[PATCH] clk: divider: Fix table round up function

[PATCH] clk: divider: Fix table round up function

[Maxime COQUELIN]

Commit 1d9fe6b97 ("clk: divider: Fix best div calculation for power-of-two and
table dividers") introduces a regression in its _table_round_up function.

When the divider passed to this function is greater than the max divider
available in the table, this function returns table's max divider.
Problem is that it causes an infinite loop in clk_divider_bestdiv() because
_next_div() will never return a value greater than maxdiv.

Instead of returning table's max divider, this patch returns INT_MAX.

Reported-by: Fabio Estevam <festevam@gmail.com>
Reported-by: Shawn Guo <shawn.guo@freescale.com>
Tested-by: Fabio Estevam <festevam@gmail.com>
Cc: Mike Turquette <mike.turquette@linaro.org>
Signed-off-by: Maxime Coquelin <maxime.coquelin@st.com>
---
 drivers/clk/clk-divider.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c
index b3c8396..cf9114a 100644
--- a/drivers/clk/clk-divider.c
+++ b/drivers/clk/clk-divider.c
@@ -158,7 +158,7 @@ static bool _is_valid_div(struct clk_divider *divider, unsigned int div)
 static int _round_up_table(const struct clk_div_table *table, int div)
 {
 	const struct clk_div_table *clkt;
-	int up = _get_table_maxdiv(table);
+	int up = INT_MAX;
 
 	for (clkt = table; clkt->div; clkt++) {
 		if (clkt->div == div)
-- 
1.9.1

[PATCH] clk: divider: Fix table round up function

[Shawn Guo]

On Wed, May 07, 2014 at 06:48:52PM +0200, Maxime COQUELIN wrote:
> Commit 1d9fe6b97 ("clk: divider: Fix best div calculation for power-of-two and
> table dividers") introduces a regression in its _table_round_up function.
> 
> When the divider passed to this function is greater than the max divider
> available in the table, this function returns table's max divider.
> Problem is that it causes an infinite loop in clk_divider_bestdiv() because
> _next_div() will never return a value greater than maxdiv.
> 
> Instead of returning table's max divider, this patch returns INT_MAX.
> 
> Reported-by: Fabio Estevam <festevam@gmail.com>
> Reported-by: Shawn Guo <shawn.guo@freescale.com>
> Tested-by: Fabio Estevam <festevam@gmail.com>
> Cc: Mike Turquette <mike.turquette@linaro.org>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@st.com>

Tested-by: Shawn Guo <shawn.guo@freescale.com>

Thanks for the fix.

Shawn

> ---
>  drivers/clk/clk-divider.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c
> index b3c8396..cf9114a 100644
> --- a/drivers/clk/clk-divider.c
> +++ b/drivers/clk/clk-divider.c
> @@ -158,7 +158,7 @@ static bool _is_valid_div(struct clk_divider *divider, unsigned int div)
>  static int _round_up_table(const struct clk_div_table *table, int div)
>  {
>  	const struct clk_div_table *clkt;
> -	int up = _get_table_maxdiv(table);
> +	int up = INT_MAX;
>  
>  	for (clkt = table; clkt->div; clkt++) {
>  		if (clkt->div == div)
> -- 
> 1.9.1
> 

[PATCH] clk: divider: Fix table round up function

[Fabio Estevam]

Hi Mike,

On Wed, May 7, 2014 at 1:48 PM, Maxime COQUELIN <maxime.coquelin@st.com> wrote:
> Commit 1d9fe6b97 ("clk: divider: Fix best div calculation for power-of-two and
> table dividers") introduces a regression in its _table_round_up function.
>
> When the divider passed to this function is greater than the max divider
> available in the table, this function returns table's max divider.
> Problem is that it causes an infinite loop in clk_divider_bestdiv() because
> _next_div() will never return a value greater than maxdiv.
>
> Instead of returning table's max divider, this patch returns INT_MAX.
>
> Reported-by: Fabio Estevam <festevam@gmail.com>
> Reported-by: Shawn Guo <shawn.guo@freescale.com>
> Tested-by: Fabio Estevam <festevam@gmail.com>
> Cc: Mike Turquette <mike.turquette@linaro.org>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@st.com>

Any comments on this one? It does fix a regression.

