* [PATCH] vme: 8-bit status/id takes 256 values, not 255
@ 2015-10-10 22:00 Dmitry Kalinkin
2015-10-18 13:30 ` Martyn Welch
0 siblings, 1 reply; 4+ messages in thread
From: Dmitry Kalinkin @ 2015-10-10 22:00 UTC (permalink / raw)
To: Greg Kroah-Hartman, Martyn Welch, Manohar Vanga
Cc: devel, linux-kernel, Dmitry Kalinkin
Fixes an off by one array size.
Signed-off-by: Dmitry Kalinkin <dmitry.kalinkin@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
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] vme: 8-bit status/id takes 256 values, not 255
2015-10-10 22:00 [PATCH] vme: 8-bit status/id takes 256 values, not 255 Dmitry Kalinkin
@ 2015-10-18 13:30 ` Martyn Welch
2015-10-18 17:07 ` Dmitry Kalinkin
0 siblings, 1 reply; 4+ messages in thread
From: Martyn Welch @ 2015-10-18 13:30 UTC (permalink / raw)
To: Dmitry Kalinkin; +Cc: Greg Kroah-Hartman, Manohar Vanga, devel, linux-kernel
On 10 October 2015 at 23:00, Dmitry Kalinkin <dmitry.kalinkin@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?
Martyn
> Signed-off-by: Dmitry Kalinkin <dmitry.kalinkin@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
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] vme: 8-bit status/id takes 256 values, not 255
2015-10-18 13:30 ` Martyn Welch
@ 2015-10-18 17:07 ` Dmitry Kalinkin
2015-10-18 18:22 ` Martyn Welch
0 siblings, 1 reply; 4+ messages in thread
From: Dmitry Kalinkin @ 2015-10-18 17:07 UTC (permalink / raw)
To: Martyn Welch; +Cc: Greg Kroah-Hartman, Manohar Vanga, devel, LKML
On Sun, Oct 18, 2015 at 9:30 AM, Martyn Welch <martyn@welchs.me.uk> wrote:
> On 10 October 2015 at 23:00, Dmitry Kalinkin <dmitry.kalinkin@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.
Dmitri
>
> Martyn
>
>> Signed-off-by: Dmitry Kalinkin <dmitry.kalinkin@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
>>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] vme: 8-bit status/id takes 256 values, not 255
2015-10-18 17:07 ` Dmitry Kalinkin
@ 2015-10-18 18:22 ` Martyn Welch
0 siblings, 0 replies; 4+ messages in thread
From: Martyn Welch @ 2015-10-18 18:22 UTC (permalink / raw)
To: Dmitry Kalinkin; +Cc: Greg Kroah-Hartman, Manohar Vanga, devel, LKML
On 18/10/15 18:07, Dmitry Kalinkin wrote:
> On Sun, Oct 18, 2015 at 9:30 AM, Martyn Welch <martyn@welchs.me.uk> wrote:
>> On 10 October 2015 at 23:00, Dmitry Kalinkin <dmitry.kalinkin@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 <martyn@welchs.me.uk>
> Dmitri
>
>> Martyn
>>
>>> Signed-off-by: Dmitry Kalinkin <dmitry.kalinkin@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
>>>
^ permalink raw reply [flat|nested] 4+ messages in thread
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2015-10-10 22:00 [PATCH] vme: 8-bit status/id takes 256 values, not 255 Dmitry Kalinkin
2015-10-18 13:30 ` Martyn Welch
2015-10-18 17:07 ` Dmitry Kalinkin
2015-10-18 18:22 ` Martyn Welch
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