On Tue, Oct 19, 2021 at 06:19:25AM -0600, Tim Gardner wrote:
> Coverity complains of unsigned compare against 0. There are 2 cases in
> this function:
>
> 1821 itp = (irq_holdoff * 1000) / p->desc->qman_256_cycles_per_ns;
>
> CID 121131 (#1 of 1): Unsigned compared against 0 (NO_EFFECT)
> unsigned_compare: This less-than-zero comparison of an unsigned value is
> never true. itp < 0U.
> 1822 if (itp < 0 || itp > 4096) {
> 1823 max_holdoff = (p->desc->qman_256_cycles_per_ns * 4096) /
> 1000;
> 1824 pr_err("irq_holdoff must be between 0..%dus\n",
> max_holdoff);
> 1825 return -EINVAL;
> 1826 }
> 1827
> unsigned_compare: This less-than-zero comparison of an unsigned value
> is never true. irq_threshold < 0U.
> 1828 if (irq_threshold >= p->dqrr.dqrr_size || irq_threshold < 0) {
> 1829 pr_err("irq_threshold must be between 0..%d\n",
> 1830 p->dqrr.dqrr_size - 1);
> 1831 return -EINVAL;
> 1832 }
>
> Fix this by removing the comparisons altogether as they are incorrect. Zero is
> a possible value in either case. Also fix a minor comment typo and update the
> 2 pr_err() calls to use %u formatting as well as be more precise regarding
> the exact error.
>
> Fixes: ed1d2143fee5 ("soc: fsl: dpio: add support for irq coalescing per
> software portal")
> Cc: Ioana Ciornei <ioana.cior...@nxp.com>
> Cc: Roy Pledge <roy.ple...@nxp.com>
> Cc: Li Yang <leoyang...@nxp.com>
> Cc: linux-ker...@vger.kernel.org
> Cc: linuxppc-dev@lists.ozlabs.org
> Cc: linux-arm-ker...@lists.infradead.org
> Cc: net...@vger.kernel.org
> Signed-off-by: Tim Gardner <tim.gard...@canonical.com>
Tested-by: Ioana Ciornei <ioana.cior...@nxp.com>
Reviewed-by: Ioana Ciornei <ioana.cior...@nxp.com>
Thanks,
-Ioana
