James, On 2017/9/1 1:44, James Morse wrote: > Hi Dongjiu Geng, > > On 28/08/17 11:38, Dongjiu Geng wrote: >> From: Xie XiuQi <xiexiuqi@xxxxxxxxxx> >> >> ARM's v8.2 Extentions add support for Reliability, Availability and >> Serviceability (RAS). On CPUs with these extensions system software >> can use additional barriers to isolate errors and determine if faults >> are pending. >> >> Add cpufeature detection and a barrier in the context-switch code. >> There is no need to use alternatives for this as CPUs that don't >> support this feature will treat the instruction as a nop. >> >> Platform level RAS support may require additional firmware support. >> >> Signed-off-by: Xie XiuQi <xiexiuqi@xxxxxxxxxx> >> [Rebased, added esb and config option, reworded commit message] >> Signed-off-by: James Morse <james.morse@xxxxxxx> > > Nit: when re-posting patches from the list you need to add your signed-off-by. > See Documentation/process/submitting-patches.rst 'Developer's Certificate of > Origin 1.1' Ok, thanks for the your pointing out. > > This goes for your patch 2 as well. > > >> diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c >> index c845c8c04d95..7a17b4a1bd9e 100644 >> --- a/arch/arm64/kernel/process.c >> +++ b/arch/arm64/kernel/process.c >> @@ -370,6 +370,9 @@ __notrace_funcgraph struct task_struct *__switch_to(struct task_struct *prev, >> */ >> dsb(ish); >> >> + /* Deliver any pending SError from prev */ >> + esb(); >> + > > This patch was sitting on top of the SError rework. As the cover-letter > describes that was all there to make sure SError is unmasked when we execute > this esb(). Without it any pending SError will be deferred, its ESR is written > to DISR_EL1, which this patch doesn't check. > > On its own, this patch is actively harmful to systems that don't have > firmware-first handling. > > We probably need to produce a combined series... OK, thanks for your reminder and detailed explanation. > > > Thanks, > > James > > > . > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html