FS#53281 - Changing power state of discrete GPU does not work in Dell XPS 9560 / Precision 5520
Attached to Project:
Arch Linux
Opened by Daniel Playfair Cal (hedgepigdaniel) - Sunday, 12 March 2017, 22:52 GMT
Last edited by Tobias Powalowski (tpowa) - Wednesday, 14 June 2017, 07:15 GMT
Opened by Daniel Playfair Cal (hedgepigdaniel) - Sunday, 12 March 2017, 22:52 GMT
Last edited by Tobias Powalowski (tpowa) - Wednesday, 14 June 2017, 07:15 GMT
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Details
Description:
Additional info: * linux 4.9.11-1 * bbswitch 0.8-64 Steps to reproduce: * Install Arch linux on a Dell XPS 9560 or Precision 5520 with a discrete nvidia GT 1050M GPU * Install bbswitch and attempt to enable or disable the discrete GPU * Notice that it doesn't work (reading /proc/acpi/bbswitch does not consistently reflect the intended change, more details in this kernel bug: https://bugzilla.kernel.org/show_bug.cgi?id=156341#c32) The conclusion from the kernel bug thread was to add the boot option acpi_rev_override=1 to the boot parameters, but this does not work on Arch because CONFIG_ACPI_REV_OVERRIDE_POSSIBLE is not set in the kernel configuration (because https://bugs.archlinux.org/task/47989) I can confirm that recompiling the Arch kernel with that flag set and then adding the boot parameter acpi_rev_override=1 fixes the issue and bbswitch works as expected. |
This task depends upon
Closed by Tobias Powalowski (tpowa)
Wednesday, 14 June 2017, 07:15 GMT
Reason for closing: Fixed
Additional comments about closing: on trunk
Wednesday, 14 June 2017, 07:15 GMT
Reason for closing: Fixed
Additional comments about closing: on trunk
Another option with the stock Arch kernel is to set boot parameters acpi_osi=! acpi_osi="Windows 2009", but it breaks touchpad and causes issues with the keyboard, so it is not preferable.
Enabling CONFIG_ACPI_REV_OVERRIDE_POSSIBLE for the stock kernel should not cause issues for other users, since it (as far as I can see) just allows the boot parameter to be optionally used. However, it would stop XPS 15 and XPS 13 (sound issues some models) users from having to keep compiling their own otherwise identical kernels just to be able to set the boot flag until the issues are resolved.
Could we re-enable this so users don't require a custom kernel for such a basic feature? From what I read, Ubuntu has this CONFIG enabled in its kernel.
https://bugzilla.kernel.org/show_bug.cgi?id=156341#c32
https://lkml.org/lkml/2017/2/27/531