Re: [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@xxxxxxxxx>
> Reported-by: Shawn Guo <shawn.guo@xxxxxxxxxxxxx>
> Tested-by: Fabio Estevam <festevam@xxxxxxxxx>
> Cc: Mike Turquette <mike.turquette@xxxxxxxxxx>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@xxxxxx>

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

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
> 
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