From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C33DBC49EA6 for ; Thu, 24 Jun 2021 09:08:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A3671613F0 for ; Thu, 24 Jun 2021 09:08:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229928AbhFXJKT (ORCPT ); Thu, 24 Jun 2021 05:10:19 -0400 Received: from smtp-out1.suse.de ([195.135.220.28]:36178 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229918AbhFXJKS (ORCPT ); Thu, 24 Jun 2021 05:10:18 -0400 Received: from imap.suse.de (imap-alt.suse-dmz.suse.de [192.168.254.47]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 085B921966; Thu, 24 Jun 2021 09:07:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1624525679; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=rKL9mP48io+APDMklw5yU/nTFyyLtllrHvhRByxGfgM=; b=Fa003aqPNfKvMmB5gj67Z2b+vADOqXwJZbsZa1wLiyJFEYxd8Ib341pE3+k1q3LB/3NTPM sec4L/zG58xoB1lJqeaGcoJORFmdA4MYlT10zNcfBOK9OQqTDe4HPy2ViRmxXEaOVhWpeB stgCohp2fTLc+re6z5B7wGsQj3RuBdw= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1624525679; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=rKL9mP48io+APDMklw5yU/nTFyyLtllrHvhRByxGfgM=; b=5fbRrwXqzrlBotN6vVs6nYUPpayauPPnI+y3I6tTE09d75iLijxUx+ydMD0QEa5X+6VQch gQMq4UauX+vXn3AA== Received: from imap3-int (imap-alt.suse-dmz.suse.de [192.168.254.47]) by imap.suse.de (Postfix) with ESMTP id D3DC011A97; Thu, 24 Jun 2021 09:07:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1624525678; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=rKL9mP48io+APDMklw5yU/nTFyyLtllrHvhRByxGfgM=; b=qka1M/+/Q0elb+Z4f6NaP+BgHuSA/yV87SJKUK7fBN5PWNEmX+fCZcno/5kvg/PzTE44iv joOoo0J1V3O+yOBF1zFmhwUrUs2dy9UjZf9K1YAFsRlSIR/viSN1/anfeuQcykgILCWH0K 16EhnP2e/GNrZU++exd36UAeNj2qNMU= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1624525678; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=rKL9mP48io+APDMklw5yU/nTFyyLtllrHvhRByxGfgM=; b=XNZZ2ccXjd52Zfc2lfinuyEZHBLa2WF7fIMYqmaGxOEk8UiNOL4HuWXLk8lyaE0Mmw9X8C niNIquqh21hULJCQ== Received: from director2.suse.de ([192.168.254.72]) by imap3-int with ESMTPSA id GA8HMm1L1GANNwAALh3uQQ (envelope-from ); Thu, 24 Jun 2021 09:07:57 +0000 Subject: Re: [PATCH v3 04/27] drm: Don't test for IRQ support in VBLANK ioctls To: Jani Nikula , daniel@ffwll.ch, airlied@linux.ie, alexander.deucher@amd.com, christian.koenig@amd.com, Xinhui.Pan@amd.com, james.qian.wang@arm.com, liviu.dudau@arm.com, mihail.atanassov@arm.com, brian.starkey@arm.com, maarten.lankhorst@linux.intel.com, mripard@kernel.org, inki.dae@samsung.com, jy0922.shim@samsung.com, sw0312.kim@samsung.com, kyungmin.park@samsung.com, krzysztof.kozlowski@canonical.com, xinliang.liu@linaro.org, tiantao6@hisilicon.com, john.stultz@linaro.org, kong.kongxinwei@hisilicon.com, puck.chen@hisilicon.com, laurentiu.palcu@oss.nxp.com, l.stach@pengutronix.de, p.zabel@pengutronix.de, shawnguo@kernel.org, s.hauer@pengutronix.de, kernel@pengutronix.de, festevam@gmail.com, linux-imx@nxp.com, chunkuang.hu@kernel.org, matthias.bgg@gmail.com, bskeggs@redhat.com, tomba@kernel.org, hjc@rock-chips.com, heiko@sntech.de, benjamin.gaignard@linaro.org, yannick.fertre@foss.st.com, philippe.cornu@foss.st.com, mcoquelin.stm32@gmail.com, alexandre.torgue@foss.st.com, wens@csie.org, jernej.skrabec@gmail.com, thierry.reding@gmail.com, jonathanh@nvidia.com, jyri.sarha@iki.fi, emma@anholt.net, linux-graphics-maintainer@vmware.com, zackr@vmware.com, hyun.kwon@xilinx.com, laurent.pinchart@ideasonboard.com, michal.simek@xilinx.com, rodrigo.vivi@intel.com, linux@armlinux.org.uk, kieran.bingham+renesas@ideasonboard.com, rodrigosiqueiramelo@gmail.com, melissa.srw@gmail.com, hamohammed.sa@gmail.com Cc: linux-samsung-soc@vger.kernel.org, nouveau@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-stm32@st-md-mailman.stormreply.com, linux-rockchip@lists.infradead.org, linux-mediatek@lists.infradead.org, amd-gfx@lists.freedesktop.org, Daniel Vetter , linux-tegra@vger.kernel.org, linux-sunxi@lists.linux.dev, linux-arm-kernel@lists.infradead.org References: <20210624072916.27703-1-tzimmermann@suse.de> <20210624072916.27703-5-tzimmermann@suse.de> <87im23u1ok.fsf@intel.com> <877dijtzl2.fsf@intel.com> From: Thomas Zimmermann Message-ID: Date: Thu, 24 Jun 2021 11:07:57 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <877dijtzl2.fsf@intel.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="Yy3WbyUimc1Hxu4dvJZCfzpxTV3jVapRO" Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --Yy3WbyUimc1Hxu4dvJZCfzpxTV3jVapRO Content-Type: multipart/mixed; boundary="4JbZC3NkmBgthQugAZppQ3TwC7sIXD4e6"; protected-headers="v1" From: Thomas Zimmermann To: Jani Nikula , daniel@ffwll.ch, airlied@linux.ie, alexander.deucher@amd.com, christian.koenig@amd.com, Xinhui.Pan@amd.com, james.qian.wang@arm.com, liviu.dudau@arm.com, mihail.atanassov@arm.com, brian.starkey@arm.com, maarten.lankhorst@linux.intel.com, mripard@kernel.org, inki.dae@samsung.com, jy0922.shim@samsung.com, sw0312.kim@samsung.com, kyungmin.park@samsung.com, krzysztof.kozlowski@canonical.com, xinliang.liu@linaro.org, tiantao6@hisilicon.com, john.stultz@linaro.org, kong.kongxinwei@hisilicon.com, puck.chen@hisilicon.com, laurentiu.palcu@oss.nxp.com, l.stach@pengutronix.de, p.zabel@pengutronix.de, shawnguo@kernel.org, s.hauer@pengutronix.de, kernel@pengutronix.de, festevam@gmail.com, linux-imx@nxp.com, chunkuang.hu@kernel.org, matthias.bgg@gmail.com, bskeggs@redhat.com, tomba@kernel.org, hjc@rock-chips.com, heiko@sntech.de, benjamin.gaignard@linaro.org, yannick.fertre@foss.st.com, philippe.cornu@foss.st.com, mcoquelin.stm32@gmail.com, alexandre.torgue@foss.st.com, wens@csie.org, jernej.skrabec@gmail.com, thierry.reding@gmail.com, jonathanh@nvidia.com, jyri.sarha@iki.fi, emma@anholt.net, linux-graphics-maintainer@vmware.com, zackr@vmware.com, hyun.kwon@xilinx.com, laurent.pinchart@ideasonboard.com, michal.simek@xilinx.com, rodrigo.vivi@intel.com, linux@armlinux.org.uk, kieran.bingham+renesas@ideasonboard.com, rodrigosiqueiramelo@gmail.com, melissa.srw@gmail.com, hamohammed.sa@gmail.com