Re: [PATCH v5 2/2] mtd: rawnand: Add NAND controller support on Intel LGM SoC

Boris Brezillon
2020-05-07T06:27:46Z

On Thu, 7 May 2020 14:13:42 +0800
"Ramuthevar, Vadivel MuruganX"
<vadivel.muruganx.ramuthevar@linux.intel.com> 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@linux.intel.com> 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.

> 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.