Re: [PATCH 10/11] spi: add more debug prints in s3c64xx

2015-06-04 Thread Mark Brown
On Thu, Jun 04, 2015 at 12:52:19PM +0200, Michal Suchanek wrote:

> There is no code interdependency with the other patches so if it's
> preferred I can send patches like this separately.

Yes, that's better practice.


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Re: [PATCH 10/11] spi: add more debug prints in s3c64xx

2015-06-04 Thread Michal Suchanek
On 4 June 2015 at 12:26, Mark Brown  wrote:
> On Thu, Jun 04, 2015 at 11:33:37AM +0200, Michal Suchanek wrote:
>> On 4 June 2015 at 11:16, Mark Brown  wrote:
>
>> > Also for this patch (which just adds some trace) there isn't any clear
>> > reason for it to be sent as part of the series at all, it doesn't help
>> > deliver the functionality and doesn't depend on the rest of the series.
>
>> I used this patch to add missing information to dmesg output so I
>> could diagnose the SPI failures so I think it is relevant.
>
> The fact that you used this to debug problems is not relevant to any fix
> you might have developed for those problems; the fix can be explained
> without needing to know how you got there.  Similarly the debugging is
> hopefully useful in general without needing to know which particular
> problem prompted it's creation.

Yes, this patch should be meaningful on its own.

The ultimate purpose of this patch series is to make the SPI NOR flash
chip usable on boards of which I have 1 sample. If the results on
boards other than mine happen to be different the debug prints will be
useful for users of this flash chip.

There is no code interdependency with the other patches so if it's
preferred I can send patches like this separately.

>
>> To print a clock name you AFAICT need this header. I think this is an
>> abstraction problem in the clock framework. Fixing the abstraction
>> problem with clock framework would only grow the list of recipients
>> which is already so long you complain about it.
>
> This is a bit of a warning sign that the series isn't very focused.
> It's also just not good practice, sending patches with obvious problems
> (especially obvious problems that aren't clearly flagged up as something
> temporary) will frustrate reviewers and can often lead to other issues
> being obscured.

As has been pointed out public interface already exists for getting
the clock name so the issue here is cosmetic.

Thanks

Michal
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Re: [PATCH 10/11] spi: add more debug prints in s3c64xx

2015-06-04 Thread Mark Brown
On Thu, Jun 04, 2015 at 11:33:37AM +0200, Michal Suchanek wrote:
> On 4 June 2015 at 11:16, Mark Brown  wrote:

> > Also for this patch (which just adds some trace) there isn't any clear
> > reason for it to be sent as part of the series at all, it doesn't help
> > deliver the functionality and doesn't depend on the rest of the series.

> I used this patch to add missing information to dmesg output so I
> could diagnose the SPI failures so I think it is relevant.

The fact that you used this to debug problems is not relevant to any fix
you might have developed for those problems; the fix can be explained
without needing to know how you got there.  Similarly the debugging is
hopefully useful in general without needing to know which particular
problem prompted it's creation.

> To print a clock name you AFAICT need this header. I think this is an
> abstraction problem in the clock framework. Fixing the abstraction
> problem with clock framework would only grow the list of recipients
> which is already so long you complain about it.

This is a bit of a warning sign that the series isn't very focused.
It's also just not good practice, sending patches with obvious problems
(especially obvious problems that aren't clearly flagged up as something
temporary) will frustrate reviewers and can often lead to other issues
being obscured.


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Re: [PATCH 10/11] spi: add more debug prints in s3c64xx

2015-06-04 Thread Mark Brown
On Thu, Jun 04, 2015 at 11:30:15AM +0200, Geert Uytterhoeven wrote:
> On Thu, Jun 4, 2015 at 11:16 AM, Mark Brown  wrote:
> >> --- a/drivers/spi/spi-s3c64xx.c
> >> +++ b/drivers/spi/spi-s3c64xx.c
> >> @@ -18,6 +18,7 @@
> >>  #include 
> >>  #include 
> >>  #include 
> >> +#include 

> > Whatever you're doing here this indicates that there's a very big
> > abstraction problem going on.

> I guess it's needed for __clk_get_name(), which can be avoided by using
> the "%pC" printf format specifier instead.

Right, or by adding an externally usable API - the point is that using
internal functions in a client driver is a big red flag.


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Re: [PATCH 10/11] spi: add more debug prints in s3c64xx

2015-06-04 Thread Michal Suchanek
Hello,

On 4 June 2015 at 11:16, Mark Brown  wrote:
> On Wed, Jun 03, 2015 at 09:26:42PM -, Michal Suchanek wrote:
>> The SPI NOR transfers mysteriously fail so add more debug prints about
>> SPI transactions.
>
> Please try to only send patches to relevant people - the list of
> recipients for this is so large that it only barely fits on a single
> screen in my mail client.
>
> Also for this patch (which just adds some trace) there isn't any clear
> reason for it to be sent as part of the series at all, it doesn't help
> deliver the functionality and doesn't depend on the rest of the series.

