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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0482AC433FE for ; Fri, 11 Nov 2022 11:15:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233429AbiKKLP2 (ORCPT ); Fri, 11 Nov 2022 06:15:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35112 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230377AbiKKLP0 (ORCPT ); Fri, 11 Nov 2022 06:15:26 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5282E6711D for ; Fri, 11 Nov 2022 03:15:25 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id CC551B825C4 for ; Fri, 11 Nov 2022 11:15:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 23C66C433C1; Fri, 11 Nov 2022 11:15:17 +0000 (UTC) Date: Fri, 11 Nov 2022 11:15:11 +0000 From: Catalin Marinas To: Amit Pundir Cc: Robin Murphy , Bjorn Andersson , Sibi Sankar , Manivannan Sadhasivam , Will Deacon , Linus Torvalds , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Dmitry Baryshkov Subject: Re: [GIT PULL] arm64 updates for 6.1-rc1 Message-ID: References: <20221005144116.2256580-1-catalin.marinas@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 08, 2022 at 10:58:16PM +0530, Amit Pundir wrote: > On Tue, 25 Oct 2022 at 18:08, Amit Pundir wrote: > > On Wed, 12 Oct 2022 at 17:24, Catalin Marinas wrote: > > > On Sat, Oct 08, 2022 at 08:28:26PM +0530, Amit Pundir wrote: > > > > On Wed, 5 Oct 2022 at 20:11, Catalin Marinas wrote: > > > > > Will Deacon (2): > > > > > arm64: dma: Drop cache invalidation from arch_dma_prep_coherent() > > > > > > > > This patch broke AOSP on Dragonboard 845c (SDM845). I don't see any > > > > relevant crash in the attached log and device silently reboots into > > > > USB crash dump mode. The crash is fairly reproducible on db845c. I > > > > could trigger it twice in 5 reboots and it always crash at the same > > > > point during the boot process. Reverting this patch fixes the crash. > > > > > > > > I'm happy to test run any debug patche(s), that would help narrow > > > > down this breakage. [...] > > Further narrowed down the breakage to the userspace daemon rmtfs > > https://github.com/andersson/rmtfs. Is there anything specific in the > > userspace code that I should be paying attention to? Since you don't see anything in the logs like a crash and the system restarts, I suspect it's some deadlock and that's triggering the watchdog. We have an erratum (826319) but that's for Cortex-A53. IIUC SDM845 has Kryo 3xx series which based on some random google searches is derived from A75/A55. Unfortunately the MIDR_EL1 register doesn't match the Arm Ltd numbering, so I have no idea what CPUs these are by looking at the boot log. I wouldn't be surprised if you hit a similar bug, though I couldn't find anything close in the A55 errata notice. While we could revert commit c44094eee32f ("arm64: dma: Drop cache invalidation from arch_dma_prep_coherent()"), if you hit a real hardware issue it may trigger in other scenario where we only do cache cleaning (without invalidate), like arch_sync_dma_for_device(). So I'd rather get to the bottom of this and potentially enable the workaround for this chipset. You could give it a quick try to by adding the MIDR ranges for SDM845 to struct midr_range workaround_clean_cache[]. After that I suggest you raise it with Qualcomm to investigate. Normally we ask for an erratum number to enable a workaround and it's only Qualcomm that can provide one here. -- Catalin