From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-6.1 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 212907D161 for ; Tue, 29 Jan 2019 19:26:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728439AbfA2T0m (ORCPT ); Tue, 29 Jan 2019 14:26:42 -0500 Received: from mail-yw1-f65.google.com ([209.85.161.65]:36514 "EHLO mail-yw1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726852AbfA2T0l (ORCPT ); Tue, 29 Jan 2019 14:26:41 -0500 Received: by mail-yw1-f65.google.com with SMTP id i73so8654707ywg.3 for ; Tue, 29 Jan 2019 11:26:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=poorly.run; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=GcukgBXEHQSQGkc3mdvEQKq+keUsB3n7RVA/njAR1oA=; b=KTDHD8hje5lYLTpYBI3dml5mFGRreS5vVdo9uVy7qZmLm/ym3R4mR4TRt8zbUh+JcA b2FCWk6dFYrhFpU4groVV6gIguBUHFvNWyKPT6f5T+YDRSNTYuG3AR4a7uyLKfDUtvzW i9VNYb4ImDgslnxmkS8UDzGwOo+aHqi3JaEfPpvXQW3y0x7i57K5nRtEYpS/89hoZAAy R3mxryDyqlrKmSsyqYSORvhGspBdpvO7CyoPOX2eF0/qv6enR1lbGn0ilztlEv4uN3Sv mPKzLlE2ZLL7OeEoOZo79X3kRMB6JEVHwVzssG+bUTlXFWatD95WlDOD2SWagBs73PhC H6vA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=GcukgBXEHQSQGkc3mdvEQKq+keUsB3n7RVA/njAR1oA=; b=XdA7lgEoS92L/SJJ9tMrn1CprHDB9Few+xrwik0eWGw4XyvrDQiQSOxa5QF1oJFl54 WEsVMH2RazesUptdiqOUPxFi5m0omhxojpc8TXA1decbAuK5V7SGoWV2Kh0tqNMoZccK CE2GMXXhw0OflFU7QnmY+WJpEWAkkXuDCf1/jowqAZycyA7kC/zZvgunEaGPtUppZSgL Jqhf20jyj78KT9NoyF7BxFu8gl36ZKBvv/K3vGACk0TOfC0ty1/N6VHHq1oIkfJIiABu 2/FdiPAysTrfTA9F1fX6eQ3UiD9rzyo6JB58Ew9E2IFpqHoiz2wiNg7ha8wfIbzfy740 BFTw== X-Gm-Message-State: AJcUukft34DnmzoD81QcHbN6ya/dkmcprCD/oQ9FL+JgnACSJcQo/Zk/ 8yba5uDmIqKveqAg1m7haOCcAA== X-Google-Smtp-Source: ALg8bN5YNeI59k7N2Iy5BkOS+1YeIWH0GaXoli7bgrvb7FNHkclAuxK3xT1hHl+yviz6Jkofmge34Q== X-Received: by 2002:a0d:e901:: with SMTP id s1mr24946614ywe.97.1548790000218; Tue, 29 Jan 2019 11:26:40 -0800 (PST) Received: from rosewood.cam.corp.google.com ([2620:0:1013:11:89c6:2139:5435:371d]) by smtp.gmail.com with ESMTPSA id j134sm18130704ywb.91.2019.01.29.11.26.38 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 29 Jan 2019 11:26:38 -0800 (PST) From: Sean Paul To: dri-devel@lists.freedesktop.org Cc: daniel@ffwll.ch, Sean Paul , =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= , Sam Ravnborg , Maarten Lankhorst , Maxime Ripard , Sean Paul , David Airlie , linux-doc@vger.kernel.org Subject: [PATCH v3] drm/TODO: Add drm_display_mode.hsync/vrefresh removal Date: Tue, 29 Jan 2019 14:26:29 -0500 Message-Id: <20190129192637.73296-1-sean@poorly.run> X-Mailer: git-send-email 2.20.1.495.gaa96b0ce6b-goog In-Reply-To: <20190129172441.GX3271@phenom.ffwll.local> References: <20190129172441.GX3271@phenom.ffwll.local> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org From: Sean Paul Drivers shouldn't be using these values, add a TODO so someone removes them. Changes in v2: - Add drm_display_mode.vrefresh removal (Ville) - Add Sam's R-b and bonus points Changes in v3: - Add hsync removal todo item (Daniel) - Change vrefresh wording to make removal less