I used this patch to add missing information to dmesg output so I
could diagnose the SPI failures so I think it is relevant.

The failure is reported by the s3c64xx but the root cause is pl330 not
finishing a DMA transfer.

It is non-obvious that this is the issue. The information that a call
to pl330 failed is only available in the s3c64xx driver and not SPI
core so I think there is no reasonable way to debug this issue other
than adding prints in s3c64xx. This issue is not completely resolved
or even well tested (I have only single board to test with) so these
prints remain relevant in my view.

>
>> --- a/drivers/spi/spi-s3c64xx.c
>> +++ b/drivers/spi/spi-s3c64xx.c
>> @@ -18,6 +18,7 @@
>>  #include 
>>  #include 
>>  #include 
>> +#include 
>
> Whatever you're doing here this indicates that there's a very big
> abstraction problem going on.

I wanted to print a clock name in case the information was relevant
for the issue at hand.

To print a clock name you AFAICT need this header. I think this is an
abstraction problem in the clock framework. Fixing the abstraction
problem with clock framework would only grow the list of recipients
which is already so long you complain about it.

It turns out that in this case the clock was not at fault so I did not
need the clock name in the end.

>
>> + pr_debug("%s %s %s waiting for %ims transferring %zubytes@%iHz",
>> +  __func__, sdd->pdev ? dev_name(>pdev->dev) : NULL,
>> +  dev_name(>master->dev),
>> +  ms, xfer->len, sdd->cur_speed);
>
> I'd say dev_dbg() but more generally this is just tracing things that
> seem to be already covered by the trace points already present in the
> core, the same goes for most of the rest of it.  If there's things
> missing from the existing trace it seems better to add to it.

There is master and slave device involved but it's certainly possible
to use dev_dbg on one of them and pass the other as string.

Thanks

Michal
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Re: [PATCH 10/11] spi: add more debug prints in s3c64xx

2015-06-04 Thread Geert Uytterhoeven
On Thu, Jun 4, 2015 at 11:16 AM, Mark Brown  wrote:
>> --- a/drivers/spi/spi-s3c64xx.c
>> +++ b/drivers/spi/spi-s3c64xx.c
>> @@ -18,6 +18,7 @@
>>  #include 
>>  #include 
>>  #include 
>> +#include 
>
> Whatever you're doing here this indicates that there's a very big
> abstraction problem going on.

I guess it's needed for __clk_get_name(), which can be avoided by using
the "%pC" printf format specifier instead.

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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Re: [PATCH 10/11] spi: add more debug prints in s3c64xx

2015-06-04 Thread Mark Brown
On Wed, Jun 03, 2015 at 09:26:42PM -, Michal Suchanek wrote:
> The SPI NOR transfers mysteriously fail so add more debug prints about
> SPI transactions.

Please try to only send patches to relevant people - the list of
recipients for this is so large that it only barely fits on a single
screen in my mail client.

Also for this patch (which just adds some trace) there isn't any clear
reason for it to be sent as part of the series at all, it doesn't help
deliver the functionality and doesn't depend on the rest of the series.

> --- a/drivers/spi/spi-s3c64xx.c
> +++ b/drivers/spi/spi-s3c64xx.c
> @@ -18,6 +18,7 @@
>  #include 
>  #include 
>  #include 
> +#include 

Whatever you're doing here this indicates that there's a very big
abstraction problem going on.

> + pr_debug("%s %s %s waiting for %ims transferring %zubytes@%iHz",
> +  __func__, sdd->pdev ? dev_name(>pdev->dev) : NULL,
> +  dev_name(>master->dev),
> +  ms, xfer->len, sdd->cur_speed);

I'd say dev_dbg() but more generally this is just tracing things that
seem to be already covered by the trace points already present in the
core, the same goes for most of the rest of it.  If there's things
missing from the existing trace it seems better to add to it.


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Re: [PATCH 10/11] spi: add more debug prints in s3c64xx

2015-06-04 Thread Mark Brown
On Wed, Jun 03, 2015 at 09:26:42PM -, Michal Suchanek wrote:
 The SPI NOR transfers mysteriously fail so add more debug prints about
 SPI transactions.

Please try to only send patches to relevant people - the list of
recipients for this is so large that it only barely fits on a single
screen in my mail client.

Also for this patch (which just adds some trace) there isn't any clear
reason for it to be sent as part of the series at all, it doesn't help
deliver the functionality and doesn't depend on the rest of the series.

