Hi, dan I forget to explain the reason of changing "pos" to "pos + 2” in the commit message. Thank you for your suggestion. IE is TLV struct, but ht_cap and ht_oper aren’t TLV struct,the origin marvell driver code is wrong. we fix the bug by changing pos(the address of IE) to pos+2 ( the address of IE’s value ). regards, qize wang > 在 2019年11月22日,下午8:37,Dan Carpenter <dan.carpenter@xxxxxxxxxx> 写道: > > On Fri, Nov 22, 2019 at 11:40:40AM +0000, Ganapathi Bhat wrote: >> Hi Dan, >> >>>> + /* copy the ie's value into ht_capb*/ >>>> + memcpy((u8 *)&sta_ptr->tdls_cap.ht_capb, pos + 2, >>> ^^^^^^^ >>> >>> I don't understand why we changed "pos" to "pos + 2". Presumably there is >>> a reason, but it needs to explained in the commit message. >> >> I think, we were doing wrong in the original code. We are supposed to use 'pos + 2' itself, instead of just 'pos'. This is because, 'pos' is pointing to 'ieee_types_header', followed by the actual data and the destination do not start with (i.e. it do not contain) 'ieee_types_header'(ex: 'sta_ptr->tdls_cap.ht_oper'). >> >> Also, there are few places were the destination starts with 'ieee_types_header'(ex: 'sta_ptr->tdls_cap.extcap'), which need just 'pos'. > > I assumed it was something like this but it needs to be explained in > the commit message. > > regards, > dan carpenter >