From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Wei, Gang" Subject: RE: [PATCH] x86: suppress HPET broadcast initialization in the presence of ARAT Date: Sat, 12 Feb 2011 15:15:34 +0800 Message-ID: References: <4D53FD3202000078000313F5@vpn.id2.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <4D53FD3202000078000313F5@vpn.id2.novell.com> Content-Language: en-US List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Jan Beulich , "xen-devel@lists.xensource.com" Cc: "Wei, Gang" List-Id: xen-devel@lists.xenproject.org Jan Beulich wrote on=A02011-02-10: > This follows Linux commit 39fe05e58c5e448601ce46e6b03900d5bf31c4b0, > noticing that all this setup is pointless when ARAT support is there,=20 > and knowing that on SLED11's native kernel it has actually caused S3 resu= me issues. >=20 > A question would be whether HPET legacy interrupts should be forced=20 > off in this case (rather than leaving whatever came from firmware). >=20 > Signed-off-by: Jan Beulich >=20 > --- a/xen/arch/x86/hpet.c > +++ b/xen/arch/x86/hpet.c > @@ -557,6 +557,9 @@ void hpet_broadcast_init(void) > u32 hpet_id, cfg; > int i; > + if ( boot_cpu_has(X86_FEATURE_ARAT) ) > + return; > + > if ( irq_channel =3D=3D NULL ) > { > irq_channel =3D xmalloc_array(int, nr_irqs); > Although this patch was already checked in, I still have to say it is not n= ecessary for Xen. Because hpet_broadcast_init() fn is only called if (xen_c= puidle && !boot_cpu_has(X86_FEATURE_ARAT)) in disable_pit_irq(). Of course = I agree to keep it as a never used double check. Jimmy