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* [PATCH] staging: nvec: Replace udelay by usleep_range
@ 2017-03-07 12:52 Sreya Mittal
  2017-03-07 15:52 ` [Outreachy kernel] " Julia Lawall
  0 siblings, 1 reply; 6+ messages in thread
From: Sreya Mittal @ 2017-03-07 12:52 UTC (permalink / raw)
  To: outreachy-kernel; +Cc: Sreya Mittal, Marc Dietrich, Greg Kroah-Hartman

Replace udelay by usleep_range.
Fixes the checkpatch issue:
usleep_range is preferred over udelay

In Documentation/timers/timers-howto.txt,
it is mentioned that udelay should be used
for a few microseconds(less than 10), and
usleep_range should be preferred for 10
microseconds to 20 milliseconds.

Signed-off-by: Sreya Mittal <sreyamittal5@gmail.com>
---
 drivers/staging/nvec/nvec.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/nvec/nvec.c b/drivers/staging/nvec/nvec.c
index c1feccf..5fab241 100644
--- a/drivers/staging/nvec/nvec.c
+++ b/drivers/staging/nvec/nvec.c
@@ -631,7 +631,7 @@ static irqreturn_t nvec_interrupt(int irq, void *dev)
 		break;
 	case 2:		/* first byte after command */
 		if (status == (I2C_SL_IRQ | RNW | RCVD)) {
-			udelay(33);
+			usleep_range(33, 43);
 			if (nvec->rx->data[0] != 0x01) {
 				dev_err(nvec->dev,
 					"Read without prior read command\n");
@@ -718,7 +718,7 @@ static irqreturn_t nvec_interrupt(int irq, void *dev)
 	 * We experience less incomplete messages with this delay than without
 	 * it, but we don't know why. Help is appreciated.
 	 */
-	udelay(100);
+	usleep_range(100,200);
 
 	return IRQ_HANDLED;
 }
-- 
2.9.3



^ permalink raw reply related	[flat|nested] 6+ messages in thread
* Re: [Outreachy kernel] [PATCH] staging: nvec: Replace udelay by usleep_range
  2017-03-07 12:52 [PATCH] staging: nvec: Replace udelay by usleep_range Sreya Mittal
@ 2017-03-07 15:52 ` Julia Lawall
  2017-03-07 19:14   ` Sreya Mittal
  0 siblings, 1 reply; 6+ messages in thread
From: Julia Lawall @ 2017-03-07 15:52 UTC (permalink / raw)
  To: Sreya Mittal; +Cc: outreachy-kernel, Marc Dietrich, Greg Kroah-Hartman



On Tue, 7 Mar 2017, Sreya Mittal wrote:

> Replace udelay by usleep_range.
> Fixes the checkpatch issue:
> usleep_range is preferred over udelay
>
> In Documentation/timers/timers-howto.txt,
> it is mentioned that udelay should be used
> for a few microseconds(less than 10), and
> usleep_range should be preferred for 10
> microseconds to 20 milliseconds.
>
> Signed-off-by: Sreya Mittal <sreyamittal5@gmail.com>
> ---
>  drivers/staging/nvec/nvec.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/staging/nvec/nvec.c b/drivers/staging/nvec/nvec.c
> index c1feccf..5fab241 100644
> --- a/drivers/staging/nvec/nvec.c
> +++ b/drivers/staging/nvec/nvec.c
> @@ -631,7 +631,7 @@ static irqreturn_t nvec_interrupt(int irq, void *dev)
>  		break;
>  	case 2:		/* first byte after command */
>  		if (status == (I2C_SL_IRQ | RNW | RCVD)) {
> -			udelay(33);
> +			usleep_range(33, 43);

The key point is how do you choose the upper bound.  If you don't have a
good rationale for your choice, it would be better not to make the change.

