From patchwork Mon Nov 14 19:19:02 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: hotran X-Patchwork-Id: 9428281 X-Patchwork-Delegate: rjw@sisk.pl Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 6C0F860755 for ; Mon, 14 Nov 2016 19:20:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5FD6E28655 for ; Mon, 14 Nov 2016 19:20:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 541CD28921; Mon, 14 Nov 2016 19:20:31 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.3 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI, RCVD_IN_SORBS_SPAM, T_DKIM_INVALID autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DCE552865D for ; Mon, 14 Nov 2016 19:20:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936474AbcKNTU0 (ORCPT ); Mon, 14 Nov 2016 14:20:26 -0500 Received: from mail-it0-f48.google.com ([209.85.214.48]:37387 "EHLO mail-it0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935646AbcKNTUY (ORCPT ); Mon, 14 Nov 2016 14:20:24 -0500 Received: by mail-it0-f48.google.com with SMTP id b123so45800073itb.0 for ; Mon, 14 Nov 2016 11:20:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=apm.com; s=apm; h=from:to:cc:subject:date:message-id; bh=veSctgH3s94VnmTF2YY41pCyK1F4n4fDd/N3LBOdLtQ=; b=alalnDABgRc1JUspiMrwVGZRIK0tB/9wkqy9iTfOwKw0wOfOypQ4Xj1DrzZ/vJrlJc Zel/Cwh8SMJ7CXXDb/IdD3r5YK12TtqU1+8e4STm/tvPE6FD1Wcyk2PpIjjGW/xP/D1i riijNwtz5KEwXtUrszLTNxbyHmiZphT8v8Z3Y= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=veSctgH3s94VnmTF2YY41pCyK1F4n4fDd/N3LBOdLtQ=; b=deIN4Z/Qlqgr8Wo6XQhDlalxPSQHxdIgMFGvbSkcKmjXSTplwLAFq1PKXzQX3UcFFE 83cDO2NOuKtJWaywVCDV739B/pUFvlkwhLsPg6J9cz4+4NtE7DV82lSAajTAtfFLVHOj ggvWnf1FK2wpouB831TOyTOjcq5iadewJG2G4MAlxs2qfu014YKVyzlGnBZym3qB0sX0 dUrFpOuXz/GfT9ctAlxyBOGQroWuingW25SrU+jtfEJhaUmOSNyGFGqioqauLBh0ojqg ziILtrj8syaQdJbes68a8riQxxxvl9yNmZm/iuc81wOm0wjtgf+rxs9yZP3boTSb1eRr CRLA== X-Gm-Message-State: ABUngvcPabI5U+qBAQLFxgvXVkZBfkl7nkX3iJnXWF1AK2XwPPFQdKPCDtN+8/VhJH4qeFLn X-Received: by 10.107.181.19 with SMTP id e19mr5360685iof.104.1479151220599; Mon, 14 Nov 2016 11:20:20 -0800 (PST) Received: from hotran_localhost.amcc.com ([206.80.4.98]) by smtp.gmail.com with ESMTPSA id l62sm9854676itc.12.2016.11.14.11.20.19 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 14 Nov 2016 11:20:20 -0800 (PST) From: Hoan Tran To: "Rafael J. Wysocki" , Jassi Brar , Prakash Prashanth Cc: linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, lho@apm.com, Duc Dang , Hoan Tran Subject: [PATCH v4] mailbox: PCC: Fix lockdep warning when request PCC channel Date: Mon, 14 Nov 2016 11:19:02 -0800 Message-Id: <1479151142-1876-1-git-send-email-hotran@apm.com> X-Mailer: git-send-email 1.9.1 Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch fixes the lockdep warning below [ 7.229767] DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags)) [ 7.229776] ------------[ cut here ]------------ [ 7.229787] WARNING: CPU: 1 PID: 1 at linux-next/kernel/locking/lockdep.c:2876 loc kdep_trace_alloc+0xe0/0xf0 [ 7.229790] Modules linked in: [ 7.229793] [ 7.229798] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.8.0-11756-g86c5152 #46 ... [ 7.229900] Call trace: [ 7.229903] Exception stack(0xffff8007da837890 to 0xffff8007da8379c0) [ 7.229906] 7880: ffff8007da834000 0001000000000000 [ 7.229909] 78a0: ffff8007da837a70 ffff0000081111a0 00000000600000c5 000000000000003d [ 7.229912] 78c0: 9374bc6a7f3c7832 0000000000381878 ffff000009db7ab8 000000000000002f [ 7.229915] 78e0: ffff00000811aabc ffff000008be2548 ffff8007da837990 ffff00000811adf8 [ 7.229918] 7900: ffff8007da834000 00000000024080c0 00000000000000c0 ffff000009021000 [ 7.229921] 7920: 0000000000000000 0000000000000000 ffff000008c8f7c8 ffff8007da579810 [ 7.229923] 7940: 000000000000002f ffff8007da858000 0000000000000000 0000000000000001 [ 7.229926] 7960: 0000000000000001 0000000000000000 ffff00000811a468 0000000000000002 [ 7.229929] 7980: 656c62617369645f 0000000000038187 00000000000000ee ffff8007da837850 [ 7.229932] 79a0: ffff000009db50c0 ffff000009db569d 0000000000000006 ffff000089db568f [ 7.229936] [] lockdep_trace_alloc+0xe0/0xf0 [ 7.229940] [] __kmalloc_track_caller+0x50/0x250 [ 7.229945] [] devres_alloc_node+0x28/0x60 [ 7.229949] [] devm_request_threaded_irq+0x50/0xe0 [ 7.229955] [] pcc_mbox_request_channel+0x110/0x170 [ 7.229960] [] acpi_cppc_processor_probe+0x264/0x414 [ 7.229963] [] __acpi_processor_start+0x28/0xa0 [ 7.229966] [] acpi_processor_start+0x44/0x54 [ 7.229970] [] driver_probe_device+0x1fc/0x2b0 [ 7.229974] [] __driver_attach+0xb4/0xc0 [ 7.229977] [] bus_for_each_dev+0x5c/0xa0 [ 7.229980] [] driver_attach+0x20/0x30 [ 7.229983] [] bus_add_driver+0x110/0x230 [ 7.229987] [] driver_register+0x60/0x100 [ 7.229991] [] acpi_processor_driver_init+0x2c/0xb0 [ 7.229996] [] do_one_initcall+0x38/0x130 [ 7.230000] [] kernel_init_freeable+0x210/0x2b4 [ 7.230004] [] kernel_init+0x10/0x110 [ 7.230007] [] ret_from_fork+0x10/0x50 It's because the spinlock inside pcc_mbox_request_channel() is kept too long. This patch releases spinlock before request_irq() and free_irq() to fix this issue as spinlock is only needed to protect the channel data. Signed-off-by: Hoan Tran Reviewed-by: Prashanth Prakash --- v4 * Include acpi/pcc.h v3 * Free mailbox irq before reset the channel data * Free channel if it fails to request the mailbox irq v2 * Release spinlock before request_irq() and free_irq() instead of using mutex drivers/mailbox/pcc.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c index 08c87fa..1f32688 100644 --- a/drivers/mailbox/pcc.c +++ b/drivers/mailbox/pcc.c @@ -65,6 +65,7 @@ #include #include #include +#include #include "mailbox.h" @@ -267,6 +268,8 @@ struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl, if (chan->txdone_method == TXDONE_BY_POLL && cl->knows_txdone) chan->txdone_method |= TXDONE_BY_ACK; + spin_unlock_irqrestore(&chan->lock, flags); + if (pcc_doorbell_irq[subspace_id] > 0) { int rc; @@ -275,12 +278,11 @@ struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl, if (unlikely(rc)) { dev_err(dev, "failed to register PCC interrupt %d\n", pcc_doorbell_irq[subspace_id]); + pcc_mbox_free_channel(chan); chan = ERR_PTR(rc); } } - spin_unlock_irqrestore(&chan->lock, flags); - return chan; } EXPORT_SYMBOL_GPL(pcc_mbox_request_channel); @@ -304,20 +306,19 @@ void pcc_mbox_free_channel(struct mbox_chan *chan) return; } + if (pcc_doorbell_irq[id] > 0) + devm_free_irq(chan->mbox->dev, pcc_doorbell_irq[id], chan); + spin_lock_irqsave(&chan->lock, flags); chan->cl = NULL; chan->active_req = NULL; if (chan->txdone_method == (TXDONE_BY_POLL | TXDONE_BY_ACK)) chan->txdone_method = TXDONE_BY_POLL; - if (pcc_doorbell_irq[id] > 0) - devm_free_irq(chan->mbox->dev, pcc_doorbell_irq[id], chan); - spin_unlock_irqrestore(&chan->lock, flags); } EXPORT_SYMBOL_GPL(pcc_mbox_free_channel); - /** * pcc_send_data - Called from Mailbox Controller code. Used * here only to ring the channel doorbell. The PCC client