From patchwork Thu Oct 27 22:34:44 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: hotran X-Patchwork-Id: 9400619 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 95D3960588 for ; Thu, 27 Oct 2016 22:36:14 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7BDC32A1B7 for ; Thu, 27 Oct 2016 22:36:14 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 70B402A1EA; Thu, 27 Oct 2016 22:36:14 +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 C3C3B2A1B7 for ; Thu, 27 Oct 2016 22:36:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S942825AbcJ0WgM (ORCPT ); Thu, 27 Oct 2016 18:36:12 -0400 Received: from mail-pf0-f171.google.com ([209.85.192.171]:34677 "EHLO mail-pf0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S942790AbcJ0Wfm (ORCPT ); Thu, 27 Oct 2016 18:35:42 -0400 Received: by mail-pf0-f171.google.com with SMTP id n85so25107445pfi.1 for ; Thu, 27 Oct 2016 15:35:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=apm.com; s=apm; h=from:to:cc:subject:date:message-id; bh=XtzMS213OcXUiAnw3Q/6z3Ql2ACWjvkkvIM2wvIGknM=; b=gzIoxnZMkoHOculCfZxjf+ufb3sczkpkTJlHy41jdQVi8XpOmcHd2i+Hz481mmnWeG dvZ39bjVRAcJykMUuBxMWUa6fPAZYC3PkCCB5AMb4LLEnDQ7ECZtgOqarclM3mBx4b5J m3HX7CCCapY6vsO91NuwlCf8+VOeLLmYKhSUA= 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=XtzMS213OcXUiAnw3Q/6z3Ql2ACWjvkkvIM2wvIGknM=; b=Ww0OIDe8lYBgp9Pxz9753rDykhaS1AEzNTq3B9pZSuBrm4Jcy9P1xyL+V+xpyZK1jC +lGah3xie0gCQYrprSsJEuuV1syvOp/kqEr9bpx8n5DkBhRJ+DGKJxJno+ZOeAIbQv3d b8SS+aGHC2PLNG9BI6ImdZbZlRuU0Z2PcGO5c71H6q0R+16x2+mjPyJIu3AnKuGD1YHs LIAPH6UDkw/vHvSAj8g/o5gmdpZZDaX3ieOV2ieixHjIPd2uouI/FwLNS1CwGxyyX1TI DFqX1Z0JIOFWi4l9pvaphPaqzol4Dt9cWoz2WNPs2bpCu4rOH+U8AUYaaEjedL6SOPR7 ITPg== X-Gm-Message-State: ABUngvddagQHhFc+PTNIJRZ+ruziCu+4g8rjCKOw8Pjle3qsmLccTBlaEpwi53XmsaA5hBNk X-Received: by 10.98.10.6 with SMTP id s6mr18783041pfi.8.1477607741579; Thu, 27 Oct 2016 15:35:41 -0700 (PDT) Received: from hotran_localhost.amcc.com ([206.80.4.98]) by smtp.gmail.com with ESMTPSA id w67sm14016435pfd.36.2016.10.27.15.35.40 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 27 Oct 2016 15:35:41 -0700 (PDT) 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 v3] mailbox: PCC: Fix lockdep warning when request PCC channel Date: Thu, 27 Oct 2016 15:34:44 -0700 Message-Id: <1477607684-5314-1-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 --- 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 | 70 +++++++++++++++++++++++++-------------------------- 1 file changed, 35 insertions(+), 35 deletions(-) diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c index 08c87fa..4b2f061 100644 --- a/drivers/mailbox/pcc.c +++ b/drivers/mailbox/pcc.c @@ -224,6 +224,38 @@ static irqreturn_t pcc_mbox_irq(int irq, void *p) } /** + * pcc_mbox_free_channel - Clients call this to free their Channel. + * + * @chan: Pointer to the mailbox channel as returned by + * pcc_mbox_request_channel() + */ +void pcc_mbox_free_channel(struct mbox_chan *chan) +{ + u32 id = chan - pcc_mbox_channels; + unsigned long flags; + + if (!chan || !chan->cl) + return; + + if (id >= pcc_mbox_ctrl.num_chans) { + pr_debug("pcc_mbox_free_channel: Invalid mbox_chan passed\n"); + 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; + + spin_unlock_irqrestore(&chan->lock, flags); +} +EXPORT_SYMBOL_GPL(pcc_mbox_free_channel); + +/** * pcc_mbox_request_channel - PCC clients call this function to * request a pointer to their PCC subspace, from which they * can get the details of communicating with the remote. @@ -267,6 +299,8 @@ 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; @@ -275,50 +309,16 @@ 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); /** - * pcc_mbox_free_channel - Clients call this to free their Channel. - * - * @chan: Pointer to the mailbox channel as returned by - * pcc_mbox_request_channel() - */ -void pcc_mbox_free_channel(struct mbox_chan *chan) -{ - u32 id = chan - pcc_mbox_channels; - unsigned long flags; - - if (!chan || !chan->cl) - return; - - if (id >= pcc_mbox_ctrl.num_chans) { - pr_debug("pcc_mbox_free_channel: Invalid mbox_chan passed\n"); - return; - } - - 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 * specific read/write is done in the client driver in