Re: [PATCH v3] MIPS: add support for buggy MT7621S core detection

[Thomas Bogendoerfer]

On Wed, Apr 07, 2021 at 01:07:38PM -0700, Ilya Lipnitskiy wrote:
> Most MT7621 SoCs have 2 cores, which is detected and supported properly
> by CPS.
> 
> Unfortunately, MT7621 SoC has a less common S variant with only one core.
> On MT7621S, GCR_CONFIG still reports 2 cores, which leads to hangs when
> starting SMP. CPULAUNCH registers can be used in that case to detect the
> absence of the second core and override the GCR_CONFIG PCORES field.
> 
> Rework a long-standing OpenWrt patch to override the value of
> mips_cps_numcores on single-core MT7621 systems.
> 
> Tested on a dual-core MT7621 device (Ubiquiti ER-X) and a single-core
> MT7621 device (Netgear R6220).
> 
> Original 4.14 OpenWrt patch:
> Link: https://git.openwrt.org/?p=openwrt/openwrt.git;a=commitdiff;h=4cdbc90a376dd0555201c1434a2081e055e9ceb7
> Current 5.10 OpenWrt patch:
> Link: https://git.openwrt.org/?p=openwrt/openwrt.git;a=blob;f=target/linux/ramips/patches-5.10/320-mt7621-core-detect-hack.patch;h=c63f0f4c1ec742e24d8480e80553863744b58f6a;hb=10267e17299806f9885d086147878f6c492cb904
> 
> Suggested-by: Felix Fietkau <nbd@xxxxxxxx>
> Signed-off-by: Ilya Lipnitskiy <ilya.lipnitskiy@xxxxxxxxx>
> ---
>  arch/mips/include/asm/mips-cps.h | 23 ++++++++++++++++++++++-
>  1 file changed, 22 insertions(+), 1 deletion(-)

applied to mips-next.

Thomas.

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