On Mon, Jul 11, 2022 at 3:29 PM Justin Stitt <justinstitt@xxxxxxxxxx> wrote: > > When building with Clang we encounter these warnings: > | drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c:1108:47: error: > | format specifies type 'unsigned char' but the argument has type 's16' > | (aka 'short') [-Werror,-Wformat] IWL_DEBUG_INFO(mvm, "\tburst index: > | %hhu\n", res->ftm.burst_index); > - > | drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c:1111:47: error: > | format specifies type 'unsigned char' but the argument has type 's32' > | (aka 'int') [-Werror,-Wformat] IWL_DEBUG_INFO(mvm, "\trssi spread: > | %hhu\n", res->ftm.rssi_spread); > > The previous format specifier `%hhu` describes a u8 but our arguments > are wider than this which means bits are potentially being lost. > > Variadic functions (printf-like) undergo default argument promotion. > Documentation/core-api/printk-formats.rst specifically recommends using > the promoted-to-type's format flag. > > As per C11 6.3.1.1: > (https://www.open-std.org/jtc1/sc22/wg14/www/docs/n1548.pdf) `If an int > can represent all values of the original type ..., the value is > converted to an int; otherwise, it is converted to an unsigned int. > These are called the integer promotions.` Thus it makes sense to change > `%hhu` to `%d` for both instances of the warning. > > Link: https://github.com/ClangBuiltLinux/linux/issues/378 > Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx> Thanks for the patch! Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> > --- > drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c b/drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c > index 430044bc4755..e8702184c950 100644 > --- a/drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c > +++ b/drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c > @@ -1105,10 +1105,10 @@ static void iwl_mvm_debug_range_resp(struct iwl_mvm *mvm, u8 index, > IWL_DEBUG_INFO(mvm, "\tstatus: %d\n", res->status); > IWL_DEBUG_INFO(mvm, "\tBSSID: %pM\n", res->addr); > IWL_DEBUG_INFO(mvm, "\thost time: %llu\n", res->host_time); > - IWL_DEBUG_INFO(mvm, "\tburst index: %hhu\n", res->ftm.burst_index); > + IWL_DEBUG_INFO(mvm, "\tburst index: %d\n", res->ftm.burst_index); > IWL_DEBUG_INFO(mvm, "\tsuccess num: %u\n", res->ftm.num_ftmr_successes); > IWL_DEBUG_INFO(mvm, "\trssi: %d\n", res->ftm.rssi_avg); > - IWL_DEBUG_INFO(mvm, "\trssi spread: %hhu\n", res->ftm.rssi_spread); > + IWL_DEBUG_INFO(mvm, "\trssi spread: %d\n", res->ftm.rssi_spread); > IWL_DEBUG_INFO(mvm, "\trtt: %lld\n", res->ftm.rtt_avg); > IWL_DEBUG_INFO(mvm, "\trtt var: %llu\n", res->ftm.rtt_variance); > IWL_DEBUG_INFO(mvm, "\trtt spread: %llu\n", res->ftm.rtt_spread); > -- > 2.37.0.144.g8ac04bfd2-goog > -- Thanks, ~Nick Desaulniers
