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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 11122C4345F for ; Fri, 19 Apr 2024 04:38:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:MIME-Version: Message-ID:In-Reply-To:Date:References:Subject:Cc:To:From:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=ej7/fw9lYlLjAatAPHpa1xvllku8tukbdTdeuDUgBTI=; b=TU8Jlx2i/tHsw8fqb5215Iiizf jkYpPyZcDWXTtj2njRh8djIyndYZpXKCFlW6MxyLRffn1Tyh+QEi5Vv3Skr1HpTVylGtjVSFxAygi anf/LUkQZIJAaF5LZM/QBFIXKqwmXizx5eATTiYtRiYrg8l5vsMl35Ls6da3TTd+Z7eQceOGs+0vT Y0oqI+5/s6Vc/k//2aVqoYoTpV+nk3cezgZeShX5RyWCCjsXvFZnTsM+aNzMVlIo+V5ZMAJihbTcB M6K2aZw77ArWdMwC/PyRS/ueSqvrTD8vMbHTMf02XMi+MK0+ARKcUCeRvyY/23I8nQXEUZlMFicuN bdCug55A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rxg11-00000004N2o-2mg8 for ath12k@archiver.kernel.org; Fri, 19 Apr 2024 04:38:23 +0000 Received: from sin.source.kernel.org ([2604:1380:40e1:4800::1]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rxg0x-00000004N2M-1r16 for ath12k@lists.infradead.org; Fri, 19 Apr 2024 04:38:21 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sin.source.kernel.org (Postfix) with ESMTP id B718DCE19D0; Fri, 19 Apr 2024 04:38:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 08906C072AA; Fri, 19 Apr 2024 04:38:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1713501495; bh=oN18J2DU6Hqp6cJkmQ5aDnAYJ+tq1Th27S8Iarum1kA=; h=From:To:Cc:Subject:References:Date:In-Reply-To:From; b=a69O2TQyXevQmUquepZSH/u/broFRWFUXWSPKGRYQIFAzI4bEAQtCuQUvJr58t/29 kZ8irE2R0HXXpgfnJ6fgZDj3cIwWv6mNWo4ldZ4cypLFNZzcwVsWumV7mFerNzmSld LIyYujirby5TVs45dwiHe6A9zonWX5tFP21Ue08g32AleLYy6YkLSZ4TplCAk+4C8s gIc3ty6dva4pjHh9naVG///Mrtcnsew/icNCeaFBjV96gpKt4x5+8HJHUra9iRmJOT pB+tpWreY2ybhaz4zEwUEq5jUHaIXVKRXPLTTj6IC5Seh0w8mSgzFlXvxBrdGa0/mb SnY3WT4PsWPLg== From: Kalle Valo To: Baochen Qiang Cc: , Subject: Re: [PATCH] wifi: ath12k: fix kernel crash during resume References: <20240419034034.2842-1-quic_bqiang@quicinc.com> <87cyqmhtoi.fsf@kernel.org> Date: Fri, 19 Apr 2024 07:38:11 +0300 In-Reply-To: <87cyqmhtoi.fsf@kernel.org> (Kalle Valo's message of "Fri, 19 Apr 2024 07:18:05 +0300") Message-ID: <87frvivufg.fsf@kernel.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240418_213819_872450_9EC712D2 X-CRM114-Status: GOOD ( 19.28 ) X-BeenThere: ath12k@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "ath12k" Errors-To: ath12k-bounces+ath12k=archiver.kernel.org@lists.infradead.org Kalle Valo writes: > Baochen Qiang writes: > >> Currently during resume, QMI target memory is not properly handled, resulting >> in kernel crash in case DMA remap is not supported: >> >> BUG: Bad page state in process kworker/u16:54 pfn:36e80 >> page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x36e80 >> page dumped because: nonzero _refcount >> Call Trace: >> bad_page >> free_page_is_bad_report >> __free_pages_ok >> __free_pages >> dma_direct_free >> dma_free_attrs >> ath12k_qmi_free_target_mem_chunk >> ath12k_qmi_msg_mem_request_cb >> >> The reason is: >> Once ath12k module is loaded, firmware sends memory request to host. In case >> DMA remap not supported, ath12k refuses the first request due to failure in >> allocating with large segment size: >> >> ath12k_pci 0000:04:00.0: qmi firmware request memory request >> ath12k_pci 0000:04:00.0: qmi mem seg type 1 size 7077888 >> ath12k_pci 0000:04:00.0: qmi mem seg type 4 size 8454144 >> ath12k_pci 0000:04:00.0: qmi dma allocation failed (7077888 B type 1), will try later with small size >> ath12k_pci 0000:04:00.0: qmi delays mem_request 2 >> ath12k_pci 0000:04:00.0: qmi firmware request memory request >> >> Later firmware comes back with more but small segments and allocation >> succeeds: >> >> ath12k_pci 0000:04:00.0: qmi mem seg type 1 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 1 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 1 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 1 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 1 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 1 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 