[PATCH 0/3] ACPI / debugger: Add kernel flushing support

From: Lv Zheng
Date: Wed Jul 13 2016 - 22:52:40 EST

AML debugger is implemented in the kernel as a character device located in
the debugfs. Currently, when its batch mode is used, the userspace tool
needs to flush the logs/prompts remained in the kernel output buffer, this
is implemented in an inefficient way in the userspace by polling the IO and
reading everything out.

This patch introduces a kernel space flushing support, so that userspace
can invoke fsync() to put the driver into a state waiting for new commands,
all kernel space logs/prompts will be automatically discarded by fsync().

Lv Zheng (3):
debugfs: Add .fsync() callback proxy support
ACPI / debugger: Add kernel flushing support
tools/power/acpi/acpidbg: Use new flushing mechanism

drivers/acpi/acpi_dbg.c | 94 ++++++++++++++++++++++++++++--
fs/debugfs/file.c | 6 ++
tools/power/acpi/tools/acpidbg/acpidbg.c | 49 ++--------------
3 files changed, 101 insertions(+), 48 deletions(-)