* [PATCH 2/5] drivers/media/video/uvc: Use DIV_ROUND_CLOSEST
@ 2009-08-01 19:49 ` Julia Lawall
0 siblings, 0 replies; 6+ messages in thread
From: Julia Lawall @ 2009-08-01 19:49 UTC (permalink / raw)
To: laurent.pinchart, linux-media, linux-uvc-devel, linux-kernel,
kernel-janitors
From: Julia Lawall <julia@diku.dk>
The kernel.h macro DIV_ROUND_CLOSEST performs the computation (x + d/2)/d
but is perhaps more readable.
The semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@haskernel@
@@
#include <linux/kernel.h>
@depends on haskernel@
expression x,__divisor;
@@
- (((x) + ((__divisor) / 2)) / (__divisor))
+ DIV_ROUND_CLOSEST(x,__divisor)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
---
drivers/media/video/uvc/uvc_v4l2.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/drivers/media/video/uvc/uvc_v4l2.c b/drivers/media/video/uvc/uvc_v4l2.c
index 87cb9cc..6edaaf6 100644
--- a/drivers/media/video/uvc/uvc_v4l2.c
+++ b/drivers/media/video/uvc/uvc_v4l2.c
@@ -95,7 +95,7 @@ static __u32 uvc_try_frame_interval(struct uvc_frame *frame, __u32 interval)
const __u32 max = frame->dwFrameInterval[1];
const __u32 step = frame->dwFrameInterval[2];
- interval = min + (interval - min + step/2) / step * step;
+ interval = min + DIV_ROUND_CLOSEST(interval-min, step) * step;
if (interval > max)
interval = max;
}
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 2/5] drivers/media/video/uvc: Use DIV_ROUND_CLOSEST
@ 2009-08-01 19:49 ` Julia Lawall
0 siblings, 0 replies; 6+ messages in thread
From: Julia Lawall @ 2009-08-01 19:49 UTC (permalink / raw)
To: laurent.pinchart, linux-media, linux-uvc-devel, linux-kernel,
kernel-janitors
From: Julia Lawall <julia@diku.dk>
The kernel.h macro DIV_ROUND_CLOSEST performs the computation (x + d/2)/d
but is perhaps more readable.
The semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@haskernel@
@@
#include <linux/kernel.h>
@depends on haskernel@
expression x,__divisor;
@@
- (((x) + ((__divisor) / 2)) / (__divisor))
+ DIV_ROUND_CLOSEST(x,__divisor)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
---
drivers/media/video/uvc/uvc_v4l2.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/drivers/media/video/uvc/uvc_v4l2.c b/drivers/media/video/uvc/uvc_v4l2.c
index 87cb9cc..6edaaf6 100644
--- a/drivers/media/video/uvc/uvc_v4l2.c
+++ b/drivers/media/video/uvc/uvc_v4l2.c
@@ -95,7 +95,7 @@ static __u32 uvc_try_frame_interval(struct uvc_frame *frame, __u32 interval)
const __u32 max = frame->dwFrameInterval[1];
const __u32 step = frame->dwFrameInterval[2];
- interval = min + (interval - min + step/2) / step * step;
+ interval = min + DIV_ROUND_CLOSEST(interval-min, step) * step;
if (interval > max)
interval = max;
}
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH 2/5] drivers/media/video/uvc: Use DIV_ROUND_CLOSEST
2009-08-01 19:49 ` Julia Lawall
@ 2009-08-01 20:23 ` Laurent Pinchart
-1 siblings, 0 replies; 6+ messages in thread
From: Laurent Pinchart @ 2009-08-01 20:23 UTC (permalink / raw)
To: Julia Lawall; +Cc: linux-media, linux-uvc-devel, linux-kernel, kernel-janitors
On Saturday 01 August 2009 21:49:04 Julia Lawall wrote:
> From: Julia Lawall <julia@diku.dk>
>
> The kernel.h macro DIV_ROUND_CLOSEST performs the computation (x + d/2)/d
> but is perhaps more readable.
>
> The semantic patch that makes this change is as follows:
> (http://www.emn.fr/x-info/coccinelle/)
>
> // <smpl>
> @haskernel@
> @@
>
> #include <linux/kernel.h>
>
> @depends on haskernel@
> expression x,__divisor;
> @@
>
> - (((x) + ((__divisor) / 2)) / (__divisor))
> + DIV_ROUND_CLOSEST(x,__divisor)
> // </smpl>
>
> Signed-off-by: Julia Lawall <julia@diku.dk>
>
> ---
> drivers/media/video/uvc/uvc_v4l2.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/media/video/uvc/uvc_v4l2.c
> b/drivers/media/video/uvc/uvc_v4l2.c index 87cb9cc..6edaaf6 100644
> --- a/drivers/media/video/uvc/uvc_v4l2.c
> +++ b/drivers/media/video/uvc/uvc_v4l2.c
> @@ -95,7 +95,7 @@ static __u32 uvc_try_frame_interval(struct uvc_frame
> *frame, __u32 interval) const __u32 max = frame->dwFrameInterval[1];
> const __u32 step = frame->dwFrameInterval[2];
>
> - interval = min + (interval - min + step/2) / step * step;
> + interval = min + DIV_ROUND_CLOSEST(interval-min, step) * step;
> if (interval > max)
> interval = max;
> }
The purpose of the above code is to clamp the interval value to the [min, max]
range at round it to the closest multiple of step. Other drivers might need
similar code. Do you think it might be useful to introduce a clamp_step macro
for this ?