optional Cc: Ville Syrjälä Suggested-by: Daniel Vetter Reviewed-by: Daniel Vetter Reviewed-by: Sam Ravnborg Bonus-points-awarded-by: Sam Ravnborg Signed-off-by: Sean Paul --- This time with feeling. Documentation/gpu/todo.rst | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst index 38360ede12215..f67c84b92873c 100644 --- a/Documentation/gpu/todo.rst +++ b/Documentation/gpu/todo.rst @@ -262,6 +262,34 @@ As a reference, take a look at the conversions already completed in drm core. Contact: Sean Paul, respective driver maintainers +Convert direct mode.vrefresh accesses to use drm_mode_vrefresh() +---------------------------------------------------------------- + +drm_display_mode.vrefresh isn't guaranteed to be populated. As such, using it +is risky and has been known to cause div-by-zero bugs. Fortunately, drm core +has helper which will use mode.vrefresh if it's !0 and will calculate it from +the timings when it's 0. + +Use simple search/replace, or (more fun) cocci to replace instances of direct +vrefresh access with a call to the helper. Check out +https://lists.freedesktop.org/archives/dri-devel/2019-January/205186.html for +inspiration. + +Once all instances of vrefresh have been converted, remove vrefresh from +drm_display_mode to avoid future use. + +Contact: Sean Paul + +Remove drm_display_mode.hsync +----------------------------- + +We have drm_mode_hsync() to calculate this from hsync_start/end, since drivers +shouldn't/don't use this, remove this member to avoid any temptations to use it +in the future. If there is any debug code using drm_display_mode.hsync, convert +it to use drm_mode_hsync() instead. + +Contact: Sean Paul + Core refactorings ================= -- Sean Paul, Software Engineer, Google / Chromium OS From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sean Paul Subject: [PATCH v3] drm/TODO: Add drm_display_mode.hsync/vrefresh removal Date: Tue, 29 Jan 2019 14:26:29 -0500 Message-ID: <20190129192637.73296-1-sean@poorly.run> References: <20190129172441.GX3271@phenom.ffwll.local> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from mail-yw1-xc43.google.com (mail-yw1-xc43.google.com [IPv6:2607:f8b0:4864:20::c43]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2E3A06E93E for ; Tue, 29 Jan 2019 19:26:42 +0000 (UTC) Received: by mail-yw1-xc43.google.com with SMTP id t13so8627458ywe.13 for ; Tue, 29 Jan 2019 11:26:42 -0800 (PST) In-Reply-To: <20190129172441.GX3271@phenom.ffwll.local> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: dri-devel@lists.freedesktop.org Cc: linux-doc@vger.kernel.org, Maxime Ripard , Sean Paul , David Airlie , Sean Paul , Sam Ravnborg List-Id: dri-devel@lists.freedesktop.org RnJvbTogU2VhbiBQYXVsIDxzZWFucGF1bEBjaHJvbWl1bS5vcmc+CgpEcml2ZXJzIHNob3VsZG4n dCBiZSB1c2luZyB0aGVzZSB2YWx1ZXMsIGFkZCBhIFRPRE8gc28gc29tZW9uZSByZW1vdmVzCnRo ZW0uCgpDaGFuZ2VzIGluIHYyOgotIEFkZCBkcm1fZGlzcGxheV9tb2RlLnZyZWZyZXNoIHJlbW92 YWwgKFZpbGxlKQotIEFkZCBTYW0ncyBSLWIgYW5kIGJvbnVzIHBvaW50cwpDaGFuZ2VzIGluIHYz