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. -- Best regards, Andrey Skvortsov
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