On Mon, May 28, 2018 at 10:54:57AM +0200, Geert Uytterhoeven wrote:
> Hi Simon,
>
> On Mon, May 28, 2018 at 10:41 AM, Simon Horman <horms@xxxxxxxxxxxx> wrote:
> > On Thu, May 24, 2018 at 04:52:59PM +0200, Marek Vasut wrote:
> >> On 05/23/2018 08:25 AM, Geert Uytterhoeven wrote:
> >> > On Wed, May 23, 2018 at 12:01 AM, Marek Vasut <marek.vasut@xxxxxxxxx> wrote:
> >> >> On 05/22/2018 04:43 PM, Geert Uytterhoeven wrote:
> >> >>> On Tue, May 22, 2018 at 2:02 PM, Marek Vasut <marek.vasut@xxxxxxxxx> wrote:
> >> >>>> Drop the MTD partitioning from DT, since it does not describe HW
> >> >>>> and to give way to a more flexible kernel command line partition
> >> >>>> passing.
> >> >>>>
> >> >>>> To retain the original partitioning, assure you have enabled
> >> >>>> CONFIG_MTD_CMDLINE_PARTS in your kernel config and add the
> >> >>>> following to your kernel command line:
> >> >>>>
> >> >>>> mtdparts=spi0.0:256k@0(loader),4096k(user),-(flash)
> >> >>>
> >> >>> I think the "@0" can be dropped, as it's optional?
> >> >>> 4m?
> >> >>
> >> >> My take on this is that the loader is actually at offset 0x0 of the MTD
> >> >> device and we explicitly state that in the mtdparts to anchor the first
> >> >> partition within the MTD device and all the other partitions are at
> >> >> offset +(sum of the sizes of all partitions listed before the current
> >> >> one) relative to that first partition.
> >> >
> >> > Where is this explicitly states for the first partition?
> >> >
> >> >> Removing the @0 feels fragile at best and it seems to depend on the
> >> >> current behavior of the code.
> >> >
> >> > Better, it also depends on the documented behavior:
> >> >
> >> > Documentation/admin-guide/kernel-parameters.txt refers to
> >> > drivers/mtd/cmdlinepart.c, which states:
> >> >
> >> > * <offset> := standard linux memsize
> >> > * if omitted the part will immediately follow the previous part
> >> > * or 0 if the first part
> >> >
> >> > None of the examples listed there or under the MTD_CMDLINE_PARTS Kconfig
> >> > help text, or in a defconfig bundled with the kernel, use @0 for the first
> >> > partition.
> >>
> >> I think this is exceptionally fragile and dangerous to depend on this,
> >> but so be it.
> >
> > Could you respin with this change?
> >
> > I would also like to ask for another change, in light of recent
> > feedback from Olof Johansson ("Re: [GIT PULL] Renesas ARM64 Based SoC DT
> > Updates for v4.18").
> >
> > Please consolidate the dts patches into a single patch?
>
> I think it's better to keep them split, as each commit description mentions
> what needs to be passed on the kernel command line for the corresponding
> board.
>
> Combining it in a single patch makes it much harder to extract this information.
> Unless you're fine with a list:
>
> koelsch: ...
> wheat: mtdparts=spi0.0:256k@0(loader),4096k(user),-(flash)
Lets try a list.
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
