From patchwork Fri Aug 3 10:18:21 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guido Kiener X-Patchwork-Id: 10554835 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id DE6B29093 for ; Fri, 3 Aug 2018 09:21:08 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D7D792BE27 for ; Fri, 3 Aug 2018 09:21:08 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id CC4092C224; Fri, 3 Aug 2018 09:21:08 +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 A2ABC2BE27 for ; Fri, 3 Aug 2018 09:21:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732482AbeHCLQc (ORCPT ); Fri, 3 Aug 2018 07:16:32 -0400 Received: from mr08.mx01.tldhost.de ([84.19.26.246]:38977 "EHLO mr08.mx01.tldhost.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730129AbeHCLQb (ORCPT ); Fri, 3 Aug 2018 07:16:31 -0400 Received: from mx01.tldhost.de (localhost [127.0.0.1]) by mx01.tldhost.de (Postfix) with ESMTP id 57E17120EEB for ; Fri, 3 Aug 2018 11:21:04 +0200 (CEST) Received: by mx01.tldhost.de (Postfix, from userid 1001) id 45F93120EF4; Fri, 3 Aug 2018 11:21:04 +0200 (CEST) Received: from server12.tldhost.de (server12.tldhost.de [84.19.26.112]) by mx01.tldhost.de (Postfix) with ESMTPS id 33EA21200AC; Fri, 3 Aug 2018 11:21:02 +0200 (CEST) From: Guido Kiener To: gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, guido.kiener@rohde-schwarz.com, pankaj.adhikari@ni.com, steve_bayless@keysight.com, dpenkler@gmail.com Cc: Guido Kiener Subject: [PATCH v5 08/22] usb: usbtmc: Add ioctl USBTMC488_IOCTL_WAIT_SRQ Date: Fri, 3 Aug 2018 12:18:21 +0200 Message-Id: <20180803101835.4674-9-guido@kiener-muenchen.de> In-Reply-To: <20180803101835.4674-1-guido@kiener-muenchen.de> References: <20180803101835.4674-1-guido@kiener-muenchen.de> X-PPP-Message-ID: <20180803092102.8733.76906@server12.tldhost.de> X-PPP-Vhost: kiener-muenchen.de X-POWERED-BY: TLDHost.de - AV:CLEAN SPAM:OK 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 Wait until an SRQ (service request) is received on the interrupt pipe or until the given period of time is expired. In contrast to the poll() function this ioctl does not return when other (a)synchronous I/O operations fail with EPOLLERR. Signed-off-by: Guido Kiener Reviewed-by: Steve Bayