* Re: drivers/staging/rtlwifi/base.c:920:7-9: WARNING: possible condition with no effect (if == else) [not found] <201710132012.kptCgENA%fengguang.wu@intel.com> @ 2017-10-13 13:55 ` Julia Lawall 2017-10-13 18:11 ` Larry Finger 0 siblings, 1 reply; 3+ messages in thread From: Julia Lawall @ 2017-10-13 13:55 UTC (permalink / raw) To: Larry Finger; +Cc: linux-kernel, Greg Kroah-Hartman, kbuild-all It seems that the then and else branches of the conditions on lines 920 and 932 are the same. julia On Fri, 13 Oct 2017, kbuild test robot wrote: > CC: kbuild-all@01.org > CC: linux-kernel@vger.kernel.org > TO: Larry Finger <Larry.Finger@lwfinger.net> > CC: "Greg Kroah-Hartman" <gregkh@linuxfoundation.org> > > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master > head: 3d7882769b5dc929690f96e0c318c29b97f51018 > commit: 5b5ab4cb5cda824ef59e0511ac5d585f35f1a1a6 staging: r8822be: Add Makefiles and Kconfig for new driver > date: 8 weeks ago > :::::: branch date: 12 hours ago > :::::: commit date: 8 weeks ago > > >> drivers/staging/rtlwifi/base.c:920:7-9: WARNING: possible condition with no effect (if == else) > drivers/staging/rtlwifi/base.c:932:7-9: WARNING: possible condition with no effect (if == else) > > # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5b5ab4cb5cda824ef59e0511ac5d585f35f1a1a6 > git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git > git remote update linus > git checkout 5b5ab4cb5cda824ef59e0511ac5d585f35f1a1a6 > vim +920 drivers/staging/rtlwifi/base.c > > 56bde846 Ping-Ke Shih 2017-08-17 905 > 56bde846 Ping-Ke Shih 2017-08-17 906 static u8 _rtl_get_vht_highest_n_rate(struct ieee80211_hw *hw, > 56bde846 Ping-Ke Shih 2017-08-17 907 struct ieee80211_sta *sta) > 56bde846 Ping-Ke Shih 2017-08-17 908 { > 56bde846 Ping-Ke Shih 2017-08-17 909 struct rtl_priv *rtlpriv = rtl_priv(hw); > 56bde846 Ping-Ke Shih 2017-08-17 910 struct rtl_phy *rtlphy = &rtlpriv->phy; > 56bde846 Ping-Ke Shih 2017-08-17 911 u8 hw_rate; > 56bde846 Ping-Ke Shih 2017-08-17 912 u16 tx_mcs_map = le16_to_cpu(sta->vht_cap.vht_mcs.tx_mcs_map); > 56bde846 Ping-Ke Shih 2017-08-17 913 > 56bde846 Ping-Ke Shih 2017-08-17 914 if ((get_rf_type(rtlphy) == RF_2T2R) && > 56bde846 Ping-Ke Shih 2017-08-17 915 (tx_mcs_map & 0x000c) != 0x000c) { > 56bde846 Ping-Ke Shih 2017-08-17 916 if ((tx_mcs_map & 0x000c) >> 2 == > 56bde846 Ping-Ke Shih 2017-08-17 917 IEEE80211_VHT_MCS_SUPPORT_0_7) > 56bde846 Ping-Ke Shih 2017-08-17 918 hw_rate = > 56bde846 Ping-Ke Shih 2017-08-17 919 rtlpriv->cfg->maps[RTL_RC_VHT_RATE_2SS_MCS7]; > 56bde846 Ping-Ke Shih 2017-08-17 @920 else if ((tx_mcs_map & 0x000c) >> 2 == > 56bde846 Ping-Ke Shih 2017-08-17 921 IEEE80211_VHT_MCS_SUPPORT_0_8) > 56bde846 Ping-Ke Shih 2017-08-17 922 hw_rate = > 56bde846 Ping-Ke Shih 2017-08-17 923 rtlpriv->cfg->maps[RTL_RC_VHT_RATE_2SS_MCS9]; > 56bde846 Ping-Ke Shih 2017-08-17 924 else > 56bde846 Ping-Ke Shih 2017-08-17 925 hw_rate = > 56bde846 Ping-Ke Shih 2017-08-17 926 rtlpriv->cfg->maps[RTL_RC_VHT_RATE_2SS_MCS9]; > 56bde846 Ping-Ke Shih 2017-08-17 927 } else { > 56bde846 Ping-Ke Shih 2017-08-17 928 if ((tx_mcs_map & 0x0003) == > 56bde846 Ping-Ke Shih 2017-08-17 929 IEEE80211_VHT_MCS_SUPPORT_0_7) > 56bde846 Ping-Ke Shih 2017-08-17 930 hw_rate = > 56bde846 Ping-Ke Shih 2017-08-17 931 rtlpriv->cfg->maps[RTL_RC_VHT_RATE_1SS_MCS7]; > 56bde846 Ping-Ke Shih 2017-08-17 932 else if ((tx_mcs_map & 0x0003) == > 56bde846 Ping-Ke Shih 2017-08-17 933 IEEE80211_VHT_MCS_SUPPORT_0_8) > 56bde846 Ping-Ke Shih 2017-08-17 934 hw_rate = > 56bde846 Ping-Ke Shih 2017-08-17 935 rtlpriv->cfg->maps[RTL_RC_VHT_RATE_1SS_MCS9]; > 56bde846 Ping-Ke Shih 2017-08-17 936 else > 56bde846 Ping-Ke Shih 2017-08-17 937 hw_rate = > 56bde846 Ping-Ke Shih 2017-08-17 938 rtlpriv->cfg->maps[RTL_RC_VHT_RATE_1SS_MCS9]; > 56bde846 Ping-Ke Shih 2017-08-17 939 } > 56bde846 Ping-Ke Shih 2017-08-17 940 > 56bde846 Ping-Ke Shih 2017-08-17 941 return hw_rate; > 56bde846 Ping-Ke Shih 2017-08-17 942 } > 56bde846 Ping-Ke Shih 2017-08-17 943 > > :::::: The code at line 920 was first introduced by commit > :::::: 56bde846304ea05d5f8c8de0e3a42627a7a92be6 staging: r8822be: Add existing rtlwifi and rtl_pci parts for new driver > > :::::: TO: Ping-Ke Shih <pkshih@realtek.com> > :::::: CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > > --- > 0-DAY kernel test infrastructure Open Source Technology Center > https://lists.01.org/pipermail/kbuild-all Intel Corporation > ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: drivers/staging/rtlwifi/base.c:920:7-9: WARNING: possible condition with no effect (if == else) 2017-10-13 13:55 ` drivers/staging/rtlwifi/base.c:920:7-9: WARNING: possible condition with no effect (if == else) Julia Lawall @ 2017-10-13 18:11 ` Larry Finger 2017-10-13 21:48 ` Julia Lawall 0 siblings, 1 reply; 3+ messages in thread From: Larry Finger @ 2017-10-13 18:11 UTC (permalink / raw) To: Julia Lawall; +Cc: linux-kernel, Greg Kroah-Hartman, kbuild-all Julia, On 10/13/2017 08:55 AM, Julia Lawall wrote: > It seems that the then and else branches of the conditions on lines 920 > and 932 are the same. I think line 923 should be using RTL_RC_VHT_RATE_2SS_MCS8 rather than RTL_RC_VHT_RATE_2SS_MCS9, but I have sent an inquiry to my contact at Realtek to check. Thanks, Larry > On Fri, 13 Oct 2017, kbuild test robot wrote: > >> CC: kbuild-all@01.org >> CC: linux-kernel@vger.kernel.org >> TO: Larry Finger <Larry.Finger@lwfinger.net> >> CC: "Greg Kroah-Hartman" <gregkh@linuxfoundation.org> >> >> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master >> head: 3d7882769b5dc929690f96e0c318c29b97f51018 >> commit: 5b5ab4cb5cda824ef59e0511ac5d585f35f1a1a6 staging: r8822be: Add Makefiles and Kconfig for new driver >> date: 8 weeks ago >> :::::: branch date: 12 hours ago >> :::::: commit date: 8 weeks ago >> >>>> drivers/staging/rtlwifi/base.c:920:7-9: WARNING: possible condition with no effect (if == else) >> drivers/staging/rtlwifi/base.c:932:7-9: WARNING: possible condition with no effect (if == else) >> >> # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5b5ab4cb5cda824ef59e0511ac5d585f35f1a1a6 >> git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git >> git remote update linus >> git checkout 5b5ab4cb5cda824ef59e0511ac5d585f35f1a1a6 >> vim +920 drivers/staging/rtlwifi/base.c >> >> 56bde846 Ping-Ke Shih 2017-08-17 905 >> 56bde846 Ping-Ke Shih 2017-08-17 906 static u8 _rtl_get_vht_highest_n_rate(struct ieee80211_hw *hw, >> 56bde846 Ping-Ke Shih 2017-08-17 907 struct ieee80211_sta *sta) >> 56bde846 Ping-Ke Shih 2017-08-17 908 { >> 56bde846 Ping-Ke Shih 2017-08-17 909 struct rtl_priv *rtlpriv = rtl_priv(hw); >> 56bde846 Ping-Ke Shih 2017-08-17 910 struct rtl_phy *rtlphy = &rtlpriv->phy; >> 56bde846 Ping-Ke Shih 2017-08-17 911 u8 hw_rate; >> 56bde846 Ping-Ke Shih 2017-08-17 912 u16 tx_mcs_map = le16_to_cpu(sta->vht_cap.vht_mcs.tx_mcs_map); >> 56bde846 Ping-Ke Shih 2017-08-17 913 >> 56bde846 Ping-Ke Shih 2017-08-17 914 if ((get_rf_type(rtlphy) == RF_2T2R) && >> 56bde846 Ping-Ke Shih 2017-08-17 915 (tx_mcs_map & 0x000c) != 0x000c) { >> 56bde846 Ping-Ke Shih 2017-08-17 916 if ((tx_mcs_map & 0x000c) >> 2 == >> 56bde846 Ping-Ke Shih 2017-08-17 917 IEEE80211_VHT_MCS_SUPPORT_0_7) >> 56bde846 Ping-Ke Shih 2017-08-17 918 hw_rate = >> 56bde846 Ping-Ke Shih 2017-08-17 919 rtlpriv->cfg->maps[RTL_RC_VHT_RATE_2SS_MCS7]; >> 56bde846 Ping-Ke Shih 2017-08-17 @920 else if ((tx_mcs_map & 0x000c) >> 2 == >> 56bde846 Ping-Ke Shih 2017-08-17 921 IEEE80211_VHT_MCS_SUPPORT_0_8) >> 56bde846 Ping-Ke Shih 2017-08-17 922 hw_rate = >> 56bde846 Ping-Ke Shih 2017-08-17 923 rtlpriv->cfg->maps[RTL_RC_VHT_RATE_2SS_MCS9]; >> 56bde846 Ping-Ke Shih 2017-08-17 924 else >> 56bde846 Ping-Ke Shih 2017-08-17 925 hw_rate = >> 56bde846 Ping-Ke Shih 2017-08-17 926 rtlpriv->cfg->maps[RTL_RC_VHT_RATE_2SS_MCS9]; >> 56bde846 Ping-Ke Shih 2017-08-17 927 } else { >> 56bde846 Ping-Ke Shih 2017-08-17 928 if ((tx_mcs_map & 0x0003) == >> 56bde846 Ping-Ke Shih 2017-08-17 929 IEEE80211_VHT_MCS_SUPPORT_0_7) >> 56bde846 Ping-Ke Shih 2017-08-17 930 hw_rate = >> 56bde846 Ping-Ke Shih 2017-08-17 931 rtlpriv->cfg->maps[RTL_RC_VHT_RATE_1SS_MCS7]; >> 56bde846 Ping-Ke Shih 2017-08-17 932 else if ((tx_mcs_map & 0x0003) == >> 56bde846 Ping-Ke Shih 2017-08-17 933 IEEE80211_VHT_MCS_SUPPORT_0_8) >> 56bde846 Ping-Ke Shih 2017-08-17 934 hw_rate = >> 56bde846 Ping-Ke Shih 2017-08-17 935 rtlpriv->cfg->maps[RTL_RC_VHT_RATE_1SS_MCS9]; >> 56bde846 Ping-Ke Shih 2017-08-17 936 else >> 56bde846 Ping-Ke Shih 2017-08-17 937 hw_rate = >> 56bde846 Ping-Ke Shih 2017-08-17 938 rtlpriv->cfg->maps[RTL_RC_VHT_RATE_1SS_MCS9]; >> 56bde846 Ping-Ke Shih 2017-08-17 939 } >> 56bde846 Ping-Ke Shih 2017-08-17 940 >> 56bde846 Ping-Ke Shih 2017-08-17 941 return hw_rate; >> 56bde846 Ping-Ke Shih 2017-08-17 942 } >> 56bde846 Ping-Ke Shih 2017-08-17 943 >> >> :::::: The code at line 920 was first introduced by commit >> :::::: 56bde846304ea05d5f8c8de0e3a42627a7a92be6 staging: r8822be: Add existing rtlwifi and rtl_pci parts for new driver >> >> :::::: TO: Ping-Ke Shih <pkshih@realtek.com> >> :::::: CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> >> >> --- >> 0-DAY kernel test infrastructure Open Source Technology Center >> https://lists.01.org/pipermail/kbuild-all Intel Corporation >> > ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: drivers/staging/rtlwifi/base.c:920:7-9: WARNING: possible condition with no effect (if == else) 2017-10-13 18:11 ` Larry Finger @ 2017-10-13 21:48 ` Julia Lawall 0 siblings, 0 replies; 3+ messages in thread From: Julia Lawall @ 2017-10-13 21:48 UTC (permalink / raw) To: Larry Finger; +Cc: linux-kernel, Greg Kroah-Hartman, kbuild-all On Fri, 13 Oct 2017, Larry Finger wrote: > Julia, > > On 10/13/2017 08:55 AM, Julia Lawall wrote: > > It seems that the then and else branches of the conditions on lines 920 > > and 932 are the same. > > I think line 923 should be using RTL_RC_VHT_RATE_2SS_MCS8 rather than > RTL_RC_VHT_RATE_2SS_MCS9, but I have sent an inquiry to my contact at Realtek > to check. OK, thanks. The realtek code has a surprisingly large number of these kinds of problems, for example, the following from (drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtc8723b2ant.c): if ((wifi_rssi_state == BTC_RSSI_STATE_HIGH) || (wifi_rssi_state == BTC_RSSI_STATE_STAY_HIGH)) { btc8723b2ant_sw_mechanism(btcoexist, true, false, false, false); } else { btc8723b2ant_sw_mechanism(btcoexist, true, false, false, false); } I wondered if the code is generated, and the generator has a policy of just doing the last "then" branch if all of the known tests fail. I could send a complete list of such issues, if they are of interest. julia > > Thanks, > > Larry > > > On Fri, 13 Oct 2017, kbuild test robot wrote: > > > > > CC: kbuild-all@01.org > > > CC: linux-kernel@vger.kernel.org > > > TO: Larry Finger <Larry.Finger@lwfinger.net> > > > CC: "Greg Kroah-Hartman" <gregkh@linuxfoundation.org> > > > > > > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git > > > master > > > head: 3d7882769b5dc929690f96e0c318c29b97f51018 > > > commit: 5b5ab4cb5cda824ef59e0511ac5d585f35f1a1a6 staging: r8822be: Add > > > Makefiles and Kconfig for new driver > > > date: 8 weeks ago > > > :::::: branch date: 12 hours ago > > > :::::: commit date: 8 weeks ago > > > > > > > > drivers/staging/rtlwifi/base.c:920:7-9: WARNING: possible condition > > > > > with no effect (if == else) > > > drivers/staging/rtlwifi/base.c:932:7-9: WARNING: possible condition > > > with no effect (if == else) > > > > > > # > > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5b5ab4cb5cda824ef59e0511ac5d585f35f1a1a6 > > > git remote add linus > > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git > > > git remote update linus > > > git checkout 5b5ab4cb5cda824ef59e0511ac5d585f35f1a1a6 > > > vim +920 drivers/staging/rtlwifi/base.c > > > > > > 56bde846 Ping-Ke Shih 2017-08-17 905 > > > 56bde846 Ping-Ke Shih 2017-08-17 906 static u8 > > > _rtl_get_vht_highest_n_rate(struct ieee80211_hw *hw, > > > 56bde846 Ping-Ke Shih 2017-08-17 907 > > > struct ieee80211_sta *sta) > > > 56bde846 Ping-Ke Shih 2017-08-17 908 { > > > 56bde846 Ping-Ke Shih 2017-08-17 909 struct rtl_priv *rtlpriv = > > > rtl_priv(hw); > > > 56bde846 Ping-Ke Shih 2017-08-17 910 struct rtl_phy *rtlphy = > > > &rtlpriv->phy; > > > 56bde846 Ping-Ke Shih 2017-08-17 911 u8 hw_rate; > > > 56bde846 Ping-Ke