 --- a/drivers/spi/spi-s3c64xx.c
 +++ b/drivers/spi/spi-s3c64xx.c
 @@ -18,6 +18,7 @@
  #include linux/interrupt.h
  #include linux/delay.h
  #include linux/clk.h
 +#include linux/clk-provider.h

Whatever you're doing here this indicates that there's a very big
abstraction problem going on.

 + pr_debug(%s %s %s waiting for %ims transferring %zubytes@%iHz,
 +  __func__, sdd-pdev ? dev_name(sdd-pdev-dev) : NULL,
 +  dev_name(sdd-master-dev),
 +  ms, xfer-len, sdd-cur_speed);

I'd say dev_dbg() but more generally this is just tracing things that
seem to be already covered by the trace points already present in the
core, the same goes for most of the rest of it.  If there's things
missing from the existing trace it seems better to add to it.


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Re: [PATCH 10/11] spi: add more debug prints in s3c64xx

2015-06-04 Thread Geert Uytterhoeven
On Thu, Jun 4, 2015 at 11:16 AM, Mark Brown broo...@kernel.org wrote:
 --- a/drivers/spi/spi-s3c64xx.c
 +++ b/drivers/spi/spi-s3c64xx.c
 @@ -18,6 +18,7 @@
  #include linux/interrupt.h
  #include linux/delay.h
  #include linux/clk.h
 +#include linux/clk-provider.h

 Whatever you're doing here this indicates that there's a very big
 abstraction problem going on.

I guess it's needed for __clk_get_name(), which can be avoided by using
the %pC printf format specifier instead.

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say programmer or something like that.
-- Linus Torvalds
--
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Re: [PATCH 10/11] spi: add more debug prints in s3c64xx

2015-06-04 Thread Mark Brown
On Thu, Jun 04, 2015 at 12:52:19PM +0200, Michal Suchanek wrote:

 There is no code interdependency with the other patches so if it's
 preferred I can send patches like this separately.

Yes, that's better practice.


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Re: [PATCH 10/11] spi: add more debug prints in s3c64xx

2015-06-04 Thread Mark Brown
On Thu, Jun 04, 2015 at 11:33:37AM +0200, Michal Suchanek wrote:
 On 4 June 2015 at 11:16, Mark Brown broo...@kernel.org wrote:

  Also for this patch (which just adds some trace) there isn't any clear
  reason for it to be sent as part of the series at all, it doesn't help
  deliver the functionality and doesn't depend on the rest of the series.

 I used this patch to add missing information to dmesg output so I
 could diagnose the SPI failures so I think it is relevant.

The fact that you used this to debug problems is not relevant to any fix
you might have developed for those problems; the fix can be explained
without needing to know how you got there.  Similarly the debugging is
hopefully useful in general without needing to know which particular
problem prompted it's creation.

 To print a clock name you AFAICT need this header. I think this is an
 abstraction problem in the clock framework. Fixing the abstraction
 problem with clock framework would only grow the list of recipients
 which is already so long you complain about it.

This is a bit of a warning sign that the series isn't very focused.
It's also just not good practice, sending patches with obvious problems
(especially obvious problems that aren't clearly flagged up as something
temporary) will frustrate reviewers and can often lead to other issues
being obscured.


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Re: [PATCH 10/11] spi: add more debug prints in s3c64xx

2015-06-04 Thread Michal Suchanek
On 4 June 2015 at 12:26, Mark Brown broo...@kernel.org wrote:
 On Thu, Jun 04, 2015 at 11:33:37AM +0200, Michal Suchanek wrote:
 On 4 June 2015 at 11:16, Mark Brown broo...@kernel.org wrote:

  Also for this patch (which just adds some trace) there isn't any clear
  reason for it to be sent as part of the series at all, it doesn't help
  deliver the functionality and doesn't depend on the rest of the series.

 I used this patch to add missing information to dmesg output so I
 could diagnose the SPI failures so I think it is relevant.

 The fact that you used this to debug problems is not relevant to any fix
 you might have developed for those problems; the fix can be explained
 without needing to know how you got there.  Similarly the debugging is
 hopefully useful in general without needing to know which particular
 problem prompted it's creation.

Yes, this patch should be meaningful on its own.

The ultimate purpose of this patch series is to make the SPI NOR flash
chip usable on boards of which I have 1 sample. If the results on
boards other than mine happen to be different the debug prints will be
useful for users of this flash chip.

There is no code interdependency with the other patches so if it's
preferred I can send patches like this separately.


 To print a clock name you AFAICT need this header. I think this is an
 abstraction problem in the clock framework. Fixing the abstraction
 problem with clock framework would only grow the list of recipients
 which is already so long you complain about it.

