Add Cc. to platform-driver-x86 and linux-acpi Hi Baptiste 於 日，2011-12-04 於 17:07 +0100，Baptiste Jonglez 提到： > Hi, > > I've got a lot of troubles with a dual-LVDS Acer laptop (it doesn't > have a keyboard, but two displays with touchscreens) > > The Intel GPU is integrated into the Core i5-480M CPU: it's a bit > older than Sandybridge, as it seems to be based on the Arrandale > micro-architecture. > > In the BIOS, both displays work fine; but as soon as the kernel boots > up, the second display (i.e. the one where you usually find a > keyboard) is turned off. The main display works as expected. > > xrandr reports two LVDS displays: LVDS1, which is connected, and > LVDS2, which is marked as "disconnected". No matter what I tried, I > can't bring that second display up. > > During the boot, just after the drm is set up, the following message > shows up: > > [drm:intel_dsm_pci_probe] *ERROR* failed to get supported _DSM functions > > (attached is the relevant part of dmesg [1]) > > Have no idea for this _DSM error, need help from drm and acpi experts. > > I then tried booting with "video=LVDS-2:e". The same message shows up > while booting, with these two following: > > [drm:drm_crtc_helper_set_config] *ERROR* failed to set mode on [CRTC:4] > fbcon_init: detected unhandled fb_set_par error, error code -22 > > (attached is the relevant part of dmesg [2]) > > With that kernel command line forcing LVDS2, the > "drm_crtc_helper_set_config" error shows up each time I switch tty; > additionally, X does not want to start anymore (spewing out the > aforementioned error multiple times before giving up) > > > I'm currently using the latest 3.2 kernel from linus' tree > (af968e29acd91ebeb4224e899202c46c93171ecd), but the behavior was > similar with a vanilla 3.1.2. > > > Other notes about this issue: > > - with an Ubuntu 2.6.35 kernel, the second display is on but > flickering (with the picture distorted like an old analog TV...). > The main display is working fine, as always. > > - with an Archlinux 2.6.37.5 kernel, the behavior is the same as with > 3.2, the main display is ok and the second one is off. > > - I did succeed, only once and out of pure luck, to get the second > screen to work with the 3.1.2 kernel. I haven't been able to > reproduce that... I had booted with "video=LVDS-2:e" and let the > laptop running ; pressing a key a few hours later turned back > *both* displays on (the main display had been turned off by DPMS, > and the second, well, was off from the start, as always) > While not very helpful, it shows that it's definitely possible. > What does Windows platform's behavior? Does there have any physical key that can turn on/off the second LVDS on Windows? > - there are a some unhandled WMI events logged from the acer-wmi > module [3] when closing the lid, opening it, and most importantly, > when the (main) screen is turned on or off by DPMS. > I will look at your dsdt and log from acer-wmi then try to improve acer-wmi. > > > What do you think? I haven't really succeeded in nailing the source of > the issue down, but here are a few possibilities I'm thinking of: > > - the driver is not aware it can drive two LVDS displays (not very > likely, and it has worked once, see above) > > - there is some kind of switch that is able to turn the second screen > on or off (I'm thinking of something like rfkill). If so, it looks > like something non-standard and undocumented. This would explain > the WMI events (see the last note above) > What's the behavior of Windows? > - buggy ACPI implementation. I tried to extract then recompile the > DSDT [4], and iasl spews out 17 errors and 12 warnings. Also worth > noticing is that line in dmesg: > "pci0000:00: ACPI _OSC request failed (AE_ERROR), returned control mask: 0x1d" > > > The Archlinux userland is: > - libdrm 2.4.27 > - xorg-server 1.11.2 > - intel-dri 7.11.1 > - xf86-video-intel 2.17.0 > > > Please let me know if there are any other details I should provide. > Regards, > Baptiste > > Attachments: > [1] dmesg-DSM-functions.log - drm errors when booting normally > [2] dmesg-video-lvds2.log - drm errors when forcing LVDS2 on the cmdline > [3] acer_wmi.log - WMI events that land in dmesg > [4] dsdt - /sys/firmware/acpi/tables/DSDT Please also attached on dmidecode log. Thank's a lot! Joey Lee -- 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
