* Re: [PATCH 1/3] pwm: driver for qualcomm ipq6018 pwm block [not found] <17dd231f496d09ed8502bdd505eaa77bb6637e4b.1644226245.git.baruch@tkos.co.il> @ 2022-02-07 20:22 ` kernel test robot 2022-02-08 6:51 ` Baruch Siach 0 siblings, 1 reply; 3+ messages in thread From: kernel test robot @ 2022-02-07 20:22 UTC (permalink / raw) To: Baruch Siach, Thierry Reding, Uwe Kleine-König, Andy Gross, Bjorn Andersson Cc: llvm, kbuild-all, Baruch Siach, Balaji Prakash J, Rob Herring, Robert Marko, Kathiravan T, linux-pwm Hi Baruch, I love your patch! Perhaps something to improve: [auto build test WARNING on thierry-reding-pwm/for-next] [also build test WARNING on robh/for-next v5.17-rc3 next-20220207] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Baruch-Siach/pwm-driver-for-qualcomm-ipq6018-pwm-block/20220207-175605 base: https://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm.git for-next config: hexagon-allyesconfig (https://download.01.org/0day-ci/archive/20220208/202202080410.R0qwqtXx-lkp@intel.com/config) compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 0d8850ae2cae85d49bea6ae0799fa41c7202c05c) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://github.com/0day-ci/linux/commit/71e449eb6d19b141b4527caae529e16c52bcfeea git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Baruch-Siach/pwm-driver-for-qualcomm-ipq6018-pwm-block/20220207-175605 git checkout 71e449eb6d19b141b4527caae529e16c52bcfeea # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash drivers/pwm/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@intel.com> All warnings (new ones prefixed by >>): >> drivers/pwm/pwm-ipq.c:122:11: warning: result of comparison of constant 16000000000 with expression of type 'unsigned long' is always false [-Wtautological-constant-out-of-range-compare] if (rate > 16ULL * GIGA) ~~~~ ^ ~~~~~~~~~~~~ 1 warning generated. vim +122 drivers/pwm/pwm-ipq.c 99 100 static int ipq_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, 101 const struct pwm_state *state) 102 { 103 struct ipq_pwm_chip *ipq_chip = ipq_pwm_from_chip(chip); 104 unsigned int pre_div, pwm_div, best_pre_div, best_pwm_div; 105 unsigned long rate = clk_get_rate(ipq_chip->clk); 106 u64 period_ns, duty_ns, period_rate; 107 u64 min_diff; 108 109 if (state->polarity != PWM_POLARITY_NORMAL) 110 return -EINVAL; 111 112 if (state->period < DIV64_U64_ROUND_UP(NSEC_PER_SEC, rate)) 113 return -ERANGE; 114 115 period_ns = min(state->period, IPQ_PWM_MAX_PERIOD_NS); 116 duty_ns = min(state->duty_cycle, period_ns); 117 118 /* 119 * period_ns is 1G or less. As long as rate is less than 16 GHz, 120 * period_rate does not overflow. Make that explicit. 121 */ > 122 if (rate > 16ULL * GIGA) 123 return -EINVAL; 124 period_rate = period_ns * rate; 125 best_pre_div = IPQ_PWM_MAX_DIV; 126 best_pwm_div = IPQ_PWM_MAX_DIV; 127 /* 128 * We don't need to consider pre_div values smaller than 129 * 130 * period_rate 131 * pre_div_min := ------------------------------------ 132 * NSEC_PER_SEC * (IPQ_PWM_MAX_DIV + 1) 133 * 134 * because pre_div = pre_div_min results in a better 135 * approximation. 136 */ 137 pre_div = div64_u64(period_rate, 138 (u64)NSEC_PER_SEC * (IPQ_PWM_MAX_DIV + 1)); 139 min_diff = period_rate; 140 141 for (; pre_div <= IPQ_PWM_MAX_DIV; pre_div++) { 142 u64 remainder; 143 144 pwm_div = div64_u64_rem(period_rate, 145 (u64)NSEC_PER_SEC * (pre_div + 1), &remainder); 146 /* pwm_div is unsigned; the check below catches underflow */ 147 pwm_div--; 148 149 /* 150 * Swapping values for pre_div and pwm_div produces the same 151 * period length. So we can skip all settings with pre_div > 152 * pwm_div which results in bigger constraints for selecting 153 * the duty_cycle than with the two values swapped. 