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