If not,
Acked-by: Laurent Pinchart <laurent.pinchart@skynet.be>
Regards,
Laurent Pinchart
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 2/5] drivers/media/video/uvc: Use DIV_ROUND_CLOSEST
@ 2009-08-01 20:23 ` Laurent Pinchart
0 siblings, 0 replies; 6+ messages in thread
From: Laurent Pinchart @ 2009-08-01 20:23 UTC (permalink / raw)
To: Julia Lawall; +Cc: linux-media, linux-uvc-devel, linux-kernel, kernel-janitors
On Saturday 01 August 2009 21:49:04 Julia Lawall wrote:
> From: Julia Lawall <julia@diku.dk>
>
> The kernel.h macro DIV_ROUND_CLOSEST performs the computation (x + d/2)/d
> but is perhaps more readable.
>
> The semantic patch that makes this change is as follows:
> (http://www.emn.fr/x-info/coccinelle/)
>
> // <smpl>
> @haskernel@
> @@
>
> #include <linux/kernel.h>
>
> @depends on haskernel@
> expression x,__divisor;
> @@
>
> - (((x) + ((__divisor) / 2)) / (__divisor))
> + DIV_ROUND_CLOSEST(x,__divisor)
> // </smpl>
>
> Signed-off-by: Julia Lawall <julia@diku.dk>
>
> ---
> drivers/media/video/uvc/uvc_v4l2.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/media/video/uvc/uvc_v4l2.c
> b/drivers/media/video/uvc/uvc_v4l2.c index 87cb9cc..6edaaf6 100644
> --- a/drivers/media/video/uvc/uvc_v4l2.c
> +++ b/drivers/media/video/uvc/uvc_v4l2.c
> @@ -95,7 +95,7 @@ static __u32 uvc_try_frame_interval(struct uvc_frame
> *frame, __u32 interval) const __u32 max = frame->dwFrameInterval[1];
> const __u32 step = frame->dwFrameInterval[2];
>
> - interval = min + (interval - min + step/2) / step * step;
> + interval = min + DIV_ROUND_CLOSEST(interval-min, step) * step;
> if (interval > max)
> interval = max;
> }
The purpose of the above code is to clamp the interval value to the [min, max]
range at round it to the closest multiple of step. Other drivers might need
similar code. Do you think it might be useful to introduce a clamp_step macro
for this ?
If not,
Acked-by: Laurent Pinchart <laurent.pinchart@skynet.be>
Regards,
Laurent Pinchart
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 2/5] drivers/media/video/uvc: Use DIV_ROUND_CLOSEST
2009-08-01 20:23 ` Laurent Pinchart
@ 2009-08-02 6:20 ` Julia Lawall
-1 siblings, 0 replies; 6+ messages in thread
From: Julia Lawall @ 2009-08-02 6:20 UTC (permalink / raw)
To: Laurent Pinchart
Cc: linux-media, linux-uvc-devel, linux-kernel, kernel-janitors
On Sat, 1 Aug 2009, Laurent Pinchart wrote:
> On Saturday 01 August 2009 21:49:04 Julia Lawall wrote:
> > From: Julia Lawall <julia@diku.dk>
> >
> > The kernel.h macro DIV_ROUND_CLOSEST performs the computation (x + d/2)/d
> > but is perhaps more readable.
> >
> > The semantic patch that makes this change is as follows:
> > (http://www.emn.fr/x-info/coccinelle/)
> >
> > // <smpl>
> > @haskernel@
> > @@
> >
> > #include <linux/kernel.h>
> >
> > @depends on haskernel@
> > expression x,__divisor;
> > @@
> >
> > - (((x) + ((__divisor) / 2)) / (__divisor))
> > + DIV_ROUND_CLOSEST(x,__divisor)
> > // </smpl>
> >
> > Signed-off-by: Julia Lawall <julia@diku.dk>
> >
> > ---
> > drivers/media/video/uvc/uvc_v4l2.c | 2 +-
> > 1 files changed, 1 insertions(+), 1 deletions(-)
> >
> > diff --git a/drivers/media/video/uvc/uvc_v4l2.c
> > b/drivers/media/video/uvc/uvc_v4l2.c index 87cb9cc..6edaaf6 100644
> > --- a/drivers/media/video/uvc/uvc_v4l2.c
> > +++ b/drivers/media/video/uvc/uvc_v4l2.c
> > @@ -95,7 +95,7 @@ static __u32 uvc_try_frame_interval(struct uvc_frame
> > *frame, __u32 interval) const __u32 max = frame->dwFrameInterval[1];
> > const __u32 step = frame->dwFrameInterval[2];
> >
> > - interval = min + (interval - min + step/2) / step * step;
> > + interval = min + DIV_ROUND_CLOSEST(interval-min, step) * step;
> > if (interval > max)
> > interval = max;
> > }
>
> The purpose of the above code is to clamp the interval value to the [min, max]
> range at round it to the closest multiple of step. Other drivers might need
> similar code. Do you think it might be useful to introduce a clamp_step macro
> for this ?