154 */ 155 if (pre_div > pwm_div) 156 break; 157 158 /* 159 * Make sure we can do 100% duty cycle where 160 * hi_dur == pwm_div + 1 161 */ 162 if (pwm_div > IPQ_PWM_MAX_DIV - 1) 163 continue; 164 165 if (remainder < min_diff) { 166 best_pre_div = pre_div; 167 best_pwm_div = pwm_div; 168 min_diff = remainder; 169 170 if (min_diff == 0) /* bingo */ 171 break; 172 } 173 } 174 175 /* config divider values for the closest possible frequency */ 176 config_div_and_duty(pwm, best_pre_div, best_pwm_div, 177 rate, duty_ns, state->enabled); 178 179 return 0; 180 } 181 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH 1/3] pwm: driver for qualcomm ipq6018 pwm block 2022-02-07 20:22 ` [PATCH 1/3] pwm: driver for qualcomm ipq6018 pwm block kernel test robot @ 2022-02-08 6:51 ` Baruch Siach 2022-02-08 18:47 ` Nathan Chancellor 0 siblings, 1 reply; 3+ messages in thread From: Baruch Siach @ 2022-02-08 6:51 UTC (permalink / raw) To: kernel test robot Cc: Thierry Reding, Uwe Kleine-König, Andy Gross, Bjorn Andersson, llvm, kbuild-all, Balaji Prakash J, Rob Herring, Robert Marko, Kathiravan T, linux-pwm Hi test robot, Thanks for testing and reporting. On Tue, Feb 08 2022, kernel test robot wrote: [snip] >>> drivers/pwm/pwm-ipq.c:122:11: warning: result of comparison of constant 16000000000 with expression of type 'unsigned long' is always false [-Wtautological-constant-out-of-range-compare] > if (rate > 16ULL * GIGA) > ~~~~ ^ ~~~~~~~~~~~~ > 1 warning generated. This clang warning is only enabled with W=1 (see commit afe956c577b). Not sure how to avoid it. Is there a way to express this condition without making clang warn on platforms where ULONG_MAX == 2^32? Maybe cast to unsigned long long? Or should we just ignore this W=1 warning? baruch > vim +122 drivers/pwm/pwm-ipq.c > > 99 > 100 static int ipq_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, > 101 const struct pwm_state *state) > 102 { > 103 struct ipq_pwm_chip *ipq_chip = ipq_pwm_from_chip(chip); > 104 unsigned int pre_div, pwm_div, best_pre_div, best_pwm_div; > 105 unsigned long rate = clk_get_rate(ipq_chip->clk); > 106 u64 period_ns, duty_ns, period_rate; > 107 u64 min_diff; > 108 > 109 if (state->polarity != PWM_POLARITY_NORMAL) > 110 return -EINVAL; > 111 > 112 if (state->period < DIV64_U64_ROUND_UP(NSEC_PER_SEC, rate)) > 113 return -ERANGE; > 114 > 115 period_ns = min(state->period, IPQ_PWM_MAX_PERIOD_NS); > 116 duty_ns = min(state->duty_cycle, period_ns); > 117 > 118 /* > 119 * period_ns is 1G or less. As long as rate is less than 16 GHz, > 120 * period_rate does not overflow. Make that explicit. > 121 */ > > 122 if (rate > 16ULL * GIGA) > 123 return -EINVAL; > 124 period_rate = period_ns * rate; > 125 best_pre_div = IPQ_PWM_MAX_DIV; > 126 best_pwm_div = IPQ_PWM_MAX_DIV; > 127 /* > 128 * We don't need to consider pre_div values smaller than > 129 * > 130 * period_rate > 131 * pre_div_min := ------------------------------------ > 132 * NSEC_PER_SEC * (IPQ_PWM_MAX_DIV + 1) > 133 * > 134 * because pre_div = pre_div_min results in a better > 135 * approximation. > 136 */ > 137 pre_div = div64_u64(period_rate, > 138 (u64)NSEC_PER_SEC * (IPQ_PWM_MAX_DIV + 1)); > 139 min_diff = period_rate; > 140 > 141 for (; pre_div <= IPQ_PWM_MAX_DIV; pre_div++) { > 142 u64 remainder; > 143 > 144 pwm_div = div64_u64_rem(period_rate, > 145 (u64)NSEC_PER_SEC * (pre_div + 1), &remainder); > 146 /* pwm_div is unsigned; the check below catches underflow */ > 147 pwm_div--; > 148 > 149 /* > 150 * Swapping values for pre_div and pwm_div produces the same > 151 * period length. So we can skip all settings with