From patchwork Mon Jul 2 07:31:32 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sebastian Andrzej Siewior X-Patchwork-Id: 10500591 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 8B71D60362 for ; Mon, 2 Jul 2018 07:31:54 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6FD64283F9 for ; Mon, 2 Jul 2018 07:31:54 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6020528446; Mon, 2 Jul 2018 07:31:54 +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=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham 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 F0454283F9 for ; Mon, 2 Jul 2018 07:31:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753361AbeGBHbh convert rfc822-to-8bit (ORCPT ); Mon, 2 Jul 2018 03:31:37 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:36786 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752759AbeGBHbh (ORCPT ); Mon, 2 Jul 2018 03:31:37 -0400 Received: from bigeasy by Galois.linutronix.de with local (Exim 4.80) (envelope-from ) id 1fZtJ7-00043x-HF; Mon, 02 Jul 2018 09:31:33 +0200 Date: Mon, 2 Jul 2018 09:31:32 +0200 From: Sebastian Andrzej Siewior To: Johan Hovold Cc: Octavian Purdila , lkml , linux-usb@vger.kernel.org, tglx@linutronix.de, Lee Jones Subject: [PATCH v2] mfd: dln2: use irqsave() in USB's complete callback Message-ID: <20180702073132.vrbvrdrht3ipwhq7@linutronix.de> References: <20180701154108.13233-1-bigeasy@linutronix.de> <20180702062442.GD9802@localhost> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20180702062442.GD9802@localhost> User-Agent: NeoMutt/20180512 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The USB completion callback does not disable interrupts while acquiring the lock. We want to remove the local_irq_disable() invocation from __usb_hcd_giveback_urb() and therefore it is required for the callback handler to disable the interrupts while acquiring the lock. The callback may be invoked either in IRQ or BH context depending on the USB host controller. Use the _irqsave() variant of the locking primitives. Cc: Lee Jones Cc: Octavian Purdila Reviewed-by: Johan Hovold Signed-off-by: Sebastian Andrzej Siewior --- v1…v2: Remove also the comment that says that there is no need to disable interrupts. drivers/mfd/dln2.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/drivers/mfd/dln2.c b/drivers/mfd/dln2.c index 704e189ca162..90e789943466 100644 --- a/drivers/mfd/dln2.c +++ b/drivers/mfd/dln2.c @@ -194,6 +194,7 @@ static bool dln2_transfer_complete(struct dln2_dev *dln2, struct urb *urb, struct device *dev = &dln2->interface->dev; struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[handle]; struct dln2_rx_context *rxc; + unsigned long flags; bool valid_slot = false; if (rx_slot >= DLN2_MAX_RX_SLOTS) @@ -201,18 +202,13 @@ static bool dln2_transfer_complete(struct dln2_dev *dln2, struct urb *urb, rxc = &rxs->slots[rx_slot]; - /* - * No need to disable interrupts as this lock is not taken in interrupt - * context elsewhere in this driver. This function (or its callers) are - * also not exported to other modules. - */ - spin_lock(&rxs->lock); + spin_lock_irqsave(&rxs->lock, flags); if (rxc->in_use && !rxc->urb) { rxc->urb = urb; complete(&rxc->done); valid_slot = true; } - spin_unlock(&rxs->lock); + spin_unlock_irqrestore(&rxs->lock, flags); out: if (!valid_slot)