On Mon, Jun 13, 2016 at 12:07 PM, Andrey Skvortsov <andrej.skvortzov@xxxxxxxxx> wrote: > 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.acpidump.bin > >> > > > > >> > > > > 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. I have decided to revert commit 66b1ed5aa8dd25 as in principle other registers may be similarly affected on other systems. Thanks, Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
