On Friday, June 10, 2016 11:32:10 PM Andrey Skvortsov wrote: > > --IS0zKkzwUGydFO0o > Content-Type: text/plain; charset=utf-8 > Content-Disposition: inline > Content-Transfer-Encoding: quoted-printable > > 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_h= > w_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 B= > lock > (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-b= > it), but it's=20 > 1 (8-bit). > > The root of the problem seems to be not the commit 66b1ed5aa8dd25 itself, b= > ut 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? 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. 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
