On Mon, Apr 10, 2017 at 05:20:32PM +0200, Michal Wajdeczko wrote: > On Mon, Apr 10, 2017 at 04:02:05PM +0100, Chris Wilson wrote: > > Allow the caller to use the fast_timeout_us to specify how long to wait > > within the atomic section, rather than transparently switching to a > > sleeping loop for larger values. This is required as some callsites may > > need a long wait and are in an atomic section. > > > > Signed-off-by: Chris Wilson <[email protected]> > > Cc: Michal Wajdeczko <[email protected]> > > Cc: Joonas Lahtinen <[email protected]> > > --- > > drivers/gpu/drm/i915/intel_uncore.c | 11 ++++++----- > > 1 file changed, 6 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/intel_uncore.c > > b/drivers/gpu/drm/i915/intel_uncore.c > > index eb38392a2435..53c8457869f6 100644 > > --- a/drivers/gpu/drm/i915/intel_uncore.c > > +++ b/drivers/gpu/drm/i915/intel_uncore.c > > @@ -1601,7 +1601,7 @@ static int gen6_reset_engines(struct drm_i915_private > > *dev_priv, > > * > > * Otherwise, the wait will timeout after @slow_timeout_ms milliseconds. > > * For atomic context @slow_timeout_ms must be zero and @fast_timeout_us > > - * must be not larger than 10 microseconds. > > + * must be not larger than 20,0000 microseconds. > > So we don't enforce this any more ?
I considered adding a GEM_BUG_ON / GEM_WARN_ON, but really just not listening to them and hitting the sleep was my answer to sillyness. Atomic spinning for 20ms is not acceptable. :| > > * Note that this routine assumes the caller holds forcewake asserted, it > > is > > * not suitable for very long waits. See intel_wait_for_register() if you > > @@ -1623,16 +1623,17 @@ int __intel_wait_for_register_fw(struct > > drm_i915_private *dev_priv, > > int ret; > > > > /* Catch any overuse of this function */ > > - might_sleep_if(fast_timeout_us > 10 || slow_timeout_ms); > > + might_sleep_if(slow_timeout_ms); > > > > - if (fast_timeout_us > 10) > > - ret = _wait_for(done, fast_timeout_us, 10); > > - else > > + ret = -ETIMEDOUT; > > + if (fast_timeout_us && fast_timeout_us < 20000) > > ret = _wait_for_atomic(done, fast_timeout_us, 0); > > if (ret) > > ret = wait_for(done, slow_timeout_ms); > > What if someone passes fast=20001us and slow=0ms ? > Maybe like this: > > might_sleep_if(fast_timeout_us > 20000 || slow_timeout_ms); > > if (fast_timeout_us && fast_timeout_us < 20000) > ret = _wait_for_atomic(done, fast_timeout_us, 0); > else > slow_timeout_ms += fast_timeout_us/1000; No. Just shoot it down in review. -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
