Distribution: Debian testing Hardware Environment: TP 600X Software Environment: hacked DSDT (see Bug #4989), kernel patched with patches from Bug #5008 (ec burst mode), Bug #5035 (specific hotkey), Bug #5037 (S3 sleep hang workaround), booted with command line: BOOT_IMAGE=+three-patches ro root=305 idebus=66 apm=off acpi=force pci=noacpi console=ttyS0,115200 console=tty0 acpi_sleep=s3_bios ec_burst=1 Problem Description: Sometimes I cannot change the debug_level or debug_layer settings, whether I use 'echo -n' or 'echo' > /proc/acpi/debug_layer or /proc/acpi/debug_level. It's intermittent. I wasn't able to change either value, then I was able to a few times, and right now I cannot. Here's an example transcript of it failing: # cat /proc/acpi/debug_layer Description Hex SET ACPI_UTILITIES 0x00000001 [ ] ACPI_HARDWARE 0x00000002 [ ] ACPI_EVENTS 0x00000004 [ ] ACPI_TABLES 0x00000008 [ ] ACPI_NAMESPACE 0x00000010 [*] ACPI_PARSER 0x00000020 [ ] ACPI_DISPATCHER 0x00000040 [ ] ACPI_EXECUTER 0x00000080 [ ] ACPI_RESOURCES 0x00000100 [ ] ACPI_CA_DEBUGGER 0x00000200 [ ] ACPI_OS_SERVICES 0x00000400 [ ] ACPI_CA_DISASSEMBLER 0x00000800 [ ] ACPI_COMPILER 0x00001000 [ ] ACPI_TOOLS 0x00002000 [ ] ACPI_ALL_DRIVERS 0xFFFF0000 [ ] -- debug_layer = 0x00000010 (* = enabled, - = partial) # echo -n 0x4100000 > debug_layer # cat /proc/acpi/debug_layer Description Hex SET ACPI_UTILITIES 0x00000001 [ ] ACPI_HARDWARE 0x00000002 [ ] ACPI_EVENTS 0x00000004 [ ] ACPI_TABLES 0x00000008 [ ] ACPI_NAMESPACE 0x00000010 [*] ACPI_PARSER 0x00000020 [ ] ACPI_DISPATCHER 0x00000040 [ ] ACPI_EXECUTER 0x00000080 [ ] ACPI_RESOURCES 0x00000100 [ ] ACPI_CA_DEBUGGER 0x00000200 [ ] ACPI_OS_SERVICES 0x00000400 [ ] ACPI_CA_DISASSEMBLER 0x00000800 [ ] ACPI_COMPILER 0x00001000 [ ] ACPI_TOOLS 0x00002000 [ ] ACPI_ALL_DRIVERS 0xFFFF0000 [ ] -- debug_layer = 0x00000010 (* = enabled, - = partial) Steps to reproduce: Have never seen this happen before, so don't know if I can reproduce it. But this is also the first time I've booted with the testing kernel and ec_burst=1 so maybe there's a culprit in ec_burst or in one of the patches.
Sorry I must be smoking dope. echo -n 0x4100000 > debug_layer was not working because I didn't give the full path /proc/acpi/debug_layer (so it worked when I had cd'ed to /proc/acpi but not otherwise).