[Intel-gfx] [PATCH] pm_rps: Improve file I/O and restore utilities

[Daniel Vetter]

On Fri, Jan 10, 2014 at 11:20:42AM -0600, jeff.mcgee at intel.com wrote:
> From: Jeff McGee <jeff.mcgee at intel.com>
> 
> Use unbuffered file I/O to simplify and ensure proper sysfs access.
> Bionic C library may not re-read a read-only file unless unbuffered,
> which results in failure to monitor changes in gt_cur_freq_mhz.
> 
> Adapt do_writeval to assert that no write error occurs when we expect
> none.
> 
> Expand use of restore_assert macro to ensure that original min/max
> frequencies are always in place after a test failure.

The above three changs should be split into three patches, so that in case
something blows up we don't have to dig out the test functionality changes
from the switch to raw io.

Also I think we should replace restore_assert with an igt cleanup handler.
Those are a bit more robust and will also clean up even when the test
process has caught a signal.

See igt_install_exit_handler. there's already plenty of examples all over
the tree.

Thanks, Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch