[U-Boot] [PATCH] video: ipu_common: fix build error

[U-Boot] [PATCH] video: ipu_common: fix build error

[Peng Fan]

Some toolchains fail to build
"clk->rate = (u64)(clk->parent->rate * 16) / div;"
And the cast usage is wrong.

Use the following code to fix the issue,
"
  do_div(parent_rate, div);
  clk->rate = parent_rate;
"

Reported-by: Peter Robinson <pbrobinson@gmail.com>
Signed-off-by: Peng Fan <van.freenix@gmail.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Tom Rini <trini@konsulko.com>
Cc: Anatolij Gustschin <agust@denx.de>
Cc: Peter Robinson <pbrobinson@gmail.com>
---

Hi Peter,

 Please help test this patch to see whether this fix your issue or not.
 Thanks for pointing out this issue.

Thanks,
Peng.

 drivers/video/ipu_common.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/video/ipu_common.c b/drivers/video/ipu_common.c
index 36d4b23..5676a0f 100644
--- a/drivers/video/ipu_common.c
+++ b/drivers/video/ipu_common.c
@@ -352,7 +352,9 @@ static int ipu_pixel_clk_set_rate(struct clk *clk, unsigned long rate)
 	 */
 	__raw_writel((div / 16) << 16, DI_BS_CLKGEN1(clk->id));
 
-	clk->rate = (u64)(clk->parent->rate * 16) / div;
+	do_div(parent_rate, div);
+
+	clk->rate = parent_rate;
 
 	return 0;
 }
-- 
2.6.2

[U-Boot] [PATCH] video: ipu_common: fix build error

[Tom Rini]

On Thu, Apr 28, 2016 at 10:07:53AM +0800, Peng Fan wrote:

> Some toolchains fail to build
> "clk->rate = (u64)(clk->parent->rate * 16) / div;"
> And the cast usage is wrong.
> 
> Use the following code to fix the issue,
> "
>   do_div(parent_rate, div);
>   clk->rate = parent_rate;
> "
> 
> Reported-by: Peter Robinson <pbrobinson@gmail.com>
> Signed-off-by: Peng Fan <van.freenix@gmail.com>
> Cc: Stefano Babic <sbabic@denx.de>
> Cc: Fabio Estevam <fabio.estevam@nxp.com>
> Cc: Tom Rini <trini@konsulko.com>
> Cc: Anatolij Gustschin <agust@denx.de>
> Cc: Peter Robinson <pbrobinson@gmail.com>

Reviewed-by: Tom Rini <trini@konsulko.com>

-- 
Tom
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[U-Boot] [PATCH] video: ipu_common: fix build error

[Peter Robinson]

On Thu, Apr 28, 2016 at 3:07 AM, Peng Fan <van.freenix@gmail.com> wrote:
> Some toolchains fail to build
> "clk->rate = (u64)(clk->parent->rate * 16) / div;"
> And the cast usage is wrong.
>
> Use the following code to fix the issue,
> "
>   do_div(parent_rate, div);
>   clk->rate = parent_rate;
> "
>
> Reported-by: Peter Robinson <pbrobinson@gmail.com>
> Signed-off-by: Peng Fan <van.freenix@gmail.com>
> Cc: Stefano Babic <sbabic@denx.de>
> Cc: Fabio Estevam <fabio.estevam@nxp.com>
> Cc: Tom Rini <trini@konsulko.com>
> Cc: Anatolij Gustschin <agust@denx.de>
> Cc: Peter Robinson <pbrobinson@gmail.com>
Tested-by: Peter Robinson <pbrobinson@gmail.com>

> ---
>
> Hi Peter,
>
>  Please help test this patch to see whether this fix your issue or not.
>  Thanks for pointing out this issue.

It fixes the build issue, I'll be installing it onto a number of
devices over the next couple of days.

Thanks,
Peter

> Thanks,
> Peng.
>
>  drivers/video/ipu_common.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/video/ipu_common.c b/drivers/video/ipu_common.c
> index 36d4b23..5676a0f 100644
> --- a/drivers/video/ipu_common.c
> +++ b/drivers/video/ipu_common.c
> @@ -352,7 +352,9 @@ static int ipu_pixel_clk_set_rate(struct clk *clk, unsigned long rate)
>          */
>         __raw_writel((div / 16) << 16, DI_BS_CLKGEN1(clk->id));
>
> -       clk->rate = (u64)(clk->parent->rate * 16) / div;
> +       do_div(parent_rate, div);
> +
> +       clk->rate = parent_rate;
>
>         return 0;
>  }
> --
> 2.6.2
>

[U-Boot] [PATCH] video: ipu_common: fix build error

[Stefano Babic]

On 28/04/2016 16:20, Peter Robinson wrote:
> On Thu, Apr 28, 2016 at 3:07 AM, Peng Fan <van.freenix@gmail.com> wrote:
>> Some toolchains fail to build
>> "clk->rate = (u64)(clk->parent->rate * 16) / div;"
>> And the cast usage is wrong.
>>
>> Use the following code to fix the issue,
>> "
>>   do_div(parent_rate, div);
>>   clk->rate = parent_rate;
>> "
>>
>> Reported-by: Peter Robinson <pbrobinson@gmail.com>
>> Signed-off-by: Peng Fan <van.freenix@gmail.com>
>> Cc: Stefano Babic <sbabic@denx.de>
>> Cc: Fabio Estevam <fabio.estevam@nxp.com>
>> Cc: Tom Rini <trini@konsulko.com>
>> Cc: Anatolij Gustschin <agust@denx.de>
>> Cc: Peter Robinson <pbrobinson@gmail.com>
> Tested-by: Peter Robinson <pbrobinson@gmail.com>
> 
>> ---
>>
>> Hi Peter,
>>
>>  Please help test this patch to see whether this fix your issue or not.
>>  Thanks for pointing out this issue.
> 
> It fixes the build issue, I'll be installing it onto a number of
> devices over the next couple of days.
> 
> Thanks,
> Peter
> 
>> Thanks,
>> Peng.
>>
>>  drivers/video/ipu_common.c | 4 +++-
>>  1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/video/ipu_common.c b/drivers/video/ipu_common.c
>> index 36d4b23..5676a0f 100644
>> --- a/drivers/video/ipu_common.c
>> +++ b/drivers/video/ipu_common.c
>> @@ -352,7 +352,9 @@ static int ipu_pixel_clk_set_rate(struct clk *clk, unsigned long rate)
>>          */
>>         __raw_writel((div / 16) << 16, DI_BS_CLKGEN1(clk->id));
>>
>> -       clk->rate = (u64)(clk->parent->rate * 16) / div;
>> +       do_div(parent_rate, div);
>> +
>> +       clk->rate = parent_rate;
>>
>>         return 0;
>>  }
>> --
>> 2.6.2
>>

Applied to u-boot-imx, thanks !

Best regards,
Stefano Babic


-- 
=====================================================================
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-53 Fax: +49-8142-66989-80 Email: sbabic at denx.de
=====================================================================

[U-Boot] [PATCH] video: ipu_common: fix build error

[Anatolij Gustschin]

Hi Stefano,

On Thu, 28 Apr 2016 16:29:43 +0200
Stefano Babic sbabic at denx.de wrote:
...
> Applied to u-boot-imx, thanks !

Thanks!

--
Anatolij

[U-Boot] video: ipu_common: fix build error

[Eric Nelson]

Hi Peng,

Can you tell that I'm hunting a bug in an old version?

I'm seeing a **very** intermittent regression between U-Boot
versions 2015.07 and 2016.05 and happened to spot something
in this patch.

On 04/27/2016 07:07 PM, Peng Fan wrote:
> Some toolchains fail to build
> "clk->rate = (u64)(clk->parent->rate * 16) / div;"
> And the cast usage is wrong.
> 
> Use the following code to fix the issue,
> "
>    do_div(parent_rate, div);
>    clk->rate = parent_rate;
> "
> 
> Reported-by: Peter Robinson <pbrobinson@gmail.com>
> Signed-off-by: Peng Fan <van.freenix@gmail.com>
> Cc: Stefano Babic <sbabic@denx.de>
> Cc: Fabio Estevam <fabio.estevam@nxp.com>
> Cc: Tom Rini <trini@konsulko.com>
> Cc: Anatolij Gustschin <agust@denx.de>
> Cc: Peter Robinson <pbrobinson@gmail.com>
> Reviewed-by: Tom Rini <trini@konsulko.com>
> Tested-by: Peter Robinson <pbrobinson@gmail.com>
> ---
> 
> Hi Peter,
> 
>   Please help test this patch to see whether this fix your issue or not.
>   Thanks for pointing out this issue.
> 
> Thanks,
> Peng.
> 
>   drivers/video/ipu_common.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/video/ipu_common.c b/drivers/video/ipu_common.c
> index 36d4b23..5676a0f 100644
> --- a/drivers/video/ipu_common.c
> +++ b/drivers/video/ipu_common.c
> @@ -352,7 +352,9 @@ static int ipu_pixel_clk_set_rate(struct clk *clk, unsigned long rate)
>   	 */
>   	__raw_writel((div / 16) << 16, DI_BS_CLKGEN1(clk->id));
>   

Did we lose a multiply by 16 in this change?

> -	clk->rate = (u64)(clk->parent->rate * 16) / div;
> +	do_div(parent_rate, div);
> +
> +	clk->rate = parent_rate;
>   
>   	return 0;
>   }
> 

Please advise,


Eric

[U-Boot] video: ipu_common: fix build error

[Peng Fan]

Hi Eric,
On Mon, Sep 04, 2017 at 07:48:56PM -0700, Eric Nelson wrote:
>Hi Peng,
>
>Can you tell that I'm hunting a bug in an old version?
>
>I'm seeing a **very** intermittent regression between U-Boot
>versions 2015.07 and 2016.05 and happened to spot something
>in this patch.
>
>On 04/27/2016 07:07 PM, Peng Fan wrote:
>>Some toolchains fail to build
>>"clk->rate = (u64)(clk->parent->rate * 16) / div;"
>>And the cast usage is wrong.
>>
>>Use the following code to fix the issue,
>>"
>>   do_div(parent_rate, div);
>>   clk->rate = parent_rate;
>>"
>>
>>Reported-by: Peter Robinson <pbrobinson@gmail.com>
>>Signed-off-by: Peng Fan <van.freenix@gmail.com>
>>Cc: Stefano Babic <sbabic@denx.de>
>>Cc: Fabio Estevam <fabio.estevam@nxp.com>
>>Cc: Tom Rini <trini@konsulko.com>
>>Cc: Anatolij Gustschin <agust@denx.de>
>>Cc: Peter Robinson <pbrobinson@gmail.com>
>>Reviewed-by: Tom Rini <trini@konsulko.com>
>>Tested-by: Peter Robinson <pbrobinson@gmail.com>
>>---
>>
>>Hi Peter,
>>
>>  Please help test this patch to see whether this fix your issue or not.
>>  Thanks for pointing out this issue.
>>
>>Thanks,
>>Peng.
>>
>>  drivers/video/ipu_common.c | 4 +++-
>>  1 file changed, 3 insertions(+), 1 deletion(-)
>>
>>diff --git a/drivers/video/ipu_common.c b/drivers/video/ipu_common.c
>>index 36d4b23..5676a0f 100644
>>--- a/drivers/video/ipu_common.c
>>+++ b/drivers/video/ipu_common.c
>>@@ -352,7 +352,9 @@ static int ipu_pixel_clk_set_rate(struct clk *clk, unsigned long rate)
>>  	 */
>>  	__raw_writel((div / 16) << 16, DI_BS_CLKGEN1(clk->id));
>
>Did we lose a multiply by 16 in this change?

We already have "parent_rate = (unsigned long long)clk->parent->rate * 16;"
in this function.

Thanks,
Peng.

>
>>-	clk->rate = (u64)(clk->parent->rate * 16) / div;
>>+	do_div(parent_rate, div);
>>+
>>+	clk->rate = parent_rate;
>>  	return 0;
>>  }
>>
>
>Please advise,
>
>
>Eric

[U-Boot] video: ipu_common: fix build error

[Eric Nelson]

Thanks Peng.

On 09/05/2017 06:16 PM, Peng Fan wrote:
> On Mon, Sep 04, 2017 at 07:48:56PM -0700, Eric Nelson wrote:
>> Hi Peng,
>>
>> Can you tell that I'm hunting a bug in an old version?
>>
>> I'm seeing a **very** intermittent regression between U-Boot
>> versions 2015.07 and 2016.05 and happened to spot something
>> in this patch.
>>
>> On 04/27/2016 07:07 PM, Peng Fan wrote:
>>> Some toolchains fail to build
>>> "clk->rate = (u64)(clk->parent->rate * 16) / div;"
>>> And the cast usage is wrong.
>>>
>>> Use the following code to fix the issue,
>>> "
>>>    do_div(parent_rate, div);
>>>    clk->rate = parent_rate;
>>> "
>>>
>>> Reported-by: Peter Robinson <pbrobinson@gmail.com>
>>> Signed-off-by: Peng Fan <van.freenix@gmail.com>
>>> Cc: Stefano Babic <sbabic@denx.de>
>>> Cc: Fabio Estevam <fabio.estevam@nxp.com>
>>> Cc: Tom Rini <trini@konsulko.com>
>>> Cc: Anatolij Gustschin <agust@denx.de>
>>> Cc: Peter Robinson <pbrobinson@gmail.com>
>>> Reviewed-by: Tom Rini <trini@konsulko.com>
>>> Tested-by: Peter Robinson <pbrobinson@gmail.com>
>>> ---
>>>
>>> Hi Peter,
>>>
>>>   Please help test this patch to see whether this fix your issue or not.
>>>   Thanks for pointing out this issue.
>>>
>>> Thanks,
>>> Peng.
>>>
>>>   drivers/video/ipu_common.c | 4 +++-
>>>   1 file changed, 3 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/video/ipu_common.c b/drivers/video/ipu_common.c
>>> index 36d4b23..5676a0f 100644
>>> --- a/drivers/video/ipu_common.c
>>> +++ b/drivers/video/ipu_common.c
>>> @@ -352,7 +352,9 @@ static int ipu_pixel_clk_set_rate(struct clk *clk, unsigned long rate)
>>>   	 */
>>>   	__raw_writel((div / 16) << 16, DI_BS_CLKGEN1(clk->id));
>>
>> Did we lose a multiply by 16 in this change?
> 
> We already have "parent_rate = (unsigned long long)clk->parent->rate * 16;"
> in this function.
> 

Hmmm. So this patch also fixed a bug, since we previously had
**two** multiply-by-16's:

http://git.denx.de/?p=u-boot.git;a=blob;f=drivers/video/ipu_common.c;hb=3cb4f25cc702db17455583599d0940c81337a17a

Regards,


Eric

[U-Boot] video: ipu_common: fix build error

[Lothar Waßmann]

Hi,

On Wed, 6 Sep 2017 10:34:33 -0700 Eric Nelson wrote:
> Thanks Peng.
> 
> On 09/05/2017 06:16 PM, Peng Fan wrote:
> > On Mon, Sep 04, 2017 at 07:48:56PM -0700, Eric Nelson wrote:
> >> Hi Peng,
> >>
> >> Can you tell that I'm hunting a bug in an old version?
> >>
> >> I'm seeing a **very** intermittent regression between U-Boot
> >> versions 2015.07 and 2016.05 and happened to spot something
> >> in this patch.
> >>
> >> On 04/27/2016 07:07 PM, Peng Fan wrote:
> >>> Some toolchains fail to build
> >>> "clk->rate = (u64)(clk->parent->rate * 16) / div;"
> >>> And the cast usage is wrong.
> >>>
> >>> Use the following code to fix the issue,
> >>> "
> >>>    do_div(parent_rate, div);
> >>>    clk->rate = parent_rate;
> >>> "
> >>>
> >>> Reported-by: Peter Robinson <pbrobinson@gmail.com>
> >>> Signed-off-by: Peng Fan <van.freenix@gmail.com>
> >>> Cc: Stefano Babic <sbabic@denx.de>
> >>> Cc: Fabio Estevam <fabio.estevam@nxp.com>
> >>> Cc: Tom Rini <trini@konsulko.com>
> >>> Cc: Anatolij Gustschin <agust@denx.de>
> >>> Cc: Peter Robinson <pbrobinson@gmail.com>
> >>> Reviewed-by: Tom Rini <trini@konsulko.com>
> >>> Tested-by: Peter Robinson <pbrobinson@gmail.com>
> >>> ---
> >>>
> >>> Hi Peter,
> >>>
> >>>   Please help test this patch to see whether this fix your issue or not.
> >>>   Thanks for pointing out this issue.
> >>>
> >>> Thanks,
> >>> Peng.
> >>>
> >>>   drivers/video/ipu_common.c | 4 +++-
> >>>   1 file changed, 3 insertions(+), 1 deletion(-)
> >>>
> >>> diff --git a/drivers/video/ipu_common.c b/drivers/video/ipu_common.c
> >>> index 36d4b23..5676a0f 100644
> >>> --- a/drivers/video/ipu_common.c
> >>> +++ b/drivers/video/ipu_common.c
> >>> @@ -352,7 +352,9 @@ static int ipu_pixel_clk_set_rate(struct clk *clk, unsigned long rate)
> >>>   	 */
> >>>   	__raw_writel((div / 16) << 16, DI_BS_CLKGEN1(clk->id));
> >>
> >> Did we lose a multiply by 16 in this change?
> > 
> > We already have "parent_rate = (unsigned long long)clk->parent->rate * 16;"
> > in this function.
> > 
> 
> Hmmm. So this patch also fixed a bug, since we previously had
> **two** multiply-by-16's:
>
No! The 'second' multiply by 16 used the clk->parent->rate, not the
'parent_rate' which was multiplied by 16...