julia

>  			if (nvec->rx->data[0] != 0x01) {
>  				dev_err(nvec->dev,
>  					"Read without prior read command\n");
> @@ -718,7 +718,7 @@ static irqreturn_t nvec_interrupt(int irq, void *dev)
>  	 * We experience less incomplete messages with this delay than without
>  	 * it, but we don't know why. Help is appreciated.
>  	 */
> -	udelay(100);
> +	usleep_range(100,200);
>
>  	return IRQ_HANDLED;
>  }
> --
> 2.9.3
>
> --
> You received this message because you are subscribed to the Google Groups "outreachy-kernel" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to outreachy-kernel+unsubscribe@googlegroups.com.
> To post to this group, send email to outreachy-kernel@googlegroups.com.
> To view this discussion on the web visit https://groups.google.com/d/msgid/outreachy-kernel/20170307125256.3998-1-sreyamittal5%40gmail.com.
> For more options, visit https://groups.google.com/d/optout.
>


^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [Outreachy kernel] [PATCH] staging: nvec: Replace udelay by usleep_range
  2017-03-07 15:52 ` [Outreachy kernel] " Julia Lawall
@ 2017-03-07 19:14   ` Sreya Mittal
  2017-03-07 20:47     ` [Outreachy kernel] [PATCH] staging: nvec: Replace udelay byusleep_range Marc Dietrich
  0 siblings, 1 reply; 6+ messages in thread
From: Sreya Mittal @ 2017-03-07 19:14 UTC (permalink / raw)
  To: outreachy-kernel; +Cc: sreyamittal5, marvin24, gregkh


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On Tuesday, March 7, 2017 at 9:22:16 PM UTC+5:30, Julia Lawall wrote:
>
>
>
> On Tue, 7 Mar 2017, Sreya Mittal wrote: 
>
> > Replace udelay by usleep_range. 
> > Fixes the checkpatch issue: 
> > usleep_range is preferred over udelay 
> > 
> > In Documentation/timers/timers-howto.txt, 
> > it is mentioned that udelay should be used 
> > for a few microseconds(less than 10), and 
> > usleep_range should be preferred for 10 
> > microseconds to 20 milliseconds. 
> > 
> > Signed-off-by: Sreya Mittal <sreyam...@gmail.com <javascript:>> 
> > --- 
> >  drivers/staging/nvec/nvec.c | 4 ++-- 
> >  1 file changed, 2 insertions(+), 2 deletions(-) 
> > 
> > diff --git a/drivers/staging/nvec/nvec.c b/drivers/staging/nvec/nvec.c 
> > index c1feccf..5fab241 100644 
> > --- a/drivers/staging/nvec/nvec.c 
> > +++ b/drivers/staging/nvec/nvec.c 
> > @@ -631,7 +631,7 @@ static irqreturn_t nvec_interrupt(int irq, void 
> *dev) 
> >                  break; 
> >          case 2:                /* first byte after command */ 
> >                  if (status == (I2C_SL_IRQ | RNW | RCVD)) { 
> > -                        udelay(33); 
> > +                        usleep_range(33, 43); 
>
> The key point is how do you choose the upper bound.  If you don't have a 
> good rationale for your choice, it would be better not to make the change. 
>

Could you please give some hint(s) regarding the choice of upper bound and
what possibly can be a good rationale for it?

Sreya 
 

>
> julia 
>
> >                          if (nvec->rx->data[0] != 0x01) { 
> >                                  dev_err(nvec->dev, 
> >                                          "Read without prior read 
> command\n"); 
> > @@ -718,7 +718,7 @@ static irqreturn_t nvec_interrupt(int irq, void 
> *dev) 
> >           * We experience less incomplete messages with this delay than 
> without 
> >           * it, but we don't know why. Help is appreciated. 
> >           */ 
> > -        udelay(100); 
> > +        usleep_range(100,200); 
> > 
> >          return IRQ_HANDLED; 
> >  } 
> > -- 
> > 2.9.3 
> > 
> > -- 
> > You received this message because you are subscribed to the Google 
> Groups "outreachy-kernel" group. 
> > To unsubscribe from this group and stop receiving emails from it, send 
> an email to outreachy-kern...@googlegroups.com <javascript:>. 
> > To post to this group, send email to outreach...@googlegroups.com 
> <javascript:>. 
> > To view this discussion on the web visit 
> https://groups.google.com/d/msgid/outreachy-kernel/20170307125256.3998-1-sreyamittal5%40gmail.com. 
>
> > For more options, visit https://groups.google.com/d/optout. 
> > 
>

