On Mon, Jan 16, 2017 at 2:39 AM, Neil Armstrong <narmstrong@xxxxxxxxxxxx> wrote: > On 01/15/2017 03:43 PM, Andreas Färber wrote: >> Am 13.01.2017 um 21:03 schrieb Kevin Hilman: >>> Neil Armstrong <narmstrong@xxxxxxxxxxxx> writes: >>> >>>> The Amlogic Meson GXBB/GXL/GXM secure monitor uses part of the memory space, >>>> this patch adds this reserved zone and redefines the usable memory range. >>>> >>>> The memory node is also moved from the dtsi files into the proper dts files >>>> to handle variants memory sizes. >>>> >>>> This patch also fixes the memory sizes for the following platforms : >>>> - gxl-s905x-p212 : 1GiB instead of 2GiB, a proper 2GiB dts should be pushed >>>> - gxm-s912-q201 : 1GiB instead of 2GiB, a proper 2GiB dts should be pushed >>>> - gxl-s905d-p231 : 1GiB instead of 2GiB, a proper 2GiB dts should be pushed >>>> - gxl-nexbox-a95x : 1GiB instead of 2GiB, a proper 2GiB dts should be pushed >>>> >>>> Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx> >>> >>> Queued for v4.10-rc. >> >> What is the motivation for this change? I have a local U-Boot patch to >> detect the amount of memory available as done downstream, but U-Boot >> only updates the reg property that you seem to be abandoning here... >> >> So for devices that come in multiple RAM configurations - like R-Box Pro >> - this would require separate .dts files now! This looks very wrong to >> me, especially since I am not aware of other platforms doing the same. >> Instead, there's memory reservations for top and bottom done in U-Boot >> for reg, plus reserved-memory nodes for anything in the middle. >> >> Another thing to consider is that uEFI boot (bootefi) handles memory >> reservation differently yet again, on the bootloader level. I have had >> that working fine on Odroid-C2 and Vega S95. >> >> So if there's no bug this is fixing (none mentioned in commit message) I >> strongly object to this patch. >> >> Regards, >> Andreas >> > > Hi Andreas, > > Like I replied of my RFT patch : > I really disagree about relying on any work or properties added by any bootloader here, Amlogic SoCs has > a lot of u-boot versions in the field, and the Odroid-C2 is part of this. > > Even if Odroid-c2 is in mainline U-Boot or not, the mainline Linux kernel should work using > any U-boot version even with the one provided by Amlogic on their openlinux distribution channel. > > Handling multiple RAM configuration is another story, and the Arm-Soc and DT maintainers should give us > their advices. Is there a way to detect what firmware is running and marking off memory from early kernel init instead? That'll take care of the concerns about memory size variance as well. > Actually there is a severe bug fixed here that cause a huge crash if such memory is not reserved while > running stock u-boot version on various shipped products and Amlogic's own development boards. > > The bug is easily triggered by running : > # stress --vm 4 --vm-bytes 128M --timeout 10s & > [ 46.937975] Bad mode in Error handler detected on CPU1, code 0xbf000000 -- SError > ... > [ 47.058536] Internal error: Attempting to execute userspace memory: 8600000f [#3] PREEMPT SMP > ... > > Note this is a fix targeted for 4.10 to make the system stable and various users reported some severe > crash now the system has more drivers and read-world use-cases are running on Amlogic SoCs. > > Please feel free to push whatever changes that makes this memory reservation more coherent for 4.11, > and respect the behavior of already shipped u-boot version and mainline U-Boot, UEFI, whatever... Technically we're not in regression territory here, since the platform is obviously still in bringup and these aren't bugs that have been introduced in this release. So I think we can take a little while to sort out if there's a solution that, even if not ideal, at least is on the path towards the proper fix and not away from it -- which this seems to be. -Olof -- 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
