Re: [PATCH] clk: Fix a missing check on regmap_bulk_read

From: Stephen Boyd
Date: Wed Jan 09 2019 - 13:55:45 EST


Quoting Aditya Pakki (2018-12-24 11:00:32)
> Currently, vc5_pll_recalc_rate() may produce incorrect output when
> regmap_bulk_read() fails. The fix checks the return value of the
> latter function and returns 0 in case of failure.
>
> Signed-off-by: Aditya Pakki <pakki001@xxxxxxx>
> ---
> drivers/clk/clk-versaclock5.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/clk/clk-versaclock5.c b/drivers/clk/clk-versaclock5.c
> index decffb3826ec..cd76a893c594 100644
> --- a/drivers/clk/clk-versaclock5.c
> +++ b/drivers/clk/clk-versaclock5.c
> @@ -413,7 +413,8 @@ static unsigned long vc5_pll_recalc_rate(struct clk_hw *hw,
> u32 div_int, div_frc;
> u8 fb[5];
>
> - regmap_bulk_read(vc5->regmap, VC5_FEEDBACK_INT_DIV, fb, 5);
> + if (regmap_bulk_read(vc5->regmap, VC5_FEEDBACK_INT_DIV, fb, 5))
> + return 0;

There are a bunch of other regmap_*() APIs in here that "could fail".
Why has this one been chosen but the other ones not?