Cc: linux-samsung-soc@vger.kernel.org, nouveau@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-stm32@st-md-mailman.stormreply.com, linux-rockchip@lists.infradead.org, linux-mediatek@lists.infradead.org, amd-gfx@lists.freedesktop.org, Daniel Vetter , linux-tegra@vger.kernel.org, linux-sunxi@lists.linux.dev, linux-arm-kernel@lists.infradead.org Message-ID: Subject: Re: [PATCH v3 04/27] drm: Don't test for IRQ support in VBLANK ioctls References: <20210624072916.27703-1-tzimmermann@suse.de> <20210624072916.27703-5-tzimmermann@suse.de> <87im23u1ok.fsf@intel.com> <877dijtzl2.fsf@intel.com> In-Reply-To: <877dijtzl2.fsf@intel.com> --4JbZC3NkmBgthQugAZppQ3TwC7sIXD4e6 Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: quoted-printable Hi Am 24.06.21 um 10:51 schrieb Jani Nikula: > On Thu, 24 Jun 2021, Thomas Zimmermann wrote: >> Hi >> >> Am 24.06.21 um 10:06 schrieb Jani Nikula: >>> On Thu, 24 Jun 2021, Thomas Zimmermann wrote: >>>> diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vbla= nk.c >>>> index 3417e1ac7918..10fe16bafcb6 100644 >>>> --- a/drivers/gpu/drm/drm_vblank.c >>>> +++ b/drivers/gpu/drm/drm_vblank.c >>>> @@ -1748,8 +1748,16 @@ int drm_wait_vblank_ioctl(struct drm_device *= dev, void *data, >>>> unsigned int pipe_index; >>>> unsigned int flags, pipe, high_pipe; >>>> =20 >>>> - if (!dev->irq_enabled) >>>> - return -EOPNOTSUPP; >>>> +#if defined(CONFIG_DRM_LEGACY) >>>> + if (unlikely(drm_core_check_feature(dev, DRIVER_LEGACY))) { >>>> + if (!dev->irq_enabled) >>>> + return -EOPNOTSUPP; >>>> + } else /* if DRIVER_MODESET */ >>>> +#endif >>>> + { >>>> + if (!drm_dev_has_vblank(dev)) >>>> + return -EOPNOTSUPP; >>>> + } >>> >>> Sheesh I hate this kind of inline #ifdefs. >>> >>> Two alternate suggestions that I believe should be as just efficient:= >> >> Or how about: >> >> static bool drm_wait_vblank_supported(struct drm_device *dev) >> >> { >> >> if defined(CONFIG_DRM_LEGACY) >> if (unlikely(drm_core_check_feature(dev, DRIVER_LEGACY))) >> >> return dev->irq_enabled; >> >> #endif >> return drm_dev_has_vblank(dev); >> >> } >> >> >> ? >> >> It's inline, but still readable. >=20 > It's definitely better than the original, but it's unclear to me why > you'd prefer this over option 2) below. I guess the only reason I can > think of is emphasizing the conditional compilation. However, > IS_ENABLED() is widely used in this manner specifically to avoid inline= > #if, and the compiler optimizes it away. It's simply more readable to me as the condition is simpler. But option=20 2 is also ok. Best regards Thomas >=20 > BR, > Jani. >=20 >=20 >> >> Best regards >> Thomas >> >>> >>> 1) The more verbose: >>> >>> #if defined(CONFIG_DRM_LEGACY) >>> static bool