On Wed, May 23, 2018 at 01:03:08PM +0200, Johannes Berg wrote: > On Wed, 2018-03-28 at 12:05 -0700, Alexei Starovoitov wrote: > > fix iwlwifi_dev_ucode_error tracepoint to pass pointer to a table > > instead of all 17 arguments by value. > > dvm/main.c and mvm/utils.c have 'struct iwl_error_event_table' > > defined with very similar yet subtly different fields and offsets. > > tracepoint is still common and using definition of 'struct iwl_error_event_table' > > from dvm/commands.h while copying fields. > > Long term this tracepoint probably should be split into two. > > It would've been nice to CC the wireless list for wireless related > patches ... Ohh. I didn't realize that networking wireless doesn't fall under netdev. I thought wireless folks are silent because they are embarrassed by a function with 17 arguments. > > --- a/drivers/net/wireless/intel/iwlwifi/iwl-devtrace.c > > +++ b/drivers/net/wireless/intel/iwlwifi/iwl-devtrace.c > > @@ -30,6 +30,7 @@ > > #ifndef __CHECKER__ > > #include "iwl-trans.h" > > > > +#include "dvm/commands.h" > > In particular, this breaks the whole driver abstraction. > > > +++ b/drivers/net/wireless/intel/iwlwifi/mvm/utils.c > > @@ -549,12 +549,7 @@ static void iwl_mvm_dump_lmac_error_log(struct iwl_mvm *mvm, u32 base) > > > > IWL_ERR(mvm, "Loaded firmware version: %s\n", mvm->fw->fw_version); > > > > - trace_iwlwifi_dev_ucode_error(trans->dev, table.error_id, table.tsf_low, > > - table.data1, table.data2, table.data3, > > - table.blink2, table.ilink1, > > - table.ilink2, table.bcon_time, table.gp1, > > - table.gp2, table.fw_rev_type, table.major, > > - table.minor, table.hw_ver, table.brd_ver); > > + trace_iwlwifi_dev_ucode_error(trans->dev, &table, table.hw_ver, table.brd_ver); > > This is also utterly wrong because mvm has - for better or worse - a > different type "struct iwl_error_event_table" in this file ... As I was trying to explain in the commit log the single struct is used in both places, but differences in two "struct iwl_error_event_table" are carefully matched field and by field. For two extra fields it was not possible and they are passed separately as you can see above. I still believe that tracepoint output is still exactly the same before and after the patch. I guess you see the breakage because new fields got added into one "struct iwl_error_event_table", but were not added to its evil twin "struct iwl_error_event_table" with the same name after the patch landed ? imo wireless folks need to avoid such naming conflicts. I suggest to isolate common fields into separate base struct and give two children structs different names.
