Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932283AbaF3MTb (ORCPT ); Mon, 30 Jun 2014 08:19:31 -0400 Received: from ip4-83-240-18-248.cust.nbox.cz ([83.240.18.248]:51966 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753204AbaF3LxZ (ORCPT ); Mon, 30 Jun 2014 07:53:25 -0400 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Johan Hovold , Jiri Slaby Subject: [PATCH 3.12 060/181] USB: cdc-acm: fix broken runtime suspend Date: Mon, 30 Jun 2014 13:51:21 +0200 Message-Id: <1effe732d46d18b95d3f7c635997a084c8cd4c19.1404128998.git.jslaby@suse.cz> X-Mailer: git-send-email 2.0.0 In-Reply-To: <61844d8e25eb8899b0836afa9796fa239db80f1f.1404128997.git.jslaby@suse.cz> References: <61844d8e25eb8899b0836afa9796fa239db80f1f.1404128997.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Johan Hovold 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit 140cb81ac8c625942a1d695875932c615767a526 upstream. The current ACM runtime-suspend implementation is broken in several ways: Firstly, it buffers only the first write request being made while suspended -- any further writes are silently dropped. Secondly, writes being dropped also leak write urbs, which are never reclaimed (until the device is unbound). Thirdly, even the single buffered write is not cleared at shutdown (which may happen before the device is resumed), something which can lead to another urb leak as well as a PM usage-counter leak. Fix this by implementing a delayed-write queue using urb anchors and making sure to discard the queue properly at shutdown. Fixes: 11ea859d64b6 ("USB: additional power savings for cdc-acm devices that support remote wakeup") Reported-by: Xiao Jin Signed-off-by: Johan Hovold Signed-off-by: Jiri Slaby --- drivers/usb/class/cdc-acm.c | 32 ++++++++++++++++++++++---------- drivers/usb/class/cdc-acm.h | 2 +- 2 files changed, 23 insertions(+), 11 deletions(-) diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 19263a3f3d0d..d9e346cf1eb8 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -559,6 +559,8 @@ static void acm_port_destruct(struct tty_port *port) static void acm_port_shutdown(struct tty_port *port) { struct acm *acm = container_of(port, struct acm, port); + struct urb *urb; + struct acm_wb *wb; int i; dev_dbg(&acm->control->dev, "%s\n", __func__); @@ -567,6 +569,16 @@ static void acm_port_shutdown(struct tty_port *port) if (!acm->disconnected) { usb_autopm_get_interface(acm->control); acm_set_control(acm, acm->ctrlout = 0); + + for (;;) { + urb = usb_get_from_anchor(&acm->delayed); + if (!urb) + break; + wb = urb->context; + wb->use = 0; + usb_autopm_put_interface_async(acm->control); + } + usb_kill_urb(acm->ctrlurb); for (i = 0; i < ACM_NW; i++) usb_kill_urb(acm->wb[i].urb); @@ -634,12 +646,9 @@ static int acm_tty_write(struct tty_struct *tty, usb_autopm_get_interface_async(acm->control); if (acm->susp_count) { - if (!acm->delayed_wb) - acm->delayed_wb = wb; - else - usb_autopm_put_interface_async(acm->control); + usb_anchor_urb(wb->urb, &acm->delayed); spin_unlock_irqrestore(&acm->write_lock, flags); - return count; /* A white lie */ + return count; } usb_mark_last_busy(acm->dev); @@ -1176,6 +1185,7 @@ made_compressed_probe: acm->bInterval = epread->bInterval; tty_port_init(&acm->port); acm->port.ops = &acm_port_ops; + init_usb_anchor(&acm->delayed); buf = usb_alloc_coherent(usb_dev, ctrlsize, GFP_KERNEL, &acm->ctrl_dma); if (!buf) { @@ -1445,7 +1455,7 @@ static int acm_suspend(struct usb_interface *intf, pm_message_t message) static int acm_resume(struct usb_interface *intf) { struct acm *acm = usb_get_intfdata(intf); - struct acm_wb *wb; + struct urb *urb; int rv = 0; spin_lock_irq(&acm->read_lock); @@ -1457,10 +1467,12 @@ static int acm_resume(struct usb_interface *intf) if (test_bit(ASYNCB_INITIALIZED, &acm->port.flags)) { rv = usb_submit_urb(acm->ctrlurb, GFP_ATOMIC); - if (acm->delayed_wb) { - wb = acm->delayed_wb; - acm->delayed_wb = NULL; - acm_start_wb(acm, wb); + for (;;) { + urb = usb_get_from_anchor(&acm->delayed); + if (!urb) + break; + + acm_start_wb(acm, urb->context); } /* diff --git a/drivers/usb/class/cdc-acm.h b/drivers/usb/class/cdc-acm.h index 0f76e4af600e..1683ac161cf6 100644 --- a/drivers/usb/class/cdc-acm.h +++ b/drivers/usb/class/cdc-acm.h @@ -117,7 +117,7 @@ struct acm { unsigned int throttled:1; /* actually throttled */ unsigned int throttle_req:1; /* throttle requested */ u8 bInterval; - struct acm_wb *delayed_wb; /* write queued for a device about to be woken */ + struct usb_anchor delayed; /* writes queued for a device about to be woken */ }; #define CDC_DATA_INTERFACE_TYPE 0x0a -- 2.0.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/