On Mon, 26 Feb 2018, Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> wrote: > On Mon, Feb 26, 2018 at 03:45:51PM -0800, Azhar Shaikh wrote: >> SAGV handling is currently broken which can result in system hangs. >> Add a parameter to disable SAGV, till the SAGV handling is fixed. > > Not just handling of the limitations we have with SAGV is broken but > also probably some hidden DBUF config issue that is worst when SAGV > is enabled. > > But also the handling broken is not a good reason for the parameter > itself. But the good part of this is the ability to debug display > hard hangs issues with SAGV requirements. > > I'm in favor of the paramenter. We just need a different justification > here. *cringe* at adding a parameter to workaround issues. >> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104975 >> Signed-off-by: Azhar Shaikh <azhar.shaikh@xxxxxxxxx> >> --- >> drivers/gpu/drm/i915/i915_params.c | 3 +++ >> drivers/gpu/drm/i915/i915_params.h | 3 ++- >> drivers/gpu/drm/i915/intel_pm.c | 2 +- >> 3 files changed, 6 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c >> index 08108ce5be21..6aede52240b0 100644 >> --- a/drivers/gpu/drm/i915/i915_params.c >> +++ b/drivers/gpu/drm/i915/i915_params.c >> @@ -167,6 +167,9 @@ struct i915_params i915_modparams __read_mostly = { >> i915_param_named_unsafe(enable_dp_mst, bool, 0600, >> "Enable multi-stream transport (MST) for new DisplayPort sinks. (default: true)"); >> >> +i915_param_named_unsafe(disable_sagv, bool, 0600, >> + "Disable SAGV (default: false)"); >> + > > I understand that SAGV is default to enable and enabled by BIOS so we > actually need to disable it. > > However the name will cause the same old confusion as disable power well disable.... > > So I'm in favor of bool i915.enable_sagv defaults to enable > and use i915.enable_sagv=0 when we need to disable it. Agreed, if you must use a parameter. BR, Jani. -- Jani Nikula, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
