On 2020-02-21 10:21, Chris Wilson wrote: > Quoting Martin Peres (2020-02-21 07:33:59) >> On 2020-02-20 19:41, Chris Wilson wrote: >>> Since we check before and then after each debugfs entry, we do not need >>> to check before each time as well. We will error out as soon as it does >>> fail, at all other times we know the system to be idle. >>> >>> No impact on runtime for glk (which apparently is one of the better >>> behaving systems). >>> >>> Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk> >>> Cc: Martin Peres <martin.pe...@linux.intel.com> >> >> I don't like this patch because the first read might not have the gpu >> suspended, and there shouldn't be much overhead in checking twice rather >> than once. >> >> What's your rationale here? > > We always do a check before after each file. We start in a known state, > and expect to be able to return to that suspended state, and the _real_ > guts of the test is that any device access is accounted for. > > assert(suspended) would be a better check for non-interference.
I would feel better with assert(suspended) added, but would it really speed anything up since I assume wait_for_suspended() should be instantaneous if we are already suspended, right? > >> To me, the issue is that some platforms suspend in milliseconds while >> some take seconds, and that might be indicative a real bug in the driver. > > Exactly. Good to hear :) > -Chris > _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