drm_wait_vblank_supported(struct drm_device *dev) >>> { >>> if (unlikely(drm_core_check_feature(dev, DRIVER_LEGACY))) >>> return dev->irq_enabled; >>> else >>> return drm_dev_has_vblank(dev); >>> } >>> #else >>> static bool drm_wait_vblank_supported(struct drm_device *dev) >>> { >>> return drm_dev_has_vblank(dev); >>> } >>> #endif >>> >>> 2) The more compact: >>> >>> static bool drm_wait_vblank_supported(struct drm_device *dev) >>> { >>> if (IS_ENABLED(CONFIG_DRM_LEGACY) && unlikely(drm_core_check_featur= e(dev, DRIVER_LEGACY))) >>> return dev->irq_enabled; >>> else >>> return drm_dev_has_vblank(dev); >>> } >>> >>> Then, in drm_wait_vblank_ioctl(). >>> >>> if (!drm_wait_vblank_supported(dev)) >>> return -EOPNOTSUPP; >>> >>> The compiler should do the right thing without any explicit inline >>> keywords etc. >>> >>> BR, >>> Jani. >>> >>>> =20 >>>> if (vblwait->request.type & _DRM_VBLANK_SIGNAL) >>>> return -EINVAL; >>>> @@ -2023,7 +2031,7 @@ int drm_crtc_get_sequence_ioctl(struct drm_dev= ice *dev, void *data, >>>> if (!drm_core_check_feature(dev, DRIVER_MODESET)) >>>> return -EOPNOTSUPP; >>>> =20 >>>> - if (!dev->irq_enabled) >>>> + if (!drm_dev_has_vblank(dev)) >>>> return -EOPNOTSUPP; >>>> =20 >>>> crtc =3D drm_crtc_find(dev, file_priv, get_seq->crtc_id); >>>> @@ -2082,7 +2090,7 @@ int drm_crtc_queue_sequence_ioctl(struct drm_d= evice *dev, void *data, >>>> if (!drm_core_check_feature(dev, DRIVER_MODESET)) >>>> return -EOPNOTSUPP; >>>> =20 >>>> - if (!dev->irq_enabled) >>>> + if (!drm_dev_has_vblank(dev)) >>>> return -EOPNOTSUPP; >>>> =20 >>>> crtc =3D drm_crtc_find(dev, file_priv, queue_seq->crtc_id); >>> >=20 --=20 Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Maxfeldstr. 5, 90409 N=C3=BCrnberg, Germany (HRB 36809, AG N=C3=BCrnberg) Gesch=C3=A4ftsf=C3=BChrer: Felix Imend=C3=B6rffer --4JbZC3NkmBgthQugAZppQ3TwC7sIXD4e6-- --Yy3WbyUimc1Hxu4dvJZCfzpxTV3jVapRO Content-Type: application/pgp-signature; name="OpenPGP_signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="OpenPGP_signature" -----BEGIN PGP SIGNATURE----- wsF5BAABCAAjFiEExndm/fpuMUdwYFFolh/E3EQov+AFAmDUS20FAwAAAAAACgkQlh/E3EQov+Cd sQ//WrJ+cTjeCic8XWKP/6B1g/HO+aPRrvY0ktdf5gWjTVO6YN/FUVYp01LvOH8E1lh+mUmOWXlH 6sTbGXnxD39Kch9JuZqlVwVDjG+SFSNcwJtHHF4D93/sMMgf0C00N0dUwPEFARmqTu091Ya/R3fI 6iTBwu1GDLEcHDVaw5asnzmmDY9mMr7GIiJ4Kcy9I9fsdNybxG+P6Em3pMTBUlOFN6N4/GHrqs7I MjCvfDylb5jXxjPNMxQIeaevOwIi+xPTIZwGIeVdEhIpY6GHe8HKWFSqV2saCb9AoHW7vkNs0Tig ol8QFs1B/Yau/K39PCoRg1F8Y4nJaZfKL7JCHh0/bhhetCas1X4j8m1Y+jGPHIXFCh6orFNIqT+v J05PwfQ0vIz6bmxPxPt+KsHyf2RaYP6u5MPjfDICbAx1DPygVNuJLa+cUstqxoDqnPDNsK8a/s7b 1MitJWn6UOhnwzkXomyZcKTxvRzZqFy0nAcbGYQyGmZHg7hW1ylSuuWddE5a3wFgXY2yN4GwUARa t3F4HqZ+cFDwQJrxZ7Lev/rHSEL+IduPHzjfun+HVUzuqk2X/n/7qrll6ne0HOmaTLX19qRbMsZp NsZn3eCBnJbhcNS6NJ8CA6iMkBSb3oYkXDafmo8zZ1rbKVLsMJxHeaa/x9f79Ooa24VXjdRx3g0o EqM= =Jf7v -----END PGP SIGNATURE----- --Yy3WbyUimc1Hxu4dvJZCfzpxTV3jVapRO--