On Fri, Mar 13, 2015 at 1:46 PM, Eric Caruso <ejcaruso@xxxxxxxxxxxx> wrote: > On Fri, Mar 13, 2015 at 1:14 PM, Paulo Zanoni <przanoni@xxxxxxxxx> wrote: >> 2015-03-13 16:01 GMT-03:00 Daniel Vetter <daniel@xxxxxxxx>: >>> On Fri, Mar 13, 2015 at 7:10 PM, Eric Caruso <ejcaruso@xxxxxxxxxxxx> wrote: >>>> This patch allows userspace to toggle PSR through a debugfs interface. >>>> It adds functionality to write 0 or 1 to the existing >>>> i915_edp_psr_status file in order to change the relevant module >>>> parameter and enable/disable PSR. >>>> >>>> Previous upstream feedback did not like making it a connector property >>>> or putting it in sysfs because that would require API stability going >>>> forward. debugfs interfaces do not have this restriction. >>>> >>>> Signed-off-by: Eric Caruso <ejcaruso@xxxxxxxxxxxx> >>> >>> What do we need this for? debugfs is generally for debugging (where >>> the module option should be enough) and for testcases (which doesn't >>> seem to be the case here). >> >> What is wrong with "echo 1 > /sys/module/i915/parameters/enable_psr"? >> >>> -Daniel >>> -- >>> Daniel Vetter >>> Software Engineer, Intel Corporation >>> +41 (0) 79 365 57 48 - http://blog.ffwll.ch >>> _______________________________________________ >>> Intel-gfx mailing list >>> Intel-gfx@xxxxxxxxxxxxxxxxxxxxx >>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx >> >> >> >> -- >> Paulo Zanoni > > Forgive me if this is wrong, but updating the module parameter doesn't > change whether or not PSR is enabled immediately. You need to go through > intel_enable_ddi for this to take effect. indeed. > > We were using something like this for testing on Chromium OS, because > PSR would sometimes cause issues. This allows us to change the module > parameter and enable/disable PSR in one step. I like the idea. But I'd prefer a sysfs toggle interface though... > > The upstream feedback I mentioned was done about a year ago: > http://lists.freedesktop.org/archives/intel-gfx/2014-March/041896.html > It seemed to favor a debugfs knob for this. > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > http://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Rodrigo Vivi Blog: http://blog.vivi.eng.br _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