Shih 2017-08-17 912 u16 tx_mcs_map = > > > le16_to_cpu(sta->vht_cap.vht_mcs.tx_mcs_map); > > > 56bde846 Ping-Ke Shih 2017-08-17 913 > > > 56bde846 Ping-Ke Shih 2017-08-17 914 if ((get_rf_type(rtlphy) == > > > RF_2T2R) && > > > 56bde846 Ping-Ke Shih 2017-08-17 915 (tx_mcs_map & 0x000c) != > > > 0x000c) { > > > 56bde846 Ping-Ke Shih 2017-08-17 916 if ((tx_mcs_map & > > > 0x000c) >> 2 == > > > 56bde846 Ping-Ke Shih 2017-08-17 917 > > > IEEE80211_VHT_MCS_SUPPORT_0_7) > > > 56bde846 Ping-Ke Shih 2017-08-17 918 hw_rate = > > > 56bde846 Ping-Ke Shih 2017-08-17 919 > > > rtlpriv->cfg->maps[RTL_RC_VHT_RATE_2SS_MCS7]; > > > 56bde846 Ping-Ke Shih 2017-08-17 @920 else if ((tx_mcs_map > > > & 0x000c) >> 2 == > > > 56bde846 Ping-Ke Shih 2017-08-17 921 > > > IEEE80211_VHT_MCS_SUPPORT_0_8) > > > 56bde846 Ping-Ke Shih 2017-08-17 922 hw_rate = > > > 56bde846 Ping-Ke Shih 2017-08-17 923 > > > rtlpriv->cfg->maps[RTL_RC_VHT_RATE_2SS_MCS9]; > > > 56bde846 Ping-Ke Shih 2017-08-17 924 else > > > 56bde846 Ping-Ke Shih 2017-08-17 925 hw_rate = > > > 56bde846 Ping-Ke Shih 2017-08-17 926 > > > rtlpriv->cfg->maps[RTL_RC_VHT_RATE_2SS_MCS9]; > > > 56bde846 Ping-Ke Shih 2017-08-17 927 } else { > > > 56bde846 Ping-Ke Shih 2017-08-17 928 if ((tx_mcs_map & > > > 0x0003) == > > > 56bde846 Ping-Ke Shih 2017-08-17 929 > > > IEEE80211_VHT_MCS_SUPPORT_0_7) > > > 56bde846 Ping-Ke Shih 2017-08-17 930 hw_rate = > > > 56bde846 Ping-Ke Shih 2017-08-17 931 > > > rtlpriv->cfg->maps[RTL_RC_VHT_RATE_1SS_MCS7]; > > > 56bde846 Ping-Ke Shih 2017-08-17 932 else if ((tx_mcs_map > > > & 0x0003) == > > > 56bde846 Ping-Ke Shih 2017-08-17 933 > > > IEEE80211_VHT_MCS_SUPPORT_0_8) > > > 56bde846 Ping-Ke Shih 2017-08-17 934 hw_rate = > > > 56bde846 Ping-Ke Shih 2017-08-17 935 > > > rtlpriv->cfg->maps[RTL_RC_VHT_RATE_1SS_MCS9]; > > > 56bde846 Ping-Ke Shih 2017-08-17 936 else > > > 56bde846 Ping-Ke Shih 2017-08-17 937 hw_rate = > > > 56bde846 Ping-Ke Shih 2017-08-17 938 > > > rtlpriv->cfg->maps[RTL_RC_VHT_RATE_1SS_MCS9]; > > > 56bde846 Ping-Ke Shih 2017-08-17 939 } > > > 56bde846 Ping-Ke Shih 2017-08-17 940 > > > 56bde846 Ping-Ke Shih 2017-08-17 941 return hw_rate; > > > 56bde846 Ping-Ke Shih 2017-08-17 942 } > > > 56bde846 Ping-Ke Shih 2017-08-17 943 > > > > > > :::::: The code at line 920 was first introduced by commit > > > :::::: 56bde846304ea05d5f8c8de0e3a42627a7a92be6 staging: r8822be: Add > > > existing rtlwifi and rtl_pci parts for new driver > > > > > > :::::: TO: Ping-Ke Shih <pkshih@realtek.com> > > > :::::: CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > > > > > > --- > > > 0-DAY kernel test infrastructure Open Source Technology > > > Center > > > https://lists.01.org/pipermail/kbuild-all Intel > > > Corporation > > > > > > > ^ permalink raw reply [flat|nested] 3+ messages in thread
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2017-10-13 13:55 ` drivers/staging/rtlwifi/base.c:920:7-9: WARNING: possible condition with no effect (if == else) Julia Lawall
2017-10-13 18:11 ` Larry Finger
2017-10-13 21:48 ` Julia Lawall
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