Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752445Ab3HUHej (ORCPT ); Wed, 21 Aug 2013 03:34:39 -0400 Received: from terminus.zytor.com ([198.137.202.10]:35732 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752398Ab3HUHeh (ORCPT ); Wed, 21 Aug 2013 03:34:37 -0400 User-Agent: K-9 Mail for Android In-Reply-To: <20130821072940.GB27495@gmail.com> References: <1377049949.18357.3.camel@fli24-HP-Compaq-8100-Elite-CMT-PC> <20130821072940.GB27495@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: Re: [PATCH] reboot: perform warm/cold reset correctly for CF9 type From: "H. Peter Anvin" Date: Wed, 21 Aug 2013 09:33:23 +0200 To: Ingo Molnar , Li Fei CC: mingo@redhat.com, tglx@linutronix.de, chuansheng.liu@intel.com, x86@kernel.org, akpm@linux-foundation.org, holt@sgi.com, rmk+kernel@arm.linux.org.uk, linux-kernel@vger.kernel.org Message-ID: <69b80c44-3245-4393-b6e9-4d8a7f3d3c66@email.android.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1948 Lines: 59 Careful. This is a very different definition of warm vs cold boot used elsewhere. Ingo Molnar wrote: > >* Li Fei wrote: > >> In current implementation for reboot type CF9 and CF9_COND, >> warm and cold reset are not differentiated, and both are >> performed by writing 0x06 to port 0xCF9 as warm reset. It's not >> correct. >> >> This commit will differentiate warm and cold reset, and perform >> them correctly as below: >> For warm reset, write 0x06 to port 0xCF9; >> For cold reset, write 0x0E to port 0xCF9. >> >> From: Liu Chuansheng >> Signed-off-by: Li Fei >> --- >> arch/x86/kernel/reboot.c | 9 +++++++-- >> 1 files changed, 7 insertions(+), 2 deletions(-) >> >> diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c >> index 563ed91..6e06299 100644 >> --- a/arch/x86/kernel/reboot.c >> +++ b/arch/x86/kernel/reboot.c >> @@ -511,10 +511,15 @@ static void >native_machine_emergency_restart(void) >> >> case BOOT_CF9_COND: >> if (port_cf9_safe) { >> - u8 cf9 = inb(0xcf9) & ~6; >> + u8 cf9 = inb(0xcf9) & >> + ~(reboot_mode == REBOOT_WARM ? >> + 0x06 : 0x0E); >> outb(cf9|2, 0xcf9); /* Request hard reset */ >> udelay(50); >> - outb(cf9|6, 0xcf9); /* Actually do the reset */ >> + /* Actually do the reset */ >> + outb(cf9|(reboot_mode == REBOOT_WARM ? >> + 0x06 : 0x0E), >> + 0xcf9); >> udelay(50); > >Looks good, but please introduce a reboot_val intermediate >variable instead of duplicating that ugly line-broken >construct twice. > >Thanks, > > Ingo -- Sent from my mobile phone. Please excuse brevity and lack of formatting. -- 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/