 This is a bit of a warning sign that the series isn't very focused.
 It's also just not good practice, sending patches with obvious problems
 (especially obvious problems that aren't clearly flagged up as something
 temporary) will frustrate reviewers and can often lead to other issues
 being obscured.

As has been pointed out public interface already exists for getting
the clock name so the issue here is cosmetic.

Thanks

Michal
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: [PATCH 10/11] spi: add more debug prints in s3c64xx

2015-06-04 Thread Michal Suchanek
Hello,

On 4 June 2015 at 11:16, Mark Brown broo...@kernel.org wrote:
 On Wed, Jun 03, 2015 at 09:26:42PM -, Michal Suchanek wrote:
 The SPI NOR transfers mysteriously fail so add more debug prints about
 SPI transactions.

 Please try to only send patches to relevant people - the list of
 recipients for this is so large that it only barely fits on a single
 screen in my mail client.

 Also for this patch (which just adds some trace) there isn't any clear
 reason for it to be sent as part of the series at all, it doesn't help
 deliver the functionality and doesn't depend on the rest of the series.

I used this patch to add missing information to dmesg output so I
could diagnose the SPI failures so I think it is relevant.

The failure is reported by the s3c64xx but the root cause is pl330 not
finishing a DMA transfer.

It is non-obvious that this is the issue. The information that a call
to pl330 failed is only available in the s3c64xx driver and not SPI
core so I think there is no reasonable way to debug this issue other
than adding prints in s3c64xx. This issue is not completely resolved
or even well tested (I have only single board to test with) so these
prints remain relevant in my view.


 --- a/drivers/spi/spi-s3c64xx.c
 +++ b/drivers/spi/spi-s3c64xx.c
 @@ -18,6 +18,7 @@
  #include linux/interrupt.h
  #include linux/delay.h
  #include linux/clk.h
 +#include linux/clk-provider.h

 Whatever you're doing here this indicates that there's a very big
 abstraction problem going on.

I wanted to print a clock name in case the information was relevant
for the issue at hand.

To print a clock name you AFAICT need this header. I think this is an
abstraction problem in the clock framework. Fixing the abstraction
problem with clock framework would only grow the list of recipients
which is already so long you complain about it.

It turns out that in this case the clock was not at fault so I did not
need the clock name in the end.


 + pr_debug(%s %s %s waiting for %ims transferring %zubytes@%iHz,
 +  __func__, sdd-pdev ? dev_name(sdd-pdev-dev) : NULL,
 +  dev_name(sdd-master-dev),
 +  ms, xfer-len, sdd-cur_speed);

 I'd say dev_dbg() but more generally this is just tracing things that
 seem to be already covered by the trace points already present in the
 core, the same goes for most of the rest of it.  If there's things
 missing from the existing trace it seems better to add to it.

There is master and slave device involved but it's certainly possible
to use dev_dbg on one of them and pass the other as string.

Thanks

Michal
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
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Re: [PATCH 10/11] spi: add more debug prints in s3c64xx

2015-06-04 Thread Mark Brown
On Thu, Jun 04, 2015 at 11:30:15AM +0200, Geert Uytterhoeven wrote:
 On Thu, Jun 4, 2015 at 11:16 AM, Mark Brown broo...@kernel.org wrote:
  --- a/drivers/spi/spi-s3c64xx.c
  +++ b/drivers/spi/spi-s3c64xx.c
  @@ -18,6 +18,7 @@
   #include linux/interrupt.h
   #include linux/delay.h
   #include linux/clk.h
  +#include linux/clk-provider.h

  Whatever you're doing here this indicates that there's a very big
  abstraction problem going on.

 I guess it's needed for __clk_get_name(), which can be avoided by using
 the %pC printf format specifier instead.

Right, or by adding an externally usable API - the point is that using
internal functions in a client driver is a big red flag.


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Re: [PATCH 10/11] spi: add more debug prints in s3c64xx

2015-06-03 Thread Marek Vasut
On Wednesday, June 03, 2015 at 11:26:42 PM, Michal Suchanek wrote:
> The SPI NOR transfers mysteriously fail so add more debug prints about
> SPI transactions.
> 
> Signed-off-by: Michal Suchanek 

dev_dbg() and friends would certainly be nicer here.

Best regards,
Marek Vasut
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Re: [PATCH 10/11] spi: add more debug prints in s3c64xx

2015-06-03 Thread Marek Vasut
On Wednesday, June 03, 2015 at 11:26:42 PM, Michal Suchanek wrote:
 The SPI NOR transfers mysteriously fail so add more debug prints about
 SPI transactions.
 
 Signed-off-by: Michal Suchanek hramr...@gmail.com

dev_dbg() and friends would certainly be nicer here.

Best regards,
Marek Vasut
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