OgotIEFkZCBoc3luYyByZW1vdmFsIHRvZG8gaXRlbSAoRGFuaWVsKQotIENoYW5nZSB2cmVmcmVz aCB3b3JkaW5nIHRvIG1ha2UgcmVtb3ZhbCBsZXNzIG9wdGlvbmFsCgpDYzogVmlsbGUgU3lyasOk bMOkIDx2aWxsZS5zeXJqYWxhQGxpbnV4LmludGVsLmNvbT4KU3VnZ2VzdGVkLWJ5OiBEYW5pZWwg VmV0dGVyIDxkYW5pZWxAZmZ3bGwuY2g+ClJldmlld2VkLWJ5OiBEYW5pZWwgVmV0dGVyIDxkYW5p ZWxAZmZ3bGwuY2g+ClJldmlld2VkLWJ5OiBTYW0gUmF2bmJvcmcgPHNhbUByYXZuYm9yZy5vcmc+ CkJvbnVzLXBvaW50cy1hd2FyZGVkLWJ5OiBTYW0gUmF2bmJvcmcgPHNhbUByYXZuYm9yZy5vcmc+ ClNpZ25lZC1vZmYtYnk6IFNlYW4gUGF1bCA8c2VhbnBhdWxAY2hyb21pdW0ub3JnPgotLS0KClRo aXMgdGltZSB3aXRoIGZlZWxpbmcuCgogRG9jdW1lbnRhdGlvbi9ncHUvdG9kby5yc3QgfCAyOCAr KysrKysrKysrKysrKysrKysrKysrKysrKysrCiAxIGZpbGUgY2hhbmdlZCwgMjggaW5zZXJ0aW9u cygrKQoKZGlmZiAtLWdpdCBhL0RvY3VtZW50YXRpb24vZ3B1L3RvZG8ucnN0IGIvRG9jdW1lbnRh dGlvbi9ncHUvdG9kby5yc3QKaW5kZXggMzgzNjBlZGUxMjIxNS4uZjY3Yzg0YjkyODczYyAxMDA2 NDQKLS0tIGEvRG9jdW1lbnRhdGlvbi9ncHUvdG9kby5yc3QKKysrIGIvRG9jdW1lbnRhdGlvbi9n cHUvdG9kby5yc3QKQEAgLTI2Miw2ICsyNjIsMzQgQEAgQXMgYSByZWZlcmVuY2UsIHRha2UgYSBs b29rIGF0IHRoZSBjb252ZXJzaW9ucyBhbHJlYWR5IGNvbXBsZXRlZCBpbiBkcm0gY29yZS4KIAog Q29udGFjdDogU2VhbiBQYXVsLCByZXNwZWN0aXZlIGRyaXZlciBtYWludGFpbmVycwogCitDb252 ZXJ0IGRpcmVjdCBtb2RlLnZyZWZyZXNoIGFjY2Vzc2VzIHRvIHVzZSBkcm1fbW9kZV92cmVmcmVz aCgpCistLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0t LS0tLS0tLS0tLS0tCisKK2RybV9kaXNwbGF5X21vZGUudnJlZnJlc2ggaXNuJ3QgZ3VhcmFudGVl ZCB0byBiZSBwb3B1bGF0ZWQuIEFzIHN1Y2gsIHVzaW5nIGl0CitpcyByaXNreSBhbmQgaGFzIGJl ZW4ga25vd24gdG8gY2F1c2UgZGl2LWJ5LXplcm8gYnVncy4gRm9ydHVuYXRlbHksIGRybSBjb3Jl CitoYXMgaGVscGVyIHdoaWNoIHdpbGwgdXNlIG1vZGUudnJlZnJlc2ggaWYgaXQncyAhMCBhbmQg d2lsbCBjYWxjdWxhdGUgaXQgZnJvbQordGhlIHRpbWluZ3Mgd2hlbiBpdCdzIDAuCisKK1VzZSBz aW1wbGUgc2VhcmNoL3JlcGxhY2UsIG9yIChtb3JlIGZ1bikgY29jY2kgdG8gcmVwbGFjZSBpbnN0 YW5jZXMgb2YgZGlyZWN0Cit2cmVmcmVzaCBhY2Nlc3Mgd2l0aCBhIGNhbGwgdG8gdGhlIGhlbHBl ci4gQ2hlY2sgb3V0CitodHRwczovL2xpc3RzLmZyZWVkZXNrdG9wLm9yZy9hcmNoaXZlcy9kcmkt ZGV2ZWwvMjAxOS1KYW51YXJ5LzIwNTE4Ni5odG1sIGZvcgoraW5zcGlyYXRpb24uCisKK09uY2Ug YWxsIGluc3RhbmNlcyBvZiB2cmVmcmVzaCBoYXZlIGJlZW4gY29udmVydGVkLCByZW1vdmUgdnJl ZnJlc2ggZnJvbQorZHJtX2Rpc3BsYXlfbW9kZSB0byBhdm9pZCBmdXR1cmUgdXNlLgorCitDb250 YWN0OiBTZWFuIFBhdWwKKworUmVtb3ZlIGRybV9kaXNwbGF5X21vZGUuaHN5bmMKKy0tLS0tLS0t LS0tLS0tLS0tLS0tLS0tLS0tLS0tCisKK1dlIGhhdmUgZHJtX21vZGVfaHN5bmMoKSB0byBjYWxj dWxhdGUgdGhpcyBmcm9tIGhzeW5jX3N0YXJ0L2VuZCwgc2luY2UgZHJpdmVycworc2hvdWxkbid0 L2Rvbid0IHVzZSB0aGlzLCByZW1vdmUgdGhpcyBtZW1iZXIgdG8gYXZvaWQgYW55IHRlbXB0YXRp b25zIHRvIHVzZSBpdAoraW4gdGhlIGZ1dHVyZS4gSWYgdGhlcmUgaXMgYW55IGRlYnVnIGNvZGUg dXNpbmcgZHJtX2Rpc3BsYXlfbW9kZS5oc3luYywgY29udmVydAoraXQgdG8gdXNlIGRybV9tb2Rl X2hzeW5jKCkgaW5zdGVhZC4KKworQ29udGFjdDogU2VhbiBQYXVsCisKIENvcmUgcmVmYWN0b3Jp bmdzCiA9PT09PT09PT09PT09PT09PQogCi0tIApTZWFuIFBhdWwsIFNvZnR3YXJlIEVuZ2luZWVy LCBHb29nbGUgLyBDaHJvbWl1bSBPUwoKX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX18KZHJpLWRldmVsIG1haWxpbmcgbGlzdApkcmktZGV2ZWxAbGlzdHMuZnJl ZWRlc2t0b3Aub3JnCmh0dHBzOi8vbGlzdHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGlu Zm8vZHJpLWRldmVsCg==