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^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [Outreachy kernel] [PATCH] staging: nvec: Replace udelay byusleep_range
  2017-03-07 19:14   ` Sreya Mittal
@ 2017-03-07 20:47     ` Marc Dietrich
  2017-03-07 21:21       ` Sreya Mittal
  0 siblings, 1 reply; 6+ messages in thread
From: Marc Dietrich @ 2017-03-07 20:47 UTC (permalink / raw)
  To: Sreya Mittal; +Cc: outreachy-kernel, gregkh, Julia Lawall


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Am Dienstag, 7. März 2017, 20:14:06 CET schrieb Sreya Mittal:
> On Tuesday, March 7, 2017 at 9:22:16 PM UTC+5:30, Julia Lawall wrote:
> > On Tue, 7 Mar 2017, Sreya Mittal wrote:
> > > Replace udelay by usleep_range.
> > > Fixes the checkpatch issue:
> > > usleep_range is preferred over udelay
> > > 
> > > In Documentation/timers/timers-howto.txt,
> > > it is mentioned that udelay should be used
> > > for a few microseconds(less than 10), and
> > > usleep_range should be preferred for 10
> > > microseconds to 20 milliseconds.
> > > 
> > > Signed-off-by: Sreya Mittal <sreyam...@gmail.com <javascript:>>
> > > ---
> > > 
> > >  drivers/staging/nvec/nvec.c | 4 ++--
> > >  1 file changed, 2 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/drivers/staging/nvec/nvec.c b/drivers/staging/nvec/nvec.c
> > > index c1feccf..5fab241 100644
> > > --- a/drivers/staging/nvec/nvec.c
> > > +++ b/drivers/staging/nvec/nvec.c
> > > @@ -631,7 +631,7 @@ static irqreturn_t nvec_interrupt(int irq, void
> > 
> > *dev)
> > 
> > >                  break;
> > >          
> > >          case 2:                /* first byte after command */
> > >          
> > >                  if (status == (I2C_SL_IRQ | RNW | RCVD)) {
> > > 
> > > -                        udelay(33);
> > > +                        usleep_range(33, 43);
> > 
> > The key point is how do you choose the upper bound.  If you don't have a
> > good rationale for your choice, it would be better not to make the change.
> 
> Could you please give some hint(s) regarding the choice of upper bound and
> what possibly can be a good rationale for it?

I n'acked a similar patch a few days ago. See https://lkml.org/lkml/2017/3/2/293.

Maybe it would be good to add a hint to the relevant tutorials to first check if a similar patch 
has been submitted before.

Marc

Sreya

> 
> > julia
> > 
> > >                          if (nvec->rx->data[0] != 0x01) {
> > >                          
> > >                                  dev_err(nvec->dev,
> > >                                  
> > >                                          "Read without prior read
> > 
> > command\n");
> > 
> > > @@ -718,7 +718,7 @@ static irqreturn_t nvec_interrupt(int irq, void
> > 
> > *dev)
> > 
> > >           * We experience less incomplete messages with this delay than
> > 
> > without
> > 
> > >           * it, but we don't know why. Help is appreciated.
> > >           */
> > > 
> > > -        udelay(100);
> > > +        usleep_range(100,200);
> > > 
> > >          return IRQ_HANDLED;
> > >  
> > >  }
> > 
> > Groups "outreachy-kernel" group.
> > 
> > > To unsubscribe from this group and stop receiving emails from it, send
> > 
> > an email to outreachy-kern...@googlegroups.com <javascript:>.
> > 
> > > To post to this group, send email to outreach...@googlegroups.com
> > 
> > <javascript:>.
> > 
> > > To view this discussion on the web visit
> > 
> > https://groups.google.com/d/msgid/outreachy-kernel/20170307125256.3998-1-s
> > reyamittal5%40gmail.com.> 
> > > For more options, visit https://groups.google.com/d/optout.



