From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: 2.6.19: ACPI reports AC not present after resume from STD Date: Sun, 25 Feb 2007 11:51:11 +0100 Message-ID: <200702251151.12107.rjw@sisk.pl> References: <8E389A5F2FEABA4CB1DEC35A25CB39CE82FE9F@mssmsx411> <200702251117.30462.rjw@sisk.pl> <200702251337.08914.arvidjaar@mail.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <200702251337.08914.arvidjaar@mail.ru> Content-Disposition: inline Sender: linux-acpi-owner@vger.kernel.org To: Andrey Borzenkov Cc: "Lebedev, Vladimir P" , "Karasyov, Konstantin A" , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pm@lists.osdl.org List-Id: linux-pm@vger.kernel.org On Sunday, 25 February 2007 11:37, Andrey Borzenkov wrote: > On =D0=92=D0=BE=D1=81=D0=BA=D1=80=D0=B5=D1=81=D0=B5=D0=BD=D1=8C=D0=B5= 25 =D1=84=D0=B5=D0=B2=D1=80=D0=B0=D0=BB=D1=8F 2007, Rafael J. Wysocki = wrote: > > On Sunday, 25 February 2007 00:26, Andrey Borzenkov wrote: > > > On =D0=A1=D1=83=D0=B1=D0=B1=D0=BE=D1=82=D0=B0 24 =D1=84=D0=B5=D0=B2= =D1=80=D0=B0=D0=BB=D1=8F 2007, Rafael J. Wysocki wrote: > > > > Hi, > > > > > > > > On Saturday, 24 February 2007 10:55, Andrey Borzenkov wrote: > > > > > On =D0=92=D1=82=D0=BE=D1=80=D0=BD=D0=B8=D0=BA 13 =D1=84=D0=B5= =D0=B2=D1=80=D0=B0=D0=BB=D1=8F 2007, Andrey Borzenkov wrote: > > > > > > On =D0=A7=D0=B5=D1=82=D0=B2=D0=B5=D1=80=D0=B3 07 =D0=B4=D0=B5= =D0=BA=D0=B0=D0=B1=D1=80=D1=8F 2006, Lebedev, Vladimir P wrote: > > > > > > > Please register new bug, attach acpidump and dmesg. > > > > > > > > > > > > http://bugzilla.kernel.org/show_bug.cgi?id=3D7995 > > > > > > > > > > > > regards > > > > > > > > > > Well, this starts looking like ACPI is not at fault. > > > > > > > > > > When reporting AC state ACPI just reads contents of system me= mory (I > > > > > presume it gets updated by BIOS/ACPI when AC state changes). = It looks > > > > > like this memory area is restored during resume from STD. I u= pdated > > > > > mentioned bug report with more detailed description. Now if s= omeone > > > > > could suggest a way to catch if specific physical address get= s > > > > > saved/restored this would finally explain it. > > > > > > > > First, if you want the reserved memory areas to be left alone b= y > > > > swsusp, you need to mark them as 'nosave'. On x86_64 this is d= one by > > > > the function e820_mark_nosave_range() in arch/x86_64/kernel/e82= 0.c that > > > > can be ported to i386 with no problems. However, we haven't fo= und that > > > > very useful, so far, since no one has ever reported any problem= s with > > > > the current approach, which is to save and restore them. > > > > > > Well, the following proof of concept patch fixes this issue for m= e. > > > Please notice that original version of e820_mark_nosave_range() c= ould > > > fail to exclude some areas due to alignment issues (exactly what = happened > > > to me on first try) so it still can explain your problem too. > > > > Great job, thanks for the patch! It looks good, so I'm going to fo= rward it > > for merging. > > >=20 > Please no; I'm currently testing slightly more polished version; I wi= ll send > it later. OK > Could anybody explain (or give pointer to) what happens which region = that is > not page-aligned? In particular, the very first one: >=20 > BIOS-e820: 0000000000000000 - 000000000009fc00 (usable) > BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved) >=20 > Will the kernel allocate partial page (how?) or will the kernel ignor= e last > (first) incomplete page? In the former case how those incomplete page= s can be > detected? Well, on x86_64, if I understand e820_register_active_regions() correct= ly, the partial pages won't be registered. Greetings, Rafael - To unsubscribe from this list: send the line "unsubscribe linux-acpi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html