Re: [PATCH] arm64: cpufeature: Enable Qualcomm erratas

Bjorn Andersson
2019-10-29T17:04:04Z

On Tue 29 Oct 04:39 PDT 2019, Will Deacon wrote:

> On Mon, Oct 28, 2019 at 11:04:32PM -0700, Bjorn Andersson wrote:
> > With the introduction of 'cce360b54ce6 ("arm64: capabilities: Filter the
> > entries based on a given mask")' the Qualcomm erratas are no long
> > applied.
> >
> > The result of not applying errata 1003 is that MSM8996 runs into various
> > RCU stalls and fails to boot most of the times.
> >
> > Give both 1003 and 1009 a "type" to ensure they are not filtered out in
> > update_cpu_capabilities().
>
> Oh nasty. Thanks for debugging and fixing this.
>
> > Fixes: cce360b54ce6 ("arm64: capabilities: Filter the entries based on a given mask")
> > Cc: stable@vger.kernel.org
> > Reported-by: Mark Brown <broonie@kernel.org>
> > Suggested-by: Will Deacon <will@kernel.org>
> > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> > ---
> > arch/arm64/kernel/cpu_errata.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
> > index df9465120e2f..cdd8df033536 100644
> > --- a/arch/arm64/kernel/cpu_errata.c
> > +++ b/arch/arm64/kernel/cpu_errata.c
> > @@ -780,6 +780,7 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
> > {
> > .desc = "Qualcomm Technologies Falkor/Kryo erratum 1003",
> > .capability = ARM64_WORKAROUND_QCOM_FALKOR_E1003,
> > + .type = ARM64_CPUCAP_SCOPE_LOCAL_CPU,
> > .matches = cpucap_multi_entry_cap_matches,
>
> This should probably be ARM64_CPUCAP_LOCAL_CPU_ERRATUM instead, but I'll
> want Suzuki's ack before I take the change.
>

Sure thing, will fix!

> > .match_list = qcom_erratum_1003_list,
> > },
> > @@ -788,6 +789,7 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
> > {
> > .desc = "Qualcomm erratum 1009, ARM erratum 1286807",
> > .capability = ARM64_WORKAROUND_REPEAT_TLBI,
> > + .type = ARM64_CPUCAP_SCOPE_LOCAL_CPU,
> > ERRATA_MIDR_RANGE_LIST(arm64_repeat_tlbi_cpus),
>
> ERRATA_MIDR_RANGE_LIST sets the type already, so I think this is redundant.
>

You're right, I got lost in the macros. Apologies for that.

Will respin the patch.

Thanks,
Bjorn