From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jani Nikula Subject: Re: [PATCH] drm/i915: Add debug module option for VTd validation Date: Tue, 01 Apr 2014 11:14:08 +0300 Message-ID: <8738hxeab3.fsf@intel.com> References: <87eh1hee2y.fsf@intel.com> <1396337627-21554-1-git-send-email-daniel.vetter@ffwll.ch> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by gabe.freedesktop.org (Postfix) with ESMTP id 7CF766E517 for ; Tue, 1 Apr 2014 01:13:37 -0700 (PDT) In-Reply-To: <1396337627-21554-1-git-send-email-daniel.vetter@ffwll.ch> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: Intel Graphics Development Cc: Daniel Vetter List-Id: intel-gfx@lists.freedesktop.org On Tue, 01 Apr 2014, Daniel Vetter wrote: > VTd has a few too many "outright disable the damn thing" workarounds > accumulated and for validation we want a simple knob to make sure we > disable them all. > > Since this is for bdw+ validation and atm we don't have any > workarounds for bdw this option currently does nothing. So currently > this is just a placeholder to make sure reality will match with the > documented process for our validation people. > > v2: Fix up param description (Jani). > > v3: Actually git add ... *rolls eyes* ;) I'm really sorry I just spotted that one param desc and failed to do any proper review. So here's some bikeshedding. > > Cc: Jani Nikula > Cc: David Woodhouse > Signed-off-by: Daniel Vetter > --- > drivers/gpu/drm/i915/i915_drv.h | 1 + > drivers/gpu/drm/i915/i915_params.c | 4 ++++ > 2 files changed, 5 insertions(+) > > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h > index ff02225d5edd..610ff70f8609 100644 > --- a/drivers/gpu/drm/i915/i915_drv.h > +++ b/drivers/gpu/drm/i915/i915_drv.h > @@ -1925,6 +1925,7 @@ struct i915_params { > bool prefault_disable; > bool reset; > bool disable_display; > + bool disable_vtd_wa; > }; > extern struct i915_params i915 __read_mostly; > > diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c > index e1027cc5f0ee..d05a2afa17dc 100644 > --- a/drivers/gpu/drm/i915/i915_params.c > +++ b/drivers/gpu/drm/i915/i915_params.c > @@ -47,6 +47,7 @@ struct i915_params i915 __read_mostly = { > .invert_brightness = 0, > .disable_display = 0, > .enable_cmd_parser = 1, > + .disable_vtd_wa = 0, Gringe at initializing bools with ints. > }; > > module_param_named(modeset, i915.modeset, int, 0400); > @@ -149,6 +150,9 @@ MODULE_PARM_DESC(invert_brightness, > module_param_named(disable_display, i915.disable_display, bool, 0600); > MODULE_PARM_DESC(disable_display, "Disable display (default: false)"); > > +module_param_named(disable_vtd_wa, i915.disable_vtd_wa, bool, 0600); > +MODULE_PARM_DESC(disable_vtd_wa, "Disable all VT-d workarounds (default: false)"); > + Why negative? Why not enable_vtd_wa defaulting to true? The disable will lead to code like: if (!i915.disable_vtd_wa) instead of if (i915.enable_vtd_wa) Regardless of the bikeshedding, it's Reviewed-by: Jani Nikula > module_param_named(enable_cmd_parser, i915.enable_cmd_parser, int, 0600); > MODULE_PARM_DESC(enable_cmd_parser, > "Enable command parsing (1=enabled [default], 0=disabled)"); > -- > 1.8.5.2 > -- Jani Nikula, Intel Open Source Technology Center