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^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [Outreachy kernel] [PATCH] staging: nvec: Replace udelay byusleep_range
  2017-03-07 20:47     ` [Outreachy kernel] [PATCH] staging: nvec: Replace udelay byusleep_range Marc Dietrich
@ 2017-03-07 21:21       ` Sreya Mittal
  2017-03-07 21:32         ` Julia Lawall
  0 siblings, 1 reply; 6+ messages in thread
From: Sreya Mittal @ 2017-03-07 21:21 UTC (permalink / raw)
  To: outreachy-kernel; +Cc: sreyamittal5, gregkh, julia.lawall, marvin24


[-- Attachment #1.1: Type: text/plain, Size: 3566 bytes --]



On Wednesday, March 8, 2017 at 2:17:36 AM UTC+5:30, Marc Dietrich wrote:
>
> Am Dienstag, 7. März 2017, 20:14:06 CET schrieb Sreya Mittal:
>
> > On Tuesday, March 7, 2017 at 9:22:16 PM UTC+5:30, Julia Lawall wrote:
>
> > > On Tue, 7 Mar 2017, Sreya Mittal wrote:
>
> > > > Replace udelay by usleep_range.
>
> > > > Fixes the checkpatch issue:
>
> > > > usleep_range is preferred over udelay
>
> > > > 
>
> > > > In Documentation/timers/timers-howto.txt,
>
> > > > it is mentioned that udelay should be used
>
> > > > for a few microseconds(less than 10), and
>
> > > > usleep_range should be preferred for 10
>
> > > > microseconds to 20 milliseconds.
>
> > > > 
>
> > > > Signed-off-by: Sreya Mittal <sreyam...@gmail.com <javascript:>>
>
> > > > ---
>
> > > > 
>
> > > > drivers/staging/nvec/nvec.c | 4 ++--
>
> > > > 1 file changed, 2 insertions(+), 2 deletions(-)
>
> > > > 
>
> > > > diff --git a/drivers/staging/nvec/nvec.c 
> b/drivers/staging/nvec/nvec.c
>
> > > > index c1feccf..5fab241 100644
>
> > > > --- a/drivers/staging/nvec/nvec.c
>
> > > > +++ b/drivers/staging/nvec/nvec.c
>
> > > > @@ -631,7 +631,7 @@ static irqreturn_t nvec_interrupt(int irq, void
>
> > > 
>
> > > *dev)
>
> > > 
>
> > > > break;
>
> > > > 
>
> > > > case 2: /* first byte after command */
>
> > > > 
>
> > > > if (status == (I2C_SL_IRQ | RNW | RCVD)) {
>
> > > > 
>
> > > > - udelay(33);
>
> > > > + usleep_range(33, 43);
>
> > > 
>
> > > The key point is how do you choose the upper bound. If you don't have a
>
> > > good rationale for your choice, it would be better not to make the 
> change.
>
> > 
>
> > Could you please give some hint(s) regarding the choice of upper bound 
> and
>
> > what possibly can be a good rationale for it?
>
>  
>
> I n'acked a similar patch a few days ago. See 
> https://lkml.org/lkml/2017/3/2/293.
>
>  
>
> Maybe it would be good to add a hint to the relevant tutorials to first 
> check if a similar patch has been submitted before.
>
>  
>
> Marc
>

Hi,

Thank you for the link. My bad that I didn't check whether a similar patch 
has been submitted before.

