On Thu, 7 May 2020 14:38:52 +0800 "Ramuthevar, Vadivel MuruganX" <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx> wrote: > Hi Boris, > > Thank you very much for the review comments and your time... > > On 7/5/2020 2:27 pm, Boris Brezillon wrote: > > On Thu, 7 May 2020 14:13:42 +0800 > > "Ramuthevar, Vadivel MuruganX" > > <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx> wrote: > > > >> Hi Boris, > >> > >> Thank you very much for the review comments and your time... > >> > >> On 7/5/2020 1:28 pm, Boris Brezillon wrote: > >>> On Thu, 7 May 2020 08:15:37 +0800 > >>> "Ramuthevar,Vadivel MuruganX" > >>> <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx> wrote: > >>> > >>>> + reg = readl(ebu_host->ebu + EBU_ADDR_SEL(ebu_host->cs_num)); > >>>> + writel(reg | EBU_ADDR_MASK(5) | EBU_ADDR_SEL_REGEN, > >>>> + ebu_host->ebu + EBU_ADDR_SEL(ebu_host->cs_num)); > >>> > >>> Seriously, did you really think I would not notice what you're doing > >>> here? > >> Yes , I know that you have very good understanding about this. > >> You're reading the previous value which either contains a default > >>> mapping or has the mapping set by the bootloader, and write it back to > >>> the register along with a new mask and the REGEN bit set (which > >>> BTW is wrong since you don't mask out other fields before updating > >>> them). > >> There is no other field get overwritten > >> This confirms that this Core -> FPI address translation exists > >>> and has to be set properly, so please stop lying about that. > >> > >> Sorry, there is no SW translation, as I have mentioned that it's > >> optional only, for safer side , reading and writing the default values. > > > > Then write EBU_ADDR_SEL_REGEN and we'll if see that works. I suspect it > > won't. > > You mean, without reading just writing EBU_ADDR_SEL_REGEN bit alone in > EBU_ADDR_SELx , as you said it won't work because it overwrites 0x174 > with 0x0 values so BASE is lost. Which confirms that this mapping has to be defined. > either we can leave it or read & write with ORed | EBU_ADDR_SEL_REGEN None of this is acceptable IMO. You have to build the value based on the address translation described in the DT. Why are you so reluctant to this approach? > > Please correct me if anything is wrong, Thanks! > > > >> The memory region to enabled that's my concern so written the same > >> register values. > > > > I don't buy that, sorry. > > > >> > >> This will not be impact other fields, so please see below for reference > >> > >> The EBU Address Select Registers EBU_ADDR_SEL_0 to EBU_ADDSEL3 establish > >> and control memory regions for external accesses. > >> > >> Reset Value: 17400001H > > > > See, as suspected the reset value is exactly what you expect. > > Yes , that's the reason said being optional. Then it's not optional. It just works because you use the default value.
