Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933474AbXLNNPo (ORCPT ); Fri, 14 Dec 2007 08:15:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759459AbXLNNPd (ORCPT ); Fri, 14 Dec 2007 08:15:33 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:42645 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1765851AbXLNNPc (ORCPT ); Fri, 14 Dec 2007 08:15:32 -0500 Date: Fri, 14 Dec 2007 14:15:03 +0100 From: Ingo Molnar To: "David P. Reed" Cc: Thomas Gleixner , linux-kernel@vger.kernel.org, Ingo Molnar , "H. Peter Anvin" , Rene Herman , Pavel Machek Subject: Re: [PATCH] x86_64: fix problems due to use of "outb" to port 80 on some AMD64x2 laptops, etc. Message-ID: <20071214131502.GA14359@elte.hu> References: <466F0941.9060201@reed.com> <1181682498.8176.224.camel@chaos> <469578CD.3080609@reed.com> <1184216528.12353.203.camel@chaos> <1184218962.12353.209.camel@chaos> <46964352.7040301@reed.com> <1184253339.12353.223.camel@chaos> <469697C6.50903@reed.com> <1184274754.12353.254.camel@chaos> <4761F193.7090400@reed.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4761F193.7090400@reed.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5244 Lines: 152 * David P. Reed wrote: > Replace use of outb to "unused" diagnostic port 0x80 for time delay > with udelay based time delay on x86_64 architecture machines. Fix for > bugs 9511 and 6307 in bugzilla, plus bugs reported in > bugzilla.redhat.com. > > Derived from suggestion (that didn't compile) by Pavel Machek, and > tested, also based on measurements of typical timings of out's > collated by Rene Herman from many in the community. > > This patch fixes a number of bugs known to cause problems on HP > Pavilion dv9000z and dv6000z laptops - in the form of solid freezes > when hwclock is used to show or set the time. Also, it potentially > improves bus utilization on SMP machines, by using a waiting process > that doesn't tie up the ISA/LPC bus for 1 or 2 microseconds. > > i386 family fixes (completely parallel) were not included, considering > that such machines might involve more risk of problems on legacy > machines. wow, cool fix! (I remember that there were other systems as well that are affected by port 0x80 muckery - i thought we had removed port 0x80 accesses long ago.) how about the simpler fix below, as a first-level approach? We can then remove the _p in/out sequences after this. this is also something for v2.6.24 merging. Ingo -----------------------------> Subject: x86: fix in/out_p delays From: Ingo Molnar Debugged by David P. Reed . Do not use port 0x80, it can cause crashes, see: http://bugzilla.kernel.org/show_bug.cgi?id=6307 http://bugzilla.kernel.org/show_bug.cgi?id=9511 instead of just removing _p postfixes en masse, lets just first remove the 0x80 port usage, then remove any unnecessary _p io ops gradually. It's more debuggable this way. Signed-off-by: Ingo Molnar --- arch/x86/boot/compressed/misc_32.c | 8 ++++---- arch/x86/boot/compressed/misc_64.c | 8 ++++---- arch/x86/kernel/quirks.c | 9 +++++++++ include/asm-x86/io_32.h | 5 +---- include/asm-x86/io_64.h | 5 +---- 5 files changed, 19 insertions(+), 16 deletions(-) Index: linux-x86.q/arch/x86/boot/compressed/misc_32.c =================================================================== --- linux-x86.q.orig/arch/x86/boot/compressed/misc_32.c +++ linux-x86.q/arch/x86/boot/compressed/misc_32.c @@ -276,10 +276,10 @@ static void putstr(const char *s) RM_SCREEN_INFO.orig_y = y; pos = (x + cols * y) * 2; /* Update cursor position */ - outb_p(14, vidport); - outb_p(0xff & (pos >> 9), vidport+1); - outb_p(15, vidport); - outb_p(0xff & (pos >> 1), vidport+1); + outb(14, vidport); + outb(0xff & (pos >> 9), vidport+1); + outb(15, vidport); + outb(0xff & (pos >> 1), vidport+1); } static void* memset(void* s, int c, unsigned n) Index: linux-x86.q/arch/x86/boot/compressed/misc_64.c =================================================================== --- linux-x86.q.orig/arch/x86/boot/compressed/misc_64.c +++ linux-x86.q/arch/x86/boot/compressed/misc_64.c @@ -275,10 +275,10 @@ static void putstr(const char *s) RM_SCREEN_INFO.orig_y = y; pos = (x + cols * y) * 2; /* Update cursor position */ - outb_p(14, vidport); - outb_p(0xff & (pos >> 9), vidport+1); - outb_p(15, vidport); - outb_p(0xff & (pos >> 1), vidport+1); + outb(14, vidport); + outb(0xff & (pos >> 9), vidport+1); + outb(15, vidport); + outb(0xff & (pos >> 1), vidport+1); } static void* memset(void* s, int c, unsigned n) Index: linux-x86.q/arch/x86/kernel/quirks.c =================================================================== --- linux-x86.q.orig/arch/x86/kernel/quirks.c +++ linux-x86.q/arch/x86/kernel/quirks.c @@ -6,6 +6,15 @@ #include +/* + * Some legacy devices need delays for IN/OUT sequences. Most are + * probably not needed but it's the safest to just do this short delay: + */ +void native_io_delay(void) +{ + udelay(1); +} + #if defined(CONFIG_X86_IO_APIC) && defined(CONFIG_SMP) && defined(CONFIG_PCI) static void __devinit quirk_intel_irqbalance(struct pci_dev *dev) Index: linux-x86.q/include/asm-x86/io_32.h =================================================================== --- linux-x86.q.orig/include/asm-x86/io_32.h +++ linux-x86.q/include/asm-x86/io_32.h @@ -250,10 +250,7 @@ static inline void flush_write_buffers(v #endif /* __KERNEL__ */ -static inline void native_io_delay(void) -{ - asm volatile("outb %%al,$0x80" : : : "memory"); -} +extern void native_io_delay(void); #if defined(CONFIG_PARAVIRT) #include Index: linux-x86.q/include/asm-x86/io_64.h =================================================================== --- linux-x86.q.orig/include/asm-x86/io_64.h +++ linux-x86.q/include/asm-x86/io_64.h @@ -35,10 +35,7 @@ * - Arnaldo Carvalho de Melo */ -static inline void native_io_delay(void) -{ - asm volatile("outb %%al,$0x80" : : : "memory"); -} +extern void native_io_delay(void); #if defined(CONFIG_PARAVIRT) #include -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/