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that check trips on this pair, notably when building with W=1. >> >> This combination fails to build (e.g. parisc allyesconfig, GCC 15, as >> reported by the 0-day bot). >> >> Use min_t(u32, ilog2(us) + 1U, 7U) so both sides of the comparison are >> unsigned and consistent with aspm_l1_enter_lat. > > Adding 1U (rather than 1) is enough to make everything signed. > Alternatively change the 7U to 7 and it will all be fine regardless of > whether ilog2() returns a signed or unsigned result. > > Remember min_t(u32, x, y) is min((u32)x, (u32)y) and you wouldn't put in > casts like that for any other arithmetic operation. > > Note that for the compile to fail there has to be a code path where > ilog2(us) isn't known to generate a non-negative value. > ilog2(us) (probably) ends up as 'fls(us) - 1'. If that is implemented using a > compiler builtin (because there is a single instruction) then gcc knows that > the input can't be zero (from the max()), so knows that fls() can't return 0 > (which it does for 0), so knows it is never negative and the checks in min() > pass. > > parisc may be one of the architectures that ends up with a real function > for fls() so the compiler doesn't know the result of ilog2() is > non-negative. > > Just delete the U. > > David Thank you David for the review. Hi Bjorn, Mani, Let me know if you are OK with David's suggestion, I will send new patch as shown below - pcie->aspm_l1_enter_lat = min(ilog2(us) + 1, 7U); + pcie->aspm_l1_enter_lat = min(ilog2(us) + 1, 7); > >> >> Fixes: 4a44cd65c9dd ("PCI: tegra194: Use aspm-l1-entry-delay-ns DT property for L1 entrance latency") >> Signed-off-by: Manikanta Maddireddy >> Reported-by: kernel test robot >> Closes: https://lore.kernel.org/oe-kbuild-all/202604051407.AODe3ddZ-lkp@intel.com/ >> --- >> drivers/pci/controller/dwc/pcie-tegra194.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c >> index 393f75ce3df3..93d3452ac117 100644 >> --- a/drivers/pci/controller/dwc/pcie-tegra194.c >> +++ b/drivers/pci/controller/dwc/pcie-tegra194.c >> @@ -1147,7 +1147,7 @@ static int tegra_pcie_dw_parse_dt(struct tegra_pcie_dw *pcie) >> if (!ret) { >> u32 us = max(val / 1000, 1U); >> >> - pcie->aspm_l1_enter_lat = min(ilog2(us) + 1, 7U); >> + pcie->aspm_l1_enter_lat = min_t(u32, ilog2(us) + 1U, 7U); >> } >> >> ret = of_property_read_u32(np, "num-lanes", &pcie->num_lanes); > -- nvpublic