Hi, > From: Andrey Skvortsov [mailto:andrej.skvortzov@xxxxxxxxx] > Subject: Re: acpi: broken suspend to RAM with v4.7-rc1 > > On 24 Jun, Zheng, Lv wrote: > > Hi, > > > > > From: Andrey Skvortsov [mailto:andrej.skvortzov@xxxxxxxxx] > > > Subject: Re: acpi: broken suspend to RAM with v4.7-rc1 > > > > > > Hi Lv, > > > > > > On 13 Jun, Zheng, Lv wrote: > > > > > From: linux-acpi-owner@xxxxxxxxxxxxxxx [mailto:linux-acpi- > > > > > owner@xxxxxxxxxxxxxxx] On Behalf Of Rafael J. Wysocki > > > > > Subject: Re: acpi: broken suspend to RAM with v4.7-rc1 > > > > > > > > > > On Saturday, June 11, 2016 01:49:22 PM Andrey Skvortsov wrote: > > > > > > On 10 Jun, Rafael J. Wysocki wrote: > > > > > > > On Friday, June 10, 2016 11:32:10 PM Andrey Skvortsov wrote: > > > > > > > > Hi, > > > > > > > > > > > > > > > > On my laptop (DELL Vostro 1500) in v4.7-rc1 is broken > suspend > > > to RAM. > > > > > > > > Laptop doesn't finish suspend to RAM process (disks are off, > but > > > > > > > > WiFi and Power LEDs are still on). The only way to get it out of > > > > > > > > this state, is to turn the power off. > > > > > > > > > > > > > > > > I've bisected the issue to commit 66b1ed5aa8dd25 > > > > > > > > [ACPICA: ACPI 2.0, Hardware: Add access_width/bit_offset > > > support > > > > > > > > for acpi_hw_write()]. > > > > > > > > > > > > > > > > If I revert this commit in v4.7-rc1 (or v4.7-rc2), suspend to > RAM > > > > > > > > is working again. > > > > > > > > > > > > > > > > The cause of this problem is that after this commit write to > > > PM1A > > > > > > > > Control Block (16-bit register) is done using two 8-bit writes. > > > > > > > > If I force this write to be 16-bit, then all is working as before. > > > > > > > > > > > > > > > > To get it working 'access_width' for PM1A Control Block > needs to > > > > > > > > be 2 (16-bit), but it's 1 (8-bit). > > > > [Lv Zheng] > > > > Could you send me the acpidump of the machine? > > > Here it is > > > > https://dl.dropboxusercontent.com/u/24023626/dell_vostro_1500.acpid > > > ump.bin > > [Lv Zheng] > > I've been trying to download it these days but all failed. > > Could you send an off-list email to me with this attached? > Strange. I've check now. The link above is working, but I see that > part of the link above is moved to the next line. [Lv Zheng] Maybe this is just because of ISP firewall. > Anyway I resend you all files off-list. [Lv Zheng] Great! > > > > > > > > > > The root of the problem seems to be not the commit > > > > > 66b1ed5aa8dd25 > > > > > > > > itself, but the ACPI tables in BIOS where wrong access_width > > > > > > > > comes from. I fixed problem in FACP table, put it in initrd to > > > > > > > > override FACP table from BIOS. This fixed the issue, suspend > to > > > > > > > > RAM is working now again. > > > > > > > > > > > > > > > > But I'm not sure whether is this proper fix for this problem. > > > > > > > > Is there any place in the kernel, where such ACPI quirks are > placed? > > > > [Lv Zheng] > > > > My question would be: > > > > Does Windows behave correctly for this table? > > > Yes, suspend to RAM is working under Windows Vista. > > > IIRC it worked under Windows XP too. > > > > > > > However there is a real case showing that there are real tables need > us to > > > correctly support BitWidth/BitOffset. > > > > Here is the information for you to refer: > > > > > http://permalink.gmane.org/gmane.linux.kernel.commits.head/313870 > > > > > > > > > > > > > > > > > > Well, if the commit in question caused a problem to happen for > > > you, > > > > > > > it also might cause similar problems to happen elsewhere. > > > > > > > > > > > > > > It looks like we'll need to revert that commit. > > > > > > Hi, > > > > > > > > > > > > or maybe to reset access_width AnyAcc from FACP table only for > > > PM1A > > > > > > control register or even for all registers? This will fix the issue too. > > > > > > > > > > That's a good idea actually. > > > > > > > > > > > diff --git a/drivers/acpi/acpica/tbfadt.c > > > > > > b/drivers/acpi/acpica/tbfadt.c index 6208069..a476e94 100644 > > > > > > --- a/drivers/acpi/acpica/tbfadt.c > > > > > > +++ b/drivers/acpi/acpica/tbfadt.c > > > > > > @@ -714,7 +714,14 @@ static void > > > acpi_tb_setup_fadt_registers(void) > > > > > > } > > > > > > } > > > > > > } > > > > > > > > > > > > + /* > > > > > > + * Reset access_width in the GAS for PM1A control register > to > > > > > > + * undefined value. Because in some cases this field contains > > > > > > + * wrong value. > > > > > > + */ > > > > > > + acpi_gbl_FADT.xpm1a_control_block.access_width = 0; > > > > > > > > > > OK, let's see what Bob and Lv think about that. > > > > [Lv Zheng] > > > > There is a commit in 4.7-rc2: > > > > > > > > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id= > > > 7f9bef9d > > > > Have you tried if the problem still exists in 4.7-rc2? > > > I've just tried v4.7-rc3. It contains commit 7f9bef9d and the problem > > > exists there too. > > [Lv Zheng] > > IMO, for the time being, you can use quirks. > > Booting your kernel with the following parameters: > > > > acpi=rsdt > > Or > > acpi_force_32bit_fadt_addr > > Or > > Both > > Rafael reverted commit, so I'm ok now. > > Actually acpi_force_32bit_fadt_addr will not help here, because it's take > effect only if address64 != address32. But here these addresses are > the same, therefore access_width is taken from extended address. > > http://lxr.free-electrons.com/source/drivers/acpi/acpica/tbfadt.c#L576 [Lv Zheng] In addition to the address check, we may add access width check here. I need to check this with the decision makers. > > > acpi=rsdt helps. Thanks for the information about this option. I > missed it, when I read documentation. [Lv Zheng] Great to know that at least 1 quirk works. Back to this bug, it seems we should use fixed access_width for some pre-defined PM registers. Thanks and best regards -Lv ��.n��������+%������w��{.n�����{�����ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f
