From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= Subject: Re: [PATCH v2 1/9] drm/i915: Remove superfluous NULL check Date: Fri, 4 Dec 2015 15:07:03 +0200 Message-ID: <20151204130703.GX4437@intel.com> References: <1448986198-3488-1-git-send-email-tiwai@suse.de> <1448986198-3488-2-git-send-email-tiwai@suse.de> <20151204121646.GU4437@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Takashi Iwai Cc: Libin Yang , alsa-devel@alsa-project.org, Mengdong Lin , Vinod Koul , intel-gfx@lists.freedesktop.org, Jani Nikula , Daniel Vetter , David Henningsson List-Id: intel-gfx@lists.freedesktop.org On Fri, Dec 04, 2015 at 01:54:56PM +0100, Takashi Iwai wrote: > On Fri, 04 Dec 2015 13:16:46 +0100, > Ville Syrj=E4l=E4 wrote: > > = > > On Tue, Dec 01, 2015 at 05:09:50PM +0100, Takashi Iwai wrote: > > > to_intel_crtc() always returns a non-NULL pointer. > > = > > Eh? to_intel_crtc(NULL) should return NULL or we might have tons of > > breakage on our hands. Or maybe the atomic work has gotten rid of that > > assumption, but at least we used to depend on that heavily. > = > Well, to_intel_crtc() has been always container_of() since the very > beginning of universe: > = > commit 79e539453b34e35f39299a899d263b0a1f1670bd > Author: Jesse Barnes > Date: Fri Nov 7 14:24:08 2008 -0800 > = > DRM: i915: add mode setting support > = > --- /dev/null > +++ b/drivers/gpu/drm/i915/intel_drv.h > .... > +#define to_intel_crtc(x) container_of(x, struct intel_crtc, base) > .... Yes, but = struct intel_crtc { struct drm_crtc base; ... } So offsetof(struct intel_crtc, base)=3D=3D0 and NULL-0 is still NULL. I once suggested that someone should add a compile time assert to make sure this always holds for us, but no one took the bait. > = > = > Takashi > = > > = > > > = > > > Signed-off-by: Takashi Iwai > > > --- > > > drivers/gpu/drm/i915/intel_audio.c | 4 ---- > > > 1 file changed, 4 deletions(-) > > > = > > > diff --git a/drivers/gpu/drm/i915/intel_audio.c b/drivers/gpu/drm/i91= 5/intel_audio.c > > > index 4dccd9b003a1..0c38cc6c82ae 100644 > > > --- a/drivers/gpu/drm/i915/intel_audio.c > > > +++ b/drivers/gpu/drm/i915/intel_audio.c > > > @@ -656,10 +656,6 @@ static int i915_audio_component_sync_audio_rate(= struct device *dev, > > > intel_dig_port =3D enc_to_dig_port(&intel_encoder->base); > > > if (port =3D=3D intel_dig_port->port) { > > > crtc =3D to_intel_crtc(intel_encoder->base.crtc); > > > - if (!crtc) { > > > - DRM_DEBUG_KMS("%s: crtc is NULL\n", __func__); > > > - continue; > > > - } > > > pipe =3D crtc->pipe; > > > break; > > > } > > > -- = > > > 2.6.3 > > = > > -- = > > Ville Syrj=E4l=E4 > > Intel OTC > > = -- = Ville Syrj=E4l=E4 Intel OTC