cpufreq: armada-37xx: forbid cpufreq for 1.2 GHz variant
[ Upstream commit 484f2b7c61b9ae58cc00c5127bcbcd9177af8dfe ]
The 1.2 GHz variant of the Armada 3720 SOC is unstable with DVFS: when
the SOC boots, the WTMI firmware sets clocks and AVS values that work
correctly with 1.2 GHz CPU frequency, but random crashes occur once
cpufreq driver starts scaling.
We do not know currently what is the reason:
- it may be that the voltage value for L0 for 1.2 GHz variant provided
by the vendor in the OTP is simply incorrect when scaling is used,
- it may be that some delay is needed somewhere,
- it may be something else.
The most sane solution now seems to be to simply forbid the cpufreq
driver on 1.2 GHz variant.
Signed-off-by: Marek Behún <kabel@kernel.org>
Fixes: 92ce45fb875d ("cpufreq: Add DVFS support for Armada 37xx")
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
1 file changed