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 X-Spam-Level: X-Spam-Status: No, score=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_NEOMUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DB134C3279B for ; Mon, 2 Jul 2018 07:31:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9F5B924FBF for ; Mon, 2 Jul 2018 07:31:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9F5B924FBF Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linutronix.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753999AbeGBHbk convert rfc822-to-8bit (ORCPT ); Mon, 2 Jul 2018 03:31:40 -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-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8BIT In-Reply-To: <20180702062442.GD9802@localhost> User-Agent: NeoMutt/20180512 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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) -- 2.18.0 From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Subject: [v2] mfd: dln2: use irqsave() in USB's complete callback From: Sebastian Andrzej Siewior Message-Id: <20180702073132.vrbvrdrht3ipwhq7@linutronix.de> Date: Mon, 2 Jul 2018 09:31:32 +0200 To: Johan Hovold Cc: Octavian Purdila , lkml , linux-usb@vger.kernel.org, tglx@linutronix.de, Lee Jones List-ID: VGhlIFVTQiBjb21wbGV0aW9uIGNhbGxiYWNrIGRvZXMgbm90IGRpc2FibGUgaW50ZXJydXB0cyB3 aGlsZSBhY3F1aXJpbmcKdGhlIGxvY2suIFdlIHdhbnQgdG8gcmVtb3ZlIHRoZSBsb2NhbF9pcnFf ZGlzYWJsZSgpIGludm9jYXRpb24gZnJvbQpfX3VzYl9oY2RfZ2l2ZWJhY2tfdXJiKCkgYW5kIHRo ZXJlZm9yZSBpdCBpcyByZXF1aXJlZCBmb3IgdGhlIGNhbGxiYWNrCmhhbmRsZXIgdG8gZGlzYWJs ZSB0aGUgaW50ZXJydXB0cyB3aGlsZSBhY3F1aXJpbmcgdGhlIGxvY2suClRoZSBjYWxsYmFjayBt YXkgYmUgaW52b2tlZCBlaXRoZXIgaW4gSVJRIG9yIEJIIGNvbnRleHQgZGVwZW5kaW5nIG9uIHRo ZQpVU0IgaG9zdCBjb250cm9sbGVyLgpVc2UgdGhlIF9pcnFzYXZlKCkgdmFyaWFudCBvZiB0aGUg bG9ja2luZyBwcmltaXRpdmVzLgoKQ2M6IExlZSBKb25lcyA8bGVlLmpvbmVzQGxpbmFyby5vcmc+ CkNjOiBPY3RhdmlhbiBQdXJkaWxhIDx0YXZpQGNzLnB1Yi5ybz4KUmV2aWV3ZWQtYnk6IEpvaGFu IEhvdm9sZCA8am9oYW5Aa2VybmVsLm9yZz4KU2lnbmVkLW9mZi1ieTogU2ViYXN0aWFuIEFuZHJ6 ZWogU2lld2lvciA8YmlnZWFzeUBsaW51dHJvbml4LmRlPgotLS0KdjHigKZ2MjogUmVtb3ZlIGFs c28gdGhlIGNvbW1lbnQgdGhhdCBzYXlzIHRoYXQgdGhlcmUgaXMgbm8gbmVlZCB0bwogICAgICAg ZGlzYWJsZSBpbnRlcnJ1cHRzLgoKIGRyaXZlcnMvbWZkL2RsbjIuYyB8IDEwICsrKy0tLS0tLS0K IDEgZmlsZSBjaGFuZ2VkLCAzIGluc2VydGlvbnMoKyksIDcgZGVsZXRpb25zKC0pCgpkaWZmIC0t Z2l0IGEvZHJpdmVycy9tZmQvZGxuMi5jIGIvZHJpdmVycy9tZmQvZGxuMi5jCmluZGV4IDcwNGUx ODljYTE2Mi4uOTBlNzg5OTQzNDY2IDEwMDY0NAotLS0gYS9kcml2ZXJzL21mZC9kbG4yLmMKKysr IGIvZHJpdmVycy9tZmQvZGxuMi5jCkBAIC0xOTQsNiArMTk0LDcgQEAgc3RhdGljIGJvb2wgZGxu Ml90cmFuc2Zlcl9jb21wbGV0ZShzdHJ1Y3QgZGxuMl9kZXYgKmRsbjIsIHN0cnVjdCB1cmIgKnVy YiwKIAlzdHJ1Y3QgZGV2aWNlICpkZXYgPSAmZGxuMi0+aW50ZXJmYWNlLT5kZXY7CiAJc3RydWN0 IGRsbjJfbW9kX3J4X3Nsb3RzICpyeHMgPSAmZGxuMi0+bW9kX3J4X3Nsb3RzW2hhbmRsZV07CiAJ c3RydWN0IGRsbjJfcnhfY29udGV4dCAqcnhjOworCXVuc2lnbmVkIGxvbmcgZmxhZ3M7CiAJYm9v bCB2YWxpZF9zbG90ID0gZmFsc2U7CiAKIAlpZiAocnhfc2xvdCA+PSBETE4yX01BWF9SWF9TTE9U UykKQEAgLTIwMSwxOCArMjAyLDEzIEBAIHN0YXRpYyBib29sIGRsbjJfdHJhbnNmZXJfY29tcGxl dGUoc3RydWN0IGRsbjJfZGV2ICpkbG4yLCBzdHJ1Y3QgdXJiICp1cmIsCiAKIAlyeGMgPSAmcnhz LT5zbG90c1tyeF9zbG90XTsKIAotCS8qCi0JICogTm8gbmVlZCB0byBkaXNhYmxlIGludGVycnVw dHMgYXMgdGhpcyBsb2NrIGlzIG5vdCB0YWtlbiBpbiBpbnRlcnJ1cHQKLQkgKiBjb250ZXh0IGVs c2V3aGVyZSBpbiB0aGlzIGRyaXZlci4gVGhpcyBmdW5jdGlvbiAob3IgaXRzIGNhbGxlcnMpIGFy ZQotCSAqIGFsc28gbm90IGV4cG9ydGVkIHRvIG90aGVyIG1vZHVsZXMuCi0JICovCi0Jc3Bpbl9s b2NrKCZyeHMtPmxvY2spOworCXNwaW5fbG9ja19pcnFzYXZlKCZyeHMtPmxvY2ssIGZsYWdzKTsK IAlpZiAocnhjLT5pbl91c2UgJiYgIXJ4Yy0+dXJiKSB7CiAJCXJ4Yy0+dXJiID0gdXJiOwogCQlj b21wbGV0ZSgmcnhjLT5kb25lKTsKIAkJdmFsaWRfc2xvdCA9IHRydWU7CiAJfQotCXNwaW5fdW5s b2NrKCZyeHMtPmxvY2spOworCXNwaW5fdW5sb2NrX2lycXJlc3RvcmUoJnJ4cy0+bG9jaywgZmxh Z3MpOwogCiBvdXQ6CiAJaWYgKCF2YWxpZF9zbG90KQo=