Sreya
 

>  
>
> Sreya
>
>  
>
> > 
>
> > > julia
>
> > > 
>
> > > > if (nvec->rx->data[0] != 0x01) {
>
> > > > 
>
> > > > dev_err(nvec->dev,
>
> > > > 
>
> > > > "Read without prior read
>
> > > 
>
> > > command\n");
>
> > > 
>
> > > > @@ -718,7 +718,7 @@ static irqreturn_t nvec_interrupt(int irq, void
>
> > > 
>
> > > *dev)
>
> > > 
>
> > > > * We experience less incomplete messages with this delay than
>
> > > 
>
> > > without
>
> > > 
>
> > > > * it, but we don't know why. Help is appreciated.
>
> > > > */
>
> > > > 
>
> > > > - udelay(100);
>
> > > > + usleep_range(100,200);
>
> > > > 
>
> > > > return IRQ_HANDLED;
>
> > > > 
>
> > > > }
>
> > > 
>
> > > Groups "outreachy-kernel" group.
>
> > > 
>
> > > > To unsubscribe from this group and stop receiving emails from it, 
> send
>
> > > 
>
> > > an email to outreachy-kern...@googlegroups.com <javascript:>.
>
> > > 
>
> > > > To post to this group, send email to outreach...@googlegroups.com
>
> > > 
>
> > > <javascript:>.
>
> > > 
>
> > > > To view this discussion on the web visit
>
> > > 
>
> > > 
> https://groups.google.com/d/msgid/outreachy-kernel/20170307125256.3998-1-s
>
> > > reyamittal5%40gmail.com.> 
>
> > > > For more options, visit https://groups.google.com/d/optout.
>
>  
>
>  
>

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^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [Outreachy kernel] [PATCH] staging: nvec: Replace udelay byusleep_range
  2017-03-07 21:21       ` Sreya Mittal
@ 2017-03-07 21:32         ` Julia Lawall
  0 siblings, 0 replies; 6+ messages in thread
From: Julia Lawall @ 2017-03-07 21:32 UTC (permalink / raw)
  To: Sreya Mittal; +Cc: outreachy-kernel, gregkh, marvin24

[-- Attachment #1: Type: text/plain, Size: 4687 bytes --]



On Tue, 7 Mar 2017, Sreya Mittal wrote:

>
>
> On Wednesday, March 8, 2017 at 2:17:36 AM UTC+5:30, Marc Dietrich wrote:
>
>       Am Dienstag, 7. März 2017, 20:14:06 CET schrieb Sreya Mittal:
>
>       > On Tuesday, March 7, 2017 at 9:22:16 PM UTC+5:30, Julia Lawall
>       wrote:
>
>       > > On Tue, 7 Mar 2017, Sreya Mittal wrote:
>
>       > > > Replace udelay by usleep_range.
>
>       > > > Fixes the checkpatch issue:
>
>       > > > usleep_range is preferred over udelay
>
>       > > >
>
>       > > > In Documentation/timers/timers-howto.txt,
>
>       > > > it is mentioned that udelay should be used
>
>       > > > for a few microseconds(less than 10), and
>
>       > > > usleep_range should be preferred for 10
>
>       > > > microseconds to 20 milliseconds.
>
>       > > >
>
>       > > > Signed-off-by: Sreya Mittal <sreyam...@gmail.com
>       <javascript:>>
>
>       > > > ---
>
>       > > >
>
>       > > > drivers/staging/nvec/nvec.c | 4 ++--
>
>       > > > 1 file changed, 2 insertions(+), 2 deletions(-)
>
>       > > >
>
>       > > > diff --git a/drivers/staging/nvec/nvec.c
>       b/drivers/staging/nvec/nvec.c
>
>       > > > index c1feccf..5fab241 100644
>
>       > > > --- a/drivers/staging/nvec/nvec.c
>
>       > > > +++ b/drivers/staging/nvec/nvec.c
>
>       > > > @@ -631,7 +631,7 @@ static irqreturn_t nvec_interrupt(int
>       irq, void
>
>       > >
>
>       > > *dev)
>
>       > >
>
>       > > > break;
>
>       > > >
>
>       > > > case 2: /* first byte after command */
>
>       > > >
>
>       > > > if (status == (I2C_SL_IRQ | RNW | RCVD)) {
>
>       > > >
>
>       > > > - udelay(33);
>
>       > > > + usleep_range(33, 43);
>
>       > >
>
>       > > The key point is how do you choose the upper bound. If you
>       don't have a
>
>       > > good rationale for your choice, it would be better not to
>       make the change.
>
>       >
>
>       > Could you please give some hint(s) regarding the choice of
>       upper bound and
>
>       > what possibly can be a good rationale for it?
>
>        
>
>       I n'acked a similar patch a few days ago. See
>       https://lkml.org/lkml/2017/3/2/293.
>
>        
>
>       Maybe it would be good to add a hint to the relevant tutorials
>       to first check if a similar patch has been submitted before.

