From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762058AbdLSKsc (ORCPT ); Tue, 19 Dec 2017 05:48:32 -0500 Received: from mga06.intel.com ([134.134.136.31]:32690 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761982AbdLSKs2 (ORCPT ); Tue, 19 Dec 2017 05:48:28 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.45,426,1508828400"; d="scan'208";a="17258281" Message-ID: <1513680504.2569.1.camel@intel.com> Subject: Re: Regression: unable to boot after commit bd9240a18edf ("x86/apic: Add TSC_DEADLINE quirk due to errata") - Surface Pro 4 SKL From: Zhang Rui To: Peter Zijlstra Cc: Thomas Gleixner , LKML , linux-x86 , Len Brown , "Chen, Yu C" Date: Tue, 19 Dec 2017 18:48:24 +0800 In-Reply-To: <20171218202822.juwyxsd7millme7o@hirez.programming.kicks-ass.net> References: <1511834933.2498.14.camel@intel.com> <20171128081440.mi3nrhxgori75cbs@hirez.programming.kicks-ass.net> <1511857335.2498.22.camel@intel.com> <1511866741.2441.5.camel@intel.com> <20171128123607.fmgpq76brf6bdkk4@hirez.programming.kicks-ass.net> <1511966690.2750.9.camel@intel.com> <20171218202822.juwyxsd7millme7o@hirez.programming.kicks-ass.net> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.18.5.2-0ubuntu3 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2017-12-18 at 21:28 +0100, Peter Zijlstra wrote: > Hi, can you see if this makes you Surface boot? > No, it does not boot. > I tested it on my IVB by making has_legacy_pic() return unconditional > true. > > [    0.024000] tsc: Unable to calibrate against PIT > [    0.025000] tsc: using HPET reference calibration > [    0.026000] tsc: Detected 2792.451 MHz processor > > --- > > > diff --git a/arch/x86/include/asm/i8259.h > b/arch/x86/include/asm/i8259.h > index c8376b40e882..e2cfc4b52ee4 100644 > --- a/arch/x86/include/asm/i8259.h > +++ b/arch/x86/include/asm/i8259.h > @@ -69,6 +69,11 @@ struct legacy_pic { >  extern struct legacy_pic *legacy_pic; >  extern struct legacy_pic null_legacy_pic; >   > +static inline bool has_legacy_pic(void) > +{ > + return legacy_pic == &null_legacy_pic; > +} > + shouldn't this be return legacy_pic == &default_legacy_pic; ? thanks, rui >  static inline int nr_legacy_irqs(void) >  { >   return legacy_pic->nr_legacy_irqs; > diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c > index 8ea117f8142e..2afc623b2280 100644 > --- a/arch/x86/kernel/tsc.c > +++ b/arch/x86/kernel/tsc.c > @@ -25,6 +25,7 @@ >  #include >  #include >  #include > +#include >   >  unsigned int __read_mostly cpu_khz; /* TSC clocks / usec, not > used here */ >  EXPORT_SYMBOL(cpu_khz); > @@ -363,6 +364,15 @@ static unsigned long pit_calibrate_tsc(u32 > latch, unsigned long ms, int loopmin) >   unsigned long tscmin, tscmax; >   int pitcnt; >   > + if (!has_legacy_pic()) { > + udelay(10 * USEC_PER_MSEC); > + udelay(10 * USEC_PER_MSEC); > + udelay(10 * USEC_PER_MSEC); > + udelay(10 * USEC_PER_MSEC); > + udelay(10 * USEC_PER_MSEC); > + return ULONG_MAX; > + } > + >   /* Set the Gate high, disable speaker */ >   outb((inb(0x61) & ~0x02) | 0x01, 0x61); >   > @@ -487,6 +497,9 @@ static unsigned long quick_pit_calibrate(void) >   u64 tsc, delta; >   unsigned long d1, d2; >   > + if (!has_legacy_pic()) > + return 0; > + >   /* Set the Gate high, disable speaker */ >   outb((inb(0x61) & ~0x02) | 0x01, 0x61); >