I test the latest kernel in a HP nx5000, which includes the RTC fix. I observed some error message: Failed to acquire semaphore ACPI_MTX_HARDWARE After digging out, It appears 'acpi_install_fixed_event_handler' prepares to install RTC handler, and in the meantime a RTC interrupt is generated. Exactly the interrupt is invoked when ACPICA does: status = acpi_enable_event (event, 0); But I can't always reproduce it. Below steps is the more reliable reproduce steps, but it also can't be trust. 1. Set /proc/acpi/alarm. wait it timeout 2. reboot; Then we will see the error message.
Created attachment 4316 [details] debug patch I think we should clear event before try to enable event. Attached patch seems help my system (I didn't see the error message after apply it). But since I can't always reproduce the bug, it's hard to say if it's the fix.
Ok, I get the reliable reproduce steps: 1. Set /proc/acpi/alarm. wait it timeout Do step 1 for 3 times 2. reboot Then I always look at the error message: > osl-0958 [15] os_wait_semaphore : Failed to acquire semaphore [df7cc544|1|0], AE_TIME > utmisc-0729 [14] ut_acquire_mutex : Thread 0 could not acquire Mutex [ACPI_MTX_Hardware] AE_TIME > osl-0958 [15] os_wait_semaphore : Failed to acquire semaphore [df7cc544|1|0], AE_TIME > utmisc-0729 [14] ut_acquire_mutex : Thread 0 could not acquire Mutex [ACPI_MTX_Hardware] AE_TIME The patch in comment #1 indead fixes it for me. Please review the patch.
Reproduced this on a Toshiba laptop as well. Was also able to work around the error by reverting the patch in bug #1320 which enabled the wake-on-RTC feature. Applied patch in comment #1 to acpi-test tree.
shipped in 2.6.13-rc3 - closing