Hi Bean, On Mon, 2020-01-13 at 09:28 +0000, Bean Huo (beanhuo) wrote: > Hi, Stanley > > > > > Currently checking if an error history element is empty or not is by its "value". In > > most cases, value is error code. > > > > However this checking is not correct because some errors or events do not > > specify any values in error history so values remain as 0, and this will lead to > > incorrect empty checking. > > > Do you think this is a bug of UFS host controller? According to the UFS host Spec, > If there had error detected in each layer, at least bit31 in its error code register > Should be set to 1. > > Why there was an error happening, but host didn't set this bit31? > Thanks so much for review. Yes, the case bit[31] set is true for UIC errors. However the users of UFS error history, i.e., users of ufshcd_update_reg_hlist(), are not only UIC errors. Some other essential events will update history too, for example, device reset events and abort events. Take "device reset events" as example: parameter "val" may be 0 while invoking ufshcd_update_reg_hlist(). If this happens, the device reset event will not be printed out because its err_hist->reg[p] is 0 according to the original logic in ufshcd_print_err_hist(). Feel free to correct above description if it is wrong. Thanks, Stanley
