Return-path: Received: from mx0a-0016f401.pphosted.com ([67.231.148.174]:53916 "EHLO mx0b-0016f401.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S935962AbcJTN1A (ORCPT ); Thu, 20 Oct 2016 09:27:00 -0400 From: Amitkumar Karwar To: CC: Cathy Luo , Nishant Sarmukadam , , , Xinming Hu , Amitkumar Karwar Subject: [PATCH v5 4/4] mwifiex: fix race for card->adapter Date: Thu, 20 Oct 2016 18:56:19 +0530 Message-ID: <1476969979-28554-4-git-send-email-akarwar@marvell.com> (sfid-20161020_152703_422772_D0A70F48) In-Reply-To: <1476969979-28554-1-git-send-email-akarwar@marvell.com> References: <1476969979-28554-1-git-send-email-akarwar@marvell.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-wireless-owner@vger.kernel.org List-ID: From: Xinming Hu card->adapter is set/reset in register/unregister calls. Firmware gets downloaded asynchronously in a separate thread during init. We have a unregister call when firmware initialization fails. It may have a race with suspend thread where "card->adapter" is being read. This patch adds spinlock to fix the problem. Signed-off-by: Cathy Luo Signed-off-by: Xinming Hu Signed-off-by: Amitkumar Karwar --- New patch introduced in v5 to address race between driver init and suspend threads. --- drivers/net/wireless/marvell/mwifiex/pcie.c | 38 +++++++++++++++++++++++------ drivers/net/wireless/marvell/mwifiex/pcie.h | 2 ++ 2 files changed, 32 insertions(+), 8 deletions(-) diff --git a/drivers/net/wireless/marvell/mwifiex/pcie.c b/drivers/net/wireless/marvell/mwifiex/pcie.c index 94f75be..9147e6a 100644 --- a/drivers/net/wireless/marvell/mwifiex/pcie.c +++ b/drivers/net/wireless/marvell/mwifiex/pcie.c @@ -102,23 +102,32 @@ static int mwifiex_pcie_suspend(struct device *dev) struct mwifiex_adapter *adapter; struct pcie_service_card *card; struct pci_dev *pdev = to_pci_dev(dev); + unsigned long flags; card = pci_get_drvdata(pdev); - if (!card || !card->adapter || - card->adapter->hw_status == MWIFIEX_HW_STATUS_RESET || - card->adapter->hw_status == MWIFIEX_HW_STATUS_NOT_READY) { - pr_err("Card or adapter structure is not valid or hw_status shows failure\n"); + if (!card) { + pr_err("Card is not valid\n"); return 0; } + spin_lock_irqsave(&card->adapter_lock, flags); adapter = card->adapter; + if (!adapter || + adapter->hw_status == MWIFIEX_HW_STATUS_RESET || + adapter->hw_status == MWIFIEX_HW_STATUS_NOT_READY) { + spin_unlock_irqrestore(&card->adapter_lock, flags); + pr_err("Adapter structure is not valid or hw_status shows failure\n"); + return 0; + } if (adapter->hw_status == MWIFIEX_HW_STATUS_INITIALIZING || adapter->hw_status == MWIFIEX_HW_STATUS_INIT_DONE || adapter->hw_status == MWIFIEX_HW_STATUS_CLOSING) { + spin_unlock_irqrestore(&card->adapter_lock, flags); pr_err("We are in the middle of initialzaion or closing\n"); return -EBUSY; } + spin_unlock_irqrestore(&card->adapter_lock, flags); /* Enable the Host Sleep */ if (!mwifiex_enable_hs(adapter)) { @@ -150,16 +159,22 @@ static int mwifiex_pcie_resume(struct device *dev) struct mwifiex_adapter *adapter; struct pcie_service_card *card; struct pci_dev *pdev = to_pci_dev(dev); + unsigned long flags; card = pci_get_drvdata(pdev); - - if (!card || !card->adapter || - card->adapter->hw_status != MWIFIEX_HW_STATUS_READY) { - pr_err("Card or adapter structure is not valid or hw_status is not ready\n"); + if (!card) { + pr_err("Card is not valid\n"); return 0; } + spin_lock_irqsave(&card->adapter_lock, flags); adapter = card->adapter; + if (!adapter || adapter->hw_status != MWIFIEX_HW_STATUS_READY) { + spin_unlock_irqrestore(&card->adapter_lock, flags); + pr_err("adapter structure is not valid or hw_status is not ready\n"); + return 0; + } + spin_unlock_irqrestore(&card->adapter_lock, flags); if (!adapter->is_suspended) { mwifiex_dbg(adapter, WARN, @@ -195,6 +210,7 @@ static int mwifiex_pcie_probe(struct pci_dev *pdev, return -ENOMEM; card->dev = pdev; + spin_lock_init(&card->adapter_lock); if (ent->driver_data) { struct mwifiex_pcie_device *data = (void *)ent->driver_data; @@ -2973,9 +2989,12 @@ static int mwifiex_register_dev(struct mwifiex_adapter *adapter) { struct pcie_service_card *card = adapter->card; struct pci_dev *pdev = card->dev; + unsigned long flags; + spin_lock_irqsave(&card->adapter_lock, flags); /* save adapter pointer in card */ card->adapter = adapter; + spin_unlock_irqrestore(&card->adapter_lock, flags); adapter->dev = &pdev->dev; if (mwifiex_pcie_request_irq(adapter)) @@ -3001,6 +3020,7 @@ static void mwifiex_unregister_dev(struct mwifiex_adapter *adapter) struct pcie_service_card *card = adapter->card; struct pci_dev *pdev; int i; + unsigned long flags; if (card) { pdev = card->dev; @@ -3022,7 +3042,9 @@ static void mwifiex_unregister_dev(struct mwifiex_adapter *adapter) if (card->msi_enable) pci_disable_msi(pdev); } + spin_lock_irqsave(&card->adapter_lock, flags); card->adapter = NULL; + spin_unlock_irqrestore(&card->adapter_lock, flags); } } diff --git a/drivers/net/wireless/marvell/mwifiex/pcie.h b/drivers/net/wireless/marvell/mwifiex/pcie.h index 46f99ca..f6e20ea 100644 --- a/drivers/net/wireless/marvell/mwifiex/pcie.h +++ b/drivers/net/wireless/marvell/mwifiex/pcie.h @@ -344,6 +344,8 @@ struct mwifiex_msix_context { struct pcie_service_card { struct pci_dev *dev; struct mwifiex_adapter *adapter; + /* spin lock for card->adapter */ + spinlock_t adapter_lock; struct mwifiex_pcie_device pcie; u8 txbd_flush; -- 1.9.1