I have added some text to this effect.  Thank you for the suggestion.

julia

>
>        
>
>       Marc
>
>
> Hi,
>
> Thank you for the link. My bad that I didn't check whether a similar patch
> has been submitted before.
>
> Sreya
>  
>
>        
>
>       Sreya
>
>        
>
>       >
>
>       > > julia
>
>       > >
>
>       > > > if (nvec->rx->data[0] != 0x01) {
>
>       > > >
>
>       > > > dev_err(nvec->dev,
>
>       > > >
>
>       > > > "Read without prior read
>
>       > >
>
>       > > command\n");
>
>       > >
>
>       > > > @@ -718,7 +718,7 @@ static irqreturn_t nvec_interrupt(int
>       irq, void
>
>       > >
>
>       > > *dev)
>
>       > >
>
>       > > > * We experience less incomplete messages with this delay
>       than
>
>       > >
>
>       > > without
>
>       > >
>
>       > > > * it, but we don't know why. Help is appreciated.
>
>       > > > */
>
>       > > >
>
>       > > > - udelay(100);
>
>       > > > + usleep_range(100,200);
>
>       > > >
>
>       > > > return IRQ_HANDLED;
>
>       > > >
>
>       > > > }
>
>       > >
>
>       > > Groups "outreachy-kernel" group.
>
>       > >
>
>       > > > To unsubscribe from this group and stop receiving emails
>       from it, send
>
>       > >
>
>       > > an email to outreachy-kern...@googlegroups.com
>       <javascript:>.
>
>       > >
>
>       > > > To post to this group, send email to
>       outreach...@googlegroups.com
>
>       > >
>
>       > > <javascript:>.
>
>       > >
>
>       > > > To view this discussion on the web visit
>
>       > >
>
>       > >
>       https://groups.google.com/d/msgid/outreachy-kernel/20170307125256.3998-1-s
>
>       > > reyamittal5%40gmail.com.>
>
>       > > > For more options, visit
>       https://groups.google.com/d/optout.
>
>        
>
>        
>
> --
> You received this message because you are subscribed to the Google Groups
> "outreachy-kernel" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to outreachy-kernel+unsubscribe@googlegroups.com.
> To post to this group, send email to outreachy-kernel@googlegroups.com.
> To view this discussion on the web visithttps://groups.google.com/d/msgid/outreachy-kernel/9c43c46e-93b5-46fd-ba6f-
> ccdf5929d380%40googlegroups.com.
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^ permalink raw reply	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2017-03-07 21:32 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-03-07 12:52 [PATCH] staging: nvec: Replace udelay by usleep_range Sreya Mittal
2017-03-07 15:52 ` [Outreachy kernel] " Julia Lawall
2017-03-07 19:14   ` Sreya Mittal
2017-03-07 20:47     ` [Outreachy kernel] [PATCH] staging: nvec: Replace udelay byusleep_range Marc Dietrich
2017-03-07 21:21       ` Sreya Mittal
2017-03-07 21:32         ` Julia Lawall

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