pre_div > > 152 * pwm_div which results in bigger constraints for selecting > 153 * the duty_cycle than with the two values swapped. > 154 */ > 155 if (pre_div > pwm_div) > 156 break; > 157 > 158 /* > 159 * Make sure we can do 100% duty cycle where > 160 * hi_dur == pwm_div + 1 > 161 */ > 162 if (pwm_div > IPQ_PWM_MAX_DIV - 1) > 163 continue; > 164 > 165 if (remainder < min_diff) { > 166 best_pre_div = pre_div; > 167 best_pwm_div = pwm_div; > 168 min_diff = remainder; > 169 > 170 if (min_diff == 0) /* bingo */ > 171 break; > 172 } > 173 } > 174 > 175 /* config divider values for the closest possible frequency */ > 176 config_div_and_duty(pwm, best_pre_div, best_pwm_div, > 177 rate, duty_ns, state->enabled); > 178 > 179 return 0; > 180 } > 181 > > --- > 0-DAY CI Kernel Test Service, Intel Corporation > https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org -- ~. .~ Tk Open Systems =}------------------------------------------------ooO--U--Ooo------------{= - baruch@tkos.co.il - tel: +972.52.368.4656, http://www.tkos.co.il - ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH 1/3] pwm: driver for qualcomm ipq6018 pwm block 2022-02-08 6:51 ` Baruch Siach @ 2022-02-08 18:47 ` Nathan Chancellor 0 siblings, 0 replies; 3+ messages in thread From: Nathan Chancellor @ 2022-02-08 18:47 UTC (permalink / raw) To: Baruch Siach Cc: kernel test robot, Thierry Reding, Uwe Kleine-König, Andy Gross, Bjorn Andersson, llvm, kbuild-all, Balaji Prakash J, Rob Herring, Robert Marko, Kathiravan T, linux-pwm Hi Baruch, On Tue, Feb 08, 2022 at 08:51:40AM +0200, Baruch Siach wrote: > Hi test robot, > > Thanks for testing and reporting. > > On Tue, Feb 08 2022, kernel test robot wrote: > > [snip] > > >>> drivers/pwm/pwm-ipq.c:122:11: warning: result of comparison of constant 16000000000 with expression of type 'unsigned long' is always false [-Wtautological-constant-out-of-range-compare] > > if (rate > 16ULL * GIGA) > > ~~~~ ^ ~~~~~~~~~~~~ > > 1 warning generated. > > This clang warning is only enabled with W=1 (see commit > afe956c577b). Not sure how to avoid it. > > Is there a way to express this condition without making clang warn on > platforms where ULONG_MAX == 2^32? Maybe cast to unsigned long long? Or > should we just ignore this W=1 warning? As far as I am aware, casting to unsigned long long would be an appropriate way to fix this warning, as has been done in the following patches in mainline: c9ae8eed4463 ("media: omap3isp: avoid warnings at IS_OUT_OF_BOUNDS()") 4853396f03c3 ("memstick: avoid out-of-range warning") 7ff4034e910f ("staging: vc04_services: shut up out-of-range warning") a2fa9e57a68c ("ARM: mvebu: avoid clang -Wtautological-constant warning") The below diff fixes the warning for me with ARCH=hexagon allyesconfig: diff --git a/drivers/pwm/pwm-ipq.c b/drivers/pwm/pwm-ipq.c index 994027290bcb..7ea29468e76e 100644 --- a/drivers/pwm/pwm-ipq.c +++ b/drivers/pwm/pwm-ipq.c @@ -119,7 +119,7 @@ static int ipq_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, * period_ns is 1G or less. As long as rate is less than 16 GHz, * period_rate does not overflow. Make that explicit. */ - if (rate > 16ULL * GIGA) + if ((unsigned long long)rate > 16ULL * GIGA) return -EINVAL; period_rate = period_ns * rate; best_pre_div = IPQ_PWM_MAX_DIV; Alternatively, you could widen rate to unsigned long long / u64 but I don't know what kind of implications that has in this function but it has been done in other places: 95c58291ee70 ("drm/msm/submit: fix overflow check on 64-bit architectures") cfd6fb45cfaf ("crypto: ccree - avoid out-of-range warnings from clang") 335aea75b0d9 ("drm/amdgpu: fix warning for overflow check") 