[PATCH 6/9] ARM: dts: wheat: Drop MTD partitioning from DT
From: Marek Vasut <hidden>
Date: 2018-05-30 10:13:31
Also in:
linux-devicetree, linux-renesas-soc
On 05/28/2018 11:36 AM, Simon Horman wrote:
On Mon, May 28, 2018 at 10:54:57AM +0200, Geert Uytterhoeven wrote:quoted
Hi Simon, On Mon, May 28, 2018 at 10:41 AM, Simon Horman [off-list ref] wrote:quoted
On Thu, May 24, 2018 at 04:52:59PM +0200, Marek Vasut wrote:quoted
On 05/23/2018 08:25 AM, Geert Uytterhoeven wrote:quoted
On Wed, May 23, 2018 at 12:01 AM, Marek Vasut [off-list ref] wrote:quoted
On 05/22/2018 04:43 PM, Geert Uytterhoeven wrote:quoted
On Tue, May 22, 2018 at 2:02 PM, Marek Vasut [off-list ref] wrote:quoted
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 at 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?quoted
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 at 0(loader),4096k(user),-(flash)Lets try a list.
Reposted with a list, twice :/ -- Best regards, Marek Vasut