| Message ID | 20210117180301.1956-3-alistair@alistair23.me |
|---|---|
| State | New |
| Headers | show |
| Series | [v2,1/3] imx7d-remarkable2.dts: Initial device tree for reMarkable2 | expand |
On Sun, Jan 17, 2021 at 10:03:01AM -0800, Alistair Francis wrote: > The reMarkable2 requires VMSPLIT_2G, so lets set this in the > imx_v6_v7_defconfig. Hmm, why is VMSPLIT_2G required by reMarkable2? Shawn > > Signed-off-by: Alistair Francis <alistair@alistair23.me> > --- > arch/arm/configs/imx_v6_v7_defconfig | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/arm/configs/imx_v6_v7_defconfig b/arch/arm/configs/imx_v6_v7_defconfig > index 55674cb1ffce..fa9229616106 100644 > --- a/arch/arm/configs/imx_v6_v7_defconfig > +++ b/arch/arm/configs/imx_v6_v7_defconfig > @@ -29,6 +29,7 @@ CONFIG_SOC_IMX7D=y > CONFIG_SOC_IMX7ULP=y > CONFIG_SOC_VF610=y > CONFIG_SMP=y > +CONFIG_VMSPLIT_2G=y > CONFIG_ARM_PSCI=y > CONFIG_HIGHMEM=y > CONFIG_FORCE_MAX_ZONEORDER=14 > -- > 2.29.2 >
On Thu, Jan 28, 2021 at 11:13 PM Shawn Guo <shawnguo@kernel.org> wrote: > > On Sun, Jan 17, 2021 at 10:03:01AM -0800, Alistair Francis wrote: > > The reMarkable2 requires VMSPLIT_2G, so lets set this in the > > imx_v6_v7_defconfig. > > Hmm, why is VMSPLIT_2G required by reMarkable2? I'm not too sure. It's difficult to debug problems as I only have a UART but without this I don't see any kernel prints so it seems like the kernel doesn't get very far. I haven't had any luck with earlycon on the device so I don't know how I can get more information. Alistair > > Shawn > > > > > Signed-off-by: Alistair Francis <alistair@alistair23.me> > > --- > > arch/arm/configs/imx_v6_v7_defconfig | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/arch/arm/configs/imx_v6_v7_defconfig b/arch/arm/configs/imx_v6_v7_defconfig > > index 55674cb1ffce..fa9229616106 100644 > > --- a/arch/arm/configs/imx_v6_v7_defconfig > > +++ b/arch/arm/configs/imx_v6_v7_defconfig > > @@ -29,6 +29,7 @@ CONFIG_SOC_IMX7D=y > > CONFIG_SOC_IMX7ULP=y > > CONFIG_SOC_VF610=y > > CONFIG_SMP=y > > +CONFIG_VMSPLIT_2G=y > > CONFIG_ARM_PSCI=y > > CONFIG_HIGHMEM=y > > CONFIG_FORCE_MAX_ZONEORDER=14 > > -- > > 2.29.2 > >
On Wed, Feb 3, 2021 at 3:37 AM Alistair Francis <alistair23@gmail.com> wrote: > > On Thu, Jan 28, 2021 at 11:13 PM Shawn Guo <shawnguo@kernel.org> wrote: > > > > On Sun, Jan 17, 2021 at 10:03:01AM -0800, Alistair Francis wrote: > > > The reMarkable2 requires VMSPLIT_2G, so lets set this in the > > > imx_v6_v7_defconfig. > > > > Hmm, why is VMSPLIT_2G required by reMarkable2? > > I'm not too sure. It's difficult to debug problems as I only have a > UART but without this I don't see any kernel prints so it seems like > the kernel doesn't get very far. I haven't had any luck with earlycon > on the device so I don't know how I can get more information. In the dts file, I can see that the machine has 1GB of RAM at contiguous addresses. My first guess would be a problem with highmem, as this configuration means that with VMSPLIT_3G there are 768MB of lowmem and 256MB of highmem. Can you try these two things to narrow the problem down further? a) disable CONFIG_HIGHMEM when using VMSPLIT_3G b) use VMSPLIT_3G_OPT If both of them solve the problem, then highmem is likely the root cause. One possible issue might be that the boot loader loads the initramfs or the dtb into a location outside of the first 768 MB of lowmem where it is unreachable in the VMSPLIT_3G configuration. Arnd
On Tue, Feb 2, 2021 at 11:50 PM Arnd Bergmann <arnd@kernel.org> wrote: > > On Wed, Feb 3, 2021 at 3:37 AM Alistair Francis <alistair23@gmail.com> wrote: > > > > On Thu, Jan 28, 2021 at 11:13 PM Shawn Guo <shawnguo@kernel.org> wrote: > > > > > > On Sun, Jan 17, 2021 at 10:03:01AM -0800, Alistair Francis wrote: > > > > The reMarkable2 requires VMSPLIT_2G, so lets set this in the > > > > imx_v6_v7_defconfig. > > > > > > Hmm, why is VMSPLIT_2G required by reMarkable2? > > > > I'm not too sure. It's difficult to debug problems as I only have a > > UART but without this I don't see any kernel prints so it seems like > > the kernel doesn't get very far. I haven't had any luck with earlycon > > on the device so I don't know how I can get more information. > > In the dts file, I can see that the machine has 1GB of RAM at > contiguous addresses. My first guess would be a problem with > highmem, as this configuration means that with VMSPLIT_3G > there are 768MB of lowmem and 256MB of highmem. > > Can you try these two things to narrow the problem down > further? > > a) disable CONFIG_HIGHMEM when using VMSPLIT_3G > b) use VMSPLIT_3G_OPT Thanks Arnd, I was working on testing the config changes you mentioned, but it seems like all of them work now. VMSPLIT_2G: Boots to userspace VMSPLIT_3G && HIGHMEM: Boots to userspace VMSPLIT_3G && !HIGHMEM: Boots to userspace VMSPLIT_3G_OPT && HIGHMEM:Boots to userspace > > If both of them solve the problem, then highmem is likely > the root cause. One possible issue might be that the boot > loader loads the initramfs or the dtb into a location outside > of the first 768 MB of lowmem where it is unreachable > in the VMSPLIT_3G configuration. It boots with u-boot, which I am building so I can change these addresses. I'm guessing that I have changed the addresses at some point and now it works. I'm going to drop this patch. Alistair > > Arnd
diff --git a/arch/arm/configs/imx_v6_v7_defconfig b/arch/arm/configs/imx_v6_v7_defconfig index 55674cb1ffce..fa9229616106 100644 --- a/arch/arm/configs/imx_v6_v7_defconfig +++ b/arch/arm/configs/imx_v6_v7_defconfig @@ -29,6 +29,7 @@ CONFIG_SOC_IMX7D=y CONFIG_SOC_IMX7ULP=y CONFIG_SOC_VF610=y CONFIG_SMP=y +CONFIG_VMSPLIT_2G=y CONFIG_ARM_PSCI=y CONFIG_HIGHMEM=y CONFIG_FORCE_MAX_ZONEORDER=14
The reMarkable2 requires VMSPLIT_2G, so lets set this in the imx_v6_v7_defconfig. Signed-off-by: Alistair Francis <alistair@alistair23.me> --- arch/arm/configs/imx_v6_v7_defconfig | 1 + 1 file changed, 1 insertion(+)