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.