[PATCH] Fix staging:iio:ring_sw: Fix incorrect test on successfulread of last value, causes infinite loop

From: Jonathan Cameron
Date: Tue Mar 30 2010 - 12:42:38 EST



Signed-off-by: Jonathan Cameron <jic23@xxxxxxxxx>
---

This is a bad one. The test means that almost no reads of the last
value ever succeed! Result is an infinite loop.

Another one for the 'oops' category.

Patch is post the spin lock fix:
[PATCH] Staging: IIO: Fix uses of spinlocks prior to init in ring implementations


drivers/staging/iio/ring_sw.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/staging/iio/ring_sw.c b/drivers/staging/iio/ring_sw.c
index 7dff2bf..5abba8c 100644
--- a/drivers/staging/iio/ring_sw.c
+++ b/drivers/staging/iio/ring_sw.c
@@ -296,7 +296,7 @@ again:
return -EAGAIN;
memcpy(data, last_written_p_copy, ring->buf.bpd);

- if (unlikely(ring->last_written_p >= last_written_p_copy))
+ if (unlikely(ring->last_written_p != last_written_p_copy))
goto again;

iio_unmark_sw_rb_in_use(&ring->buf);
--
1.6.4.4

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