[PATCH] clk: divider: Fix table round up function

[Maxime Coquelin]

Hi Mike,

On 05/15/2014 03:28 PM, Fabio Estevam wrote:
> Hi Mike,
>
> On Wed, May 7, 2014 at 1:48 PM, Maxime COQUELIN <maxime.coquelin@st.com> wrote:
>> Commit 1d9fe6b97 ("clk: divider: Fix best div calculation for power-of-two and
>> table dividers") introduces a regression in its _table_round_up function.
>>
>> When the divider passed to this function is greater than the max divider
>> available in the table, this function returns table's max divider.
>> Problem is that it causes an infinite loop in clk_divider_bestdiv() because
>> _next_div() will never return a value greater than maxdiv.
>>
>> Instead of returning table's max divider, this patch returns INT_MAX.
>>
>> Reported-by: Fabio Estevam <festevam@gmail.com>
>> Reported-by: Shawn Guo <shawn.guo@freescale.com>
>> Tested-by: Fabio Estevam <festevam@gmail.com>
>> Cc: Mike Turquette <mike.turquette@linaro.org>
>> Signed-off-by: Maxime Coquelin <maxime.coquelin@st.com>
>
> Any comments on this one? It does fix a regression.
>

This patch is important as it fixes a regression, could you review it 
please?

Thanks,
Maxime

[PATCH] clk: divider: Fix table round up function

[Mike Turquette]

Quoting Maxime COQUELIN (2014-05-07 09:48:52)
> Commit 1d9fe6b97 ("clk: divider: Fix best div calculation for power-of-two and
> table dividers") introduces a regression in its _table_round_up function.
> 
> When the divider passed to this function is greater than the max divider
> available in the table, this function returns table's max divider.
> Problem is that it causes an infinite loop in clk_divider_bestdiv() because
> _next_div() will never return a value greater than maxdiv.
> 
> Instead of returning table's max divider, this patch returns INT_MAX.
> 
> Reported-by: Fabio Estevam <festevam@gmail.com>
> Reported-by: Shawn Guo <shawn.guo@freescale.com>
> Tested-by: Fabio Estevam <festevam@gmail.com>
> Cc: Mike Turquette <mike.turquette@linaro.org>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@st.com>

Pulled into clk-fixes for -rc7.

Regards,
Mike

> ---
>  drivers/clk/clk-divider.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c
> index b3c8396..cf9114a 100644
> --- a/drivers/clk/clk-divider.c
> +++ b/drivers/clk/clk-divider.c
> @@ -158,7 +158,7 @@ static bool _is_valid_div(struct clk_divider *divider, unsigned int div)
>  static int _round_up_table(const struct clk_div_table *table, int div)
>  {
>         const struct clk_div_table *clkt;
> -       int up = _get_table_maxdiv(table);
> +       int up = INT_MAX;
>  
>         for (clkt = table; clkt->div; clkt++) {
>                 if (clkt->div == div)
> -- 
> 1.9.1
> 

[PATCH] clk: divider: Fix table round up function

[Maxime Coquelin]

On 05/23/2014 11:39 PM, Mike Turquette wrote:
> Quoting Maxime COQUELIN (2014-05-07 09:48:52)
>> Commit 1d9fe6b97 ("clk: divider: Fix best div calculation for power-of-two and
>> table dividers") introduces a regression in its _table_round_up function.
>>
>> When the divider passed to this function is greater than the max divider
>> available in the table, this function returns table's max divider.
>> Problem is that it causes an infinite loop in clk_divider_bestdiv() because
>> _next_div() will never return a value greater than maxdiv.
>>
>> Instead of returning table's max divider, this patch returns INT_MAX.
>>
>> Reported-by: Fabio Estevam <festevam@gmail.com>
>> Reported-by: Shawn Guo <shawn.guo@freescale.com>
>> Tested-by: Fabio Estevam <festevam@gmail.com>
>> Cc: Mike Turquette <mike.turquette@linaro.org>
>> Signed-off-by: Maxime Coquelin <maxime.coquelin@st.com>
>
> Pulled into clk-fixes for -rc7.

Thanks Mike.

Regards,
Maxime

>
> Regards,
> Mike
>
>> ---
>>   drivers/clk/clk-divider.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c
>> index b3c8396..cf9114a 100644
>> --- a/drivers/clk/clk-divider.c
>> +++ b/drivers/clk/clk-divider.c
>> @@ -158,7 +158,7 @@ static bool _is_valid_div(struct clk_divider *divider, unsigned int div)
>>   static int _round_up_table(const struct clk_div_table *table, int div)
>>   {
>>          const struct clk_div_table *clkt;
>> -       int up = _get_table_maxdiv(table);
>> +       int up = INT_MAX;
>>
>>          for (clkt = table; clkt->div; clkt++) {
>>                  if (clkt->div == div)
>> --
>> 1.9.1
>>