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SubjectRe: [PATCH V6 XRT Alveo 16/20] fpga: xrt: clock driver
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> +
> +static int get_freq(struct clock *clock, u16 *freq)
> +{

> +
> + /*
> + * Multiply both numerator (mul0) and the denominator (div1) with
> + * 1000 to account for fractional portion of divider
> + */
> +
> + div1 *= 1000;
> + div1 += div_frac1;
> + div0 *= div1;
> + mul0 *= 1000;
> + if (div0 == 0) {
> + CLOCK_ERR(clock, "clockwiz 0 divider");

This prevents a divide by zero, but returns 0 without setting freq

A -EINVAL should be returned or freq initialized to some default value

> + return 0;
> + }
> +
> + input = mul0 * 100;
> + do_div(input, div0);
> + *freq = (u16)input;
> +
> + return 0;
> +}
> +
>
> +
> +static int clock_verify_freq(struct clock *clock)
> +{
> + u32 lookup_freq, clock_freq_counter, request_in_khz, tolerance;
> + int err = 0;
> + u16 freq;
> +
> + mutex_lock(&clock->clock_lock);
> +
> + err = get_freq(clock, &freq);
> + if (err) {
> + xrt_err(clock->xdev, "get freq failed, %d", err);
> + goto end;
> + }
> +
> + err = get_freq_counter(clock, &clock_freq_counter);
> + if (err) {
> + xrt_err(clock->xdev, "get freq counter failed, %d", err);
> + goto end;
> + }
> +
> + lookup_freq = find_matching_freq(freq, frequency_table,
> + ARRAY_SIZE(frequency_table));

I am running v6 through clang's static analyzer, it shows a problem here

drivers/fpga/xrt/lib/xleaf/clock.c:474:16: warning: 1st function call
argument is an uninitialized value
        lookup_freq = find_matching_freq(freq, frequency_table,
                      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

See problem with get_freq above

Tom


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