 files changed, 12 insertions, 2 deletions
diff --git a/arch/powerpc/platforms/powernv/opal-nvram.c b/arch/powerpc/platforms/powernv/opal-nvram.c
index 1bceb95f422d0f..5584247f502929 100644
--- 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, size_t count, loff_t *index)
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 *buf, size_t count, loff_t *index)
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);
}
}