1 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 1 size 262144 >> ath12k_pci 0000:04:00.0: qmi mem seg type 1 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 1 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 1 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 1 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 1 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 4 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 4 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 4 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 4 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 4 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 4 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 4 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 4 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 4 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 4 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 4 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 4 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 4 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 4 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 4 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 4 size 524288 >> ath12k_pci 0000:04:00.0: qmi mem seg type 4 size 65536 >> ath12k_pci 0000:04:00.0: qmi mem seg type 1 size 524288 >> >> Now ath12k is working. If suspend is triggered, firmware will be reloaded >> during resume. As same as before, firmware requests two large segments at >> first. In ath12k_qmi_msg_mem_request_cb() segment count and size are >> assigned: >> >> ab->qmi.mem_seg_count == 2 >> ab->qmi.target_mem[0].size == 7077888 >> ab->qmi.target_mem[1].size == 8454144 >> >> Then allocation failed like before and ath12k_qmi_free_target_mem_chunk() >> is called to free all allocated segments. Note the first segment is skipped >> because its v.addr is cleared due to allocation failure: >> >> chunk->v.addr = dma_alloc_coherent() >> >> Also note that this leaks that segment because it has not been freed. >> >> While freeing the second segment, a size of 8454144 is passed to >> dma_free_coherent(). However remember that this segment is allocated at >> the first time firmware is loaded, before suspend. So its real size is >> 524288, much smaller than 8454144. As a result kernel found we are freeing >> some memory which is in use and thus crashed. >> >> So one possible fix would be to free those segments during suspend. This >> works because with them freed, ath12k_qmi_free_target_mem_chunk() does >> nothing: all segment addresses are NULL so dma_free_coherent() is not called. >> >> But note that ath11k has similar logic but never hits this issue. Reviewing >> code there shows the luck comes from QMI memory reuse logic. So the decision >> is to port it to ath12k. Like in ath11k, the crash is avoided by adding >> prev_size to target_mem_chunk structure and caching real segment size in it, >> then prev_size instead of current size is passed to dma_free_coherent(), >> no unexpected memory is freed now. >> >> Also reuse m3 buffer. >> >> Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0-03427-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.15378.4 >> Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3 >> >> Fixes: 64430ddfb132 ("wifi: ath12k: support suspend/resume") ERROR: Commit id not found from current branch: Fixes: 64430ddfb132 ("wifi: ath12k: support suspend/resume") Do note that commit ids in the pending branch are not stable so fixes tags cannot be used for those commits. >> Signed-off-by: Baochen Qiang > > To keep git bisect clean should this patch be applied before applying > the suspend patchset? No need resend or anything, just checking what > should be the correct order. Ah, I just checked and it looks like this patch depends on the suspend patchset. I now applied this patch to pendign branch (ath-pending-202404190433). -- https://patchwork.kernel.org/project/linux-wireless/list/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches