On Mon, Jan 18, 2016 at 2:25 PM, Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> wrote: > On Monday, January 18, 2016 12:52:53 PM Andy Lutomirski wrote: >> I'm running 4.4 with the pm+acpi-4.5-rc1-1 merged in. After pressing >> the backlight hotkeys a couple times, things start to break. Poking >> at hung thread stacks, it appears that calls to >> acpi_video_handles_brightness_key_presses never return. >> >> It appears that the culprit is: >> >> commit aecbd9b1bff6afbe349921b406b99d285b412820 >> Author: Adrien Schildknecht <adrien+dev@xxxxxxxxxxx> >> Date: Mon Jan 4 23:22:28 2016 +0100 >> >> ACPI / video: driver must be registered before checking for keypresses >> >> Reverting that patch makes my laptop work again. >> >> I don't know what that patch is trying to do, but it looks highly >> questionable to me. Why should an accessor wait for a potential >> different driver to register something? I see no guarantee that it >> will eve happen. >> >> This is a Dell XPS 13 9350. > > Should be fixed in my linux-next branch, can you please try that one? > To avoid churning my laptop tree too much, I cherry-picked: ACPI / video: Add disable_backlight_sysfs_if quirk for the Toshiba Satellite R830 ACPI / video: Revert "thinkpad_acpi: Use acpi_video_handles_brightness_key_presses()" ACPI / video: Document acpi_video_handles_brightness_key_presses() a bit ACPI / video: Fix using an uninitialized mutex / list_head in acpi_video_handles_brightness_key_presses() ACPI / video: Revert "ACPI / video: driver must be registered before checking for keypresses" The result seems to work. Are you planning on sending these for 4.5? --Andy -- 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