| parent_rate = (unsigned long long)clk->parent->rate * 16;
[...]
| clk->rate = (u64)(clk->parent->rate * 16) / div;



Lothar Waßmann

[U-Boot] video: ipu_common: fix build error

[Eric Nelson]

On 09/06/2017 11:01 PM, Lothar Waßmann wrote:
> On Wed, 6 Sep 2017 10:34:33 -0700 Eric Nelson wrote:
>> On 09/05/2017 06:16 PM, Peng Fan wrote:
>>> On Mon, Sep 04, 2017 at 07:48:56PM -0700, Eric Nelson wrote:
>>>> Hi Peng,
>>>>
>>>> Can you tell that I'm hunting a bug in an old version?
>>>>
>>>> I'm seeing a **very** intermittent regression between U-Boot
>>>> versions 2015.07 and 2016.05 and happened to spot something
>>>> in this patch.
>>>>
>>>> On 04/27/2016 07:07 PM, Peng Fan wrote:
>>>>> Some toolchains fail to build
>>>>> "clk->rate = (u64)(clk->parent->rate * 16) / div;"
>>>>> And the cast usage is wrong.
>>>>>
>>>>> Use the following code to fix the issue,
>>>>> "
>>>>>     do_div(parent_rate, div);
>>>>>     clk->rate = parent_rate;
>>>>> "
>>>>>
>>>>> Reported-by: Peter Robinson <pbrobinson@gmail.com>
>>>>> Signed-off-by: Peng Fan <van.freenix@gmail.com>
>>>>> Cc: Stefano Babic <sbabic@denx.de>
>>>>> Cc: Fabio Estevam <fabio.estevam@nxp.com>
>>>>> Cc: Tom Rini <trini@konsulko.com>
>>>>> Cc: Anatolij Gustschin <agust@denx.de>
>>>>> Cc: Peter Robinson <pbrobinson@gmail.com>
>>>>> Reviewed-by: Tom Rini <trini@konsulko.com>
>>>>> Tested-by: Peter Robinson <pbrobinson@gmail.com>
>>>>> ---
>>>>>
>>>>> Hi Peter,
>>>>>
>>>>>    Please help test this patch to see whether this fix your issue or not.
>>>>>    Thanks for pointing out this issue.
>>>>>
>>>>> Thanks,
>>>>> Peng.
>>>>>
>>>>>    drivers/video/ipu_common.c | 4 +++-
>>>>>    1 file changed, 3 insertions(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/drivers/video/ipu_common.c b/drivers/video/ipu_common.c
>>>>> index 36d4b23..5676a0f 100644
>>>>> --- a/drivers/video/ipu_common.c
>>>>> +++ b/drivers/video/ipu_common.c
>>>>> @@ -352,7 +352,9 @@ static int ipu_pixel_clk_set_rate(struct clk *clk, unsigned long rate)
>>>>>    	 */
>>>>>    	__raw_writel((div / 16) << 16, DI_BS_CLKGEN1(clk->id));
>>>>
>>>> Did we lose a multiply by 16 in this change?
>>>
>>> We already have "parent_rate = (unsigned long long)clk->parent->rate * 16;"
>>> in this function.
>>>
>>
>> Hmmm. So this patch also fixed a bug, since we previously had
>> **two** multiply-by-16's:
>>
> No! The 'second' multiply by 16 used the clk->parent->rate, not the
> 'parent_rate' which was multiplied by 16...
> 
> | parent_rate = (unsigned long long)clk->parent->rate * 16;
> [...]
> | clk->rate = (u64)(clk->parent->rate * 16) / div;
> 

Doh! I clearly missed that.

