On 5/26/20 2:40 PM, Peng Fan wrote:
Subject: Re: [RFC PATCH] imx: skip unused compatible strings in drivers
On Tue, 26 May 2020 13:25:00 +0200 Marek Vasut marex@denx.de wrote:
On 5/26/20 1:12 PM, Soeren Moch wrote:
On 25.05.20 22:24, Anatolij Gustschin wrote:
Converting to DM increases binary size and breaks building some boards (i.e. tbs2910, gcc 9.2). The approach to address this issue via cutting off unused properties/nodes in device tree via custom u-boot.dtsi was not welcome, even if the affected boards do not pass the built-in device tree to the kernel.
But there is CONFIG_OF_REMOVE_PROPS="dmas dma-names
interrupt-parent
interrupts interrupts-extended interrupt-names interrupt-map interrupt-map-mask" in tbs2910_defconfig. So removing properties is already done via this config option. Removing nodes is not implemented (yet? AFAIK). But would be welcome if someone implements this in a similar way, I think.
Why don't we turn this the other way around -- put the { compat string , driver } tuple list into a U-Boot linker list, then filter this linker list against a DT which will be used for the platform (what if there are multiple DTs?), and then scrub all unreferrenced symbols.
This might be a topic again when new bloat causes build breakage again. For now I've succeeded to build the tbs2910 board with default CI tool chain without this patch (by making DM_VIDEO parts optional). Stripping unused compatible entries doesn't save much here (around 800 bytes). So the question is if it is worth the effort to implement such scrubbing.
I vote for this. Whether u-boot or SPL, currently the size is larger and larger.
Can you send a patch prototyping this ?