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=-13.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 65D44C433ED for ; Wed, 19 May 2021 17:54:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3EA6F61244 for ; Wed, 19 May 2021 17:54:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230144AbhESRzh (ORCPT ); Wed, 19 May 2021 13:55:37 -0400 Received: from mga14.intel.com ([192.55.52.115]:52440 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229638AbhESRzg (ORCPT ); Wed, 19 May 2021 13:55:36 -0400 IronPort-SDR: YHmgIaFQtMdhJFSS/BLTg2JouLiR9hC88I970bq80x9rnnUvy7hsrktbyqV/rTXNIQmRvP3CMR aaNnkn7LIXiQ== X-IronPort-AV: E=McAfee;i="6200,9189,9989"; a="200733950" X-IronPort-AV: E=Sophos;i="5.82,313,1613462400"; d="scan'208";a="200733950" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 May 2021 10:54:16 -0700 IronPort-SDR: LlNtnbY8vGiLibUePftAI8Se9VVkvfMgNfB2LU2rvYLFQ+ZIrt7DmbA+AdMa8CW2L1VNgeqxW3 wZi67gbqXdDQ== X-IronPort-AV: E=Sophos;i="5.82,313,1613462400"; d="scan'208";a="473602252" Received: from akrolak-mobl.ger.corp.intel.com (HELO localhost) ([10.249.37.74]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 May 2021 10:54:12 -0700 From: Jani Nikula To: Sergei Trofimovich , Christoph Hellwig Cc: Chris Wilson , Daniel Vetter , Joonas Lahtinen , Peter Zijlstra , Rodrigo Vivi , linux-kernel@vger.kernel.org Subject: Re: [bisected] 5.13-rc2 i915 regression in b12d691ea5e01d "i915: fix remap_io_sg to verify the pgprot" In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: Date: Wed, 19 May 2021 20:54:09 +0300 Message-ID: <87fsyiehj2.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 19 May 2021, Sergei Trofimovich wrote: > Hi Christoph and i915 maintainers! > > vanilla 5.13-rc2 got some rendering regression on gen2(?) i915 chips: 293837b9ac8d ("Revert "i915: fix remap_io_sg to verify the pgprot"") will be included in v5.13-rc3. BR, Jani. > > In gtk apps cursor gets corrupted for a short period of time. > > In firefox text selection and text scrolling shows artifacts for a short > time (seconds). As if tiny horisontal tiles (1 pixel high, ~20-50 pixels > long) fail to refresh in time. > > I was not able get a screenshot with artifacts: pictures are always clean. > I can grab a photo or tiny video if needed. > > Bisection was straightforward and landed on: > > b12d691ea5e01db42ccf3b4207e57cb3ce7cfe91 is the first bad commit > commit b12d691ea5e01db42ccf3b4207e57cb3ce7cfe91 > Author: Christoph Hellwig > Date: Thu Apr 29 22:57:38 2021 -0700 > > i915: fix remap_io_sg to verify the pgprot > > remap_io_sg claims that the pgprot is pre-verified using an io_mapping, > but actually does not get passed an io_mapping and just uses the pgprot in > the VMA. Remove the apply_to_page_range abuse and just loop over > remap_pfn_range for each segment. > > Note: this could use io_mapping_map_user by passing an iomap to > remap_io_sg if the maintainers can verify that the pgprot in the iomap in > the only caller is indeed the desired one here. > > Link: https://lkml.kernel.org/r/20210326055505.1424432-5-hch@lst.de > Signed-off-by: Christoph Hellwig > Cc: Chris Wilson > Cc: Daniel Vetter > Cc: Jani Nikula > Cc: Joonas Lahtinen > Cc: Peter Zijlstra > Cc: Rodrigo Vivi > Signed-off-by: Andrew Morton > Signed-off-by: Linus Torvalds > > drivers/gpu/drm/i915/i915_mm.c | 73 +++++++++++++----------------------------- > 1 file changed, 23 insertions(+), 50 deletions(-) > > System: > $ Linux sf 5.12.0-11146-g8ca5297e7e38 #302 SMP PREEMPT Thu Apr 29 23:30:52 BST 2021 x86_64 Intel(R) Core(TM) i7-2700K CPU @ 3.50GHz GenuineIntel GNU/Linux > $ lspci -v > 00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09) (prog-if 00 [VGA controller]) > Subsystem: Gigabyte Technology Co., Ltd 2nd Generation Core Processor Family Integrated Graphics Controller > Flags: bus master, fast devsel, latency 0, IRQ 27 > Memory at f7800000 (64-bit, non-prefetchable) [size=4M] > Memory at e0000000 (64-bit, prefetchable) [size=256M] > I/O ports at f000 [size=64] > Expansion ROM at 000c0000 [virtual] [disabled] [size=128K] > Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit- > Capabilities: [d0] Power Management version 2 > Capabilities: [a4] PCI Advanced Features > Kernel driver in use: i915 > > Software: > mesa-20.3.5 : i965 driver > glamor X acceleration enabled on Mesa DRI Intel(R) HD Graphics 3000 (SNB GT2) > xorg-server-1.20.11 > > Thanks! -- Jani Nikula, Intel Open Source Graphics Center