On 18/10/15 18:07, Dmitry Kalinkin wrote:
On Sun, Oct 18, 2015 at 9:30 AM, Martyn Welch <mar...@welchs.me.uk> wrote:
On 10 October 2015 at 23:00, Dmitry Kalinkin <dmitry.kalin...@gmail.com> wrote:
Fixes an off by one array size.
The Status/ID is an 8-bit value (OK, the standard states it can be a
8, 16 or 32-bit value, however both of the chipsets we support at this
point in time support an 8-bit value), why do we need a 256th entry in
the array?
Hi Martyn,
8 bit signal spans 256 values from 8'b0000_0000 to 8'b1111_1111.
In order to serve that we need a C array of size 256.
callback[255]; in the original code means that array has 255 elements
with indices from 0 to 254, there would be no way to register callback
for a valid Status/ID value of 255 (aka 8'b1111_1111). For that we
need a 256th element.
Err, yep. (Curses self for being so stupid.)
Signed-off-by: Martyn Welch <mar...@welchs.me.uk>
Dmitri
Martyn
Signed-off-by: Dmitry Kalinkin <dmitry.kalin...@gmail.com>
---
drivers/vme/vme_bridge.h | 4 +++-
include/linux/vme.h | 3 +++
2 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/vme/vme_bridge.h b/drivers/vme/vme_bridge.h
index 397578a..b59cbee 100644
--- a/drivers/vme/vme_bridge.h
+++ b/drivers/vme/vme_bridge.h
@@ -1,6 +1,8 @@
#ifndef _VME_BRIDGE_H_
#define _VME_BRIDGE_H_
+#include <linux/vme.h>
+
#define VME_CRCSR_BUF_SIZE (508*1024)
/*
* Resource structures
@@ -91,7 +93,7 @@ struct vme_callback {
struct vme_irq {
int count;
- struct vme_callback callback[255];
+ struct vme_callback callback[VME_NUM_STATUSID];
};
/* Allow 16 characters for name (including null character) */
diff --git a/include/linux/vme.h b/include/linux/vme.h
index c013135..71e4a6d 100644
--- a/include/linux/vme.h
+++ b/include/linux/vme.h
@@ -81,6 +81,9 @@ struct vme_resource {
extern struct bus_type vme_bus_type;
+/* Number of VME interrupt vectors */
+#define VME_NUM_STATUSID 256
+
/* VME_MAX_BRIDGES comes from the type of vme_bus_numbers */
#define VME_MAX_BRIDGES (sizeof(unsigned int)*8)
#define VME_MAX_SLOTS 32
--
1.8.3.1
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