Thanks Lothar.

[U-Boot] video: ipu_common: fix build error

[Eric Nelson]

Hi Peng,

Can you tell that I'm hunting a bug in an old version?

I'm seeing a **very** intermittent regression between U-Boot
versions 2015.07 and 2016.05 and happened to spot something
in this patch.

On 04/27/2016 07:07 PM, Peng Fan wrote:
> Some toolchains fail to build
> "clk->rate = (u64)(clk->parent->rate * 16) / div;"
> And the cast usage is wrong.
> 
> Use the following code to fix the issue,
> "
>    do_div(parent_rate, div);
>    clk->rate = parent_rate;
> "
> 
> Reported-by: Peter Robinson <pbrobinson@gmail.com>
> Signed-off-by: Peng Fan <van.freenix@gmail.com>
> Cc: Stefano Babic <sbabic@denx.de>
> Cc: Fabio Estevam <fabio.estevam@nxp.com>
> Cc: Tom Rini <trini@konsulko.com>
> Cc: Anatolij Gustschin <agust@denx.de>
> Cc: Peter Robinson <pbrobinson@gmail.com>
> Reviewed-by: Tom Rini <trini@konsulko.com>
> Tested-by: Peter Robinson <pbrobinson@gmail.com>
> ---
> 
> Hi Peter,
> 
>   Please help test this patch to see whether this fix your issue or not.
>   Thanks for pointing out this issue.
> 
> Thanks,
> Peng.
> 
>   drivers/video/ipu_common.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/video/ipu_common.c b/drivers/video/ipu_common.c
> index 36d4b23..5676a0f 100644
> --- a/drivers/video/ipu_common.c
> +++ b/drivers/video/ipu_common.c
> @@ -352,7 +352,9 @@ static int ipu_pixel_clk_set_rate(struct clk *clk, unsigned long rate)
>   	 */
>   	__raw_writel((div / 16) << 16, DI_BS_CLKGEN1(clk->id));
>   

Did you intend to lose a multiply by 16 here?

> -	clk->rate = (u64)(clk->parent->rate * 16) / div;
> +	do_div(parent_rate, div);
> +
> +	clk->rate = parent_rate;
>   
>   	return 0;
>   }
> 

Please advise,


Eric

[U-Boot] video: ipu_common: fix build error

[Fabio Estevam]

Hi Eric,

On Mon, Sep 4, 2017 at 11:49 PM, Eric Nelson <eric@nelint.com> wrote:
> Hi Peng,
>
> Can you tell that I'm hunting a bug in an old version?
>
> I'm seeing a **very** intermittent regression between U-Boot
> versions 2015.07 and 2016.05 and happened to spot something
> in this patch.

Just curious: how does the regression manifest itself?

[U-Boot] video: ipu_common: fix build error

[Eric Nelson]

Hi Fabio,

On 09/05/2017 06:33 AM, Fabio Estevam wrote:
> Hi Eric,
> 
> On Mon, Sep 4, 2017 at 11:49 PM, Eric Nelson <eric@nelint.com> wrote:
>> Hi Peng,
>>
>> Can you tell that I'm hunting a bug in an old version?
>>
>> I'm seeing a **very** intermittent regression between U-Boot
>> versions 2015.07 and 2016.05 and happened to spot something
>> in this patch.
> 
> Just curious: how does the regression manifest itself?
> 

With **some** televisions at a client site, on **some** power-on
cycles, the HDMI output under Linux doesn't seem to be generated
properly.

We haven't been able to reproduce it in-house, so testing is
taking a while, and we haven't (yet) determined if the
divisor patch has anything to do with the problem.

We are running on an i.MX6DL, but the IPU clock frequency
change doesn't fix the issue (running at 19.8MHz instead of
26MHz).

All we know at the moment is that version 2015.07 works and
2016.05 fails with essentially no changes to the board files.

We're doing this remotely across time zones with limited access
to failing machine(s), so it may take the rest of the week
before we know for sure.

I'll update the thread when we nail it down.

Regards,


Eric