I tried searching for the following:
@@
expression interval, min, max, step, E;
@@
* interval = min + (interval - min + step/2) / step * step;
... when != interval = E
* if (interval > max)
{ ...
interval = max;
... }
@@
expression interval, min, max, step, E;
@@
* interval = min + DIV_ROUND_CLOSEST(interval-min, step) * step;
... when != interval = E
* if (interval > max) { ...
interval = max;
... }
and the only occurrence I found was the code above. Perhaps there is some
other way in which the pattern would appear?
julia
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 2/5] drivers/media/video/uvc: Use DIV_ROUND_CLOSEST
@ 2009-08-02 6:20 ` Julia Lawall
0 siblings, 0 replies; 6+ messages in thread
From: Julia Lawall @ 2009-08-02 6:20 UTC (permalink / raw)
To: Laurent Pinchart
Cc: linux-media, linux-uvc-devel, linux-kernel, kernel-janitors
On Sat, 1 Aug 2009, Laurent Pinchart wrote:
> On Saturday 01 August 2009 21:49:04 Julia Lawall wrote:
> > From: Julia Lawall <julia@diku.dk>
> >
> > The kernel.h macro DIV_ROUND_CLOSEST performs the computation (x + d/2)/d
> > but is perhaps more readable.
> >
> > The semantic patch that makes this change is as follows:
> > (http://www.emn.fr/x-info/coccinelle/)
> >
> > // <smpl>
> > @haskernel@
> > @@
> >
> > #include <linux/kernel.h>
> >
> > @depends on haskernel@
> > expression x,__divisor;
> > @@
> >
> > - (((x) + ((__divisor) / 2)) / (__divisor))
> > + DIV_ROUND_CLOSEST(x,__divisor)
> > // </smpl>
> >
> > Signed-off-by: Julia Lawall <julia@diku.dk>
> >
> > ---
> > drivers/media/video/uvc/uvc_v4l2.c | 2 +-
> > 1 files changed, 1 insertions(+), 1 deletions(-)
> >
> > diff --git a/drivers/media/video/uvc/uvc_v4l2.c
> > b/drivers/media/video/uvc/uvc_v4l2.c index 87cb9cc..6edaaf6 100644
> > --- a/drivers/media/video/uvc/uvc_v4l2.c
> > +++ b/drivers/media/video/uvc/uvc_v4l2.c
> > @@ -95,7 +95,7 @@ static __u32 uvc_try_frame_interval(struct uvc_frame
> > *frame, __u32 interval) const __u32 max = frame->dwFrameInterval[1];
> > const __u32 step = frame->dwFrameInterval[2];
> >
> > - interval = min + (interval - min + step/2) / step * step;
> > + interval = min + DIV_ROUND_CLOSEST(interval-min, step) * step;
> > if (interval > max)
> > interval = max;
> > }
>
> The purpose of the above code is to clamp the interval value to the [min, max]
> range at round it to the closest multiple of step. Other drivers might need
> similar code. Do you think it might be useful to introduce a clamp_step macro
> for this ?
I tried searching for the following:
@@
expression interval, min, max, step, E;
@@
* interval = min + (interval - min + step/2) / step * step;
... when != interval = E
* if (interval > max)
{ ...
interval = max;
... }
@@
expression interval, min, max, step, E;
@@
* interval = min + DIV_ROUND_CLOSEST(interval-min, step) * step;
... when != interval = E
* if (interval > max) { ...
interval = max;
... }
and the only occurrence I found was the code above. Perhaps there is some
other way in which the pattern would appear?
julia
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2009-08-02 6:23 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2009-08-01 19:49 [PATCH 2/5] drivers/media/video/uvc: Use DIV_ROUND_CLOSEST Julia Lawall
2009-08-01 19:49 ` Julia Lawall
2009-08-01 20:23 ` Laurent Pinchart
2009-08-01 20:23 ` Laurent Pinchart
2009-08-02 6:20 ` Julia Lawall
2009-08-02 6:20 ` Julia Lawall
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