844b85dda2f5 ("ARM: keystone: fix integer overflow warning") While the warning is currently under W=1, I think it is one that we would like to turn on at some point so fixing instances as they come up helps us get closer to that goal. Cheers, Nathan > > vim +122 drivers/pwm/pwm-ipq.c > > > > 99 > > 100 static int ipq_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, > > 101 const struct pwm_state *state) > > 102 { > > 103 struct ipq_pwm_chip *ipq_chip = ipq_pwm_from_chip(chip); > > 104 unsigned int pre_div, pwm_div, best_pre_div, best_pwm_div; > > 105 unsigned long rate = clk_get_rate(ipq_chip->clk); > > 106 u64 period_ns, duty_ns, period_rate; > > 107 u64 min_diff; > > 108 > > 109 if (state->polarity != PWM_POLARITY_NORMAL) > > 110 return -EINVAL; > > 111 > > 112 if (state->period < DIV64_U64_ROUND_UP(NSEC_PER_SEC, rate)) > > 113 return -ERANGE; > > 114 > > 115 period_ns = min(state->period, IPQ_PWM_MAX_PERIOD_NS); > > 116 duty_ns = min(state->duty_cycle, period_ns); > > 117 > > 118 /* > > 119 * period_ns is 1G or less. As long as rate is less than 16 GHz, > > 120 * period_rate does not overflow. Make that explicit. > > 121 */ > > > 122 if (rate > 16ULL * GIGA) > > 123 return -EINVAL; > > 124 period_rate = period_ns * rate; > > 125 best_pre_div = IPQ_PWM_MAX_DIV; > > 126 best_pwm_div = IPQ_PWM_MAX_DIV; > > 127 /* > > 128 * We don't need to consider pre_div values smaller than > > 129 * > > 130 * period_rate > > 131 * pre_div_min := ------------------------------------ > > 132 * NSEC_PER_SEC * (IPQ_PWM_MAX_DIV + 1) > > 133 * > > 134 * because pre_div = pre_div_min results in a better > > 135 * approximation. > > 136 */ > > 137 pre_div = div64_u64(period_rate, > > 138 (u64)NSEC_PER_SEC * (IPQ_PWM_MAX_DIV + 1)); > > 139 min_diff = period_rate; > > 140 > > 141 for (; pre_div <= IPQ_PWM_MAX_DIV; pre_div++) { > > 142 u64 remainder; > > 143 > > 144 pwm_div = div64_u64_rem(period_rate, > > 145 (u64)NSEC_PER_SEC * (pre_div + 1), &remainder); > > 146 /* pwm_div is unsigned; the check below catches underflow */ > > 147 pwm_div--; > > 148 > > 149 /* > > 150 * Swapping values for pre_div and pwm_div produces the same > > 151 * period length. So we can skip all settings with pre_div > > > 152 * pwm_div which results in bigger constraints for selecting > > 153 * the duty_cycle than with the two values swapped. > > 154 */ > > 155 if (pre_div > pwm_div) > > 156 break; > > 157 > > 158 /* > > 159 * Make sure we can do 100% duty cycle where > > 160 * hi_dur == pwm_div + 1 > > 161 */ > > 162 if (pwm_div > IPQ_PWM_MAX_DIV - 1) > > 163 continue; > > 164 > > 165 if (remainder < min_diff) { > > 166 best_pre_div = pre_div; > > 167 best_pwm_div = pwm_div; > > 168 min_diff = remainder; > > 169 > > 170 if (min_diff == 0) /* bingo */ > > 171 break; > > 172 } > > 173 } > > 174 > > 175 /* config divider values for the closest possible frequency */ > > 176 config_div_and_duty(pwm, best_pre_div, best_pwm_div, > > 177 rate, duty_ns, state->enabled); > > 178 > > 179 return 0; > > 180 } > > 181 > > > > --- > > 0-DAY CI Kernel Test Service, Intel Corporation > > https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org > > > -- > ~. .~ Tk Open Systems > =}------------------------------------------------ooO--U--Ooo------------{= > - baruch@tkos.co.il - tel: +972.52.368.4656, http://www.tkos.co.il - > ^ permalink raw reply related [flat|nested] 3+ messages in thread
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2022-02-07 20:22 ` [PATCH 1/3] pwm: driver for qualcomm ipq6018 pwm block kernel test robot
2022-02-08 6:51 ` Baruch Siach
2022-02-08 18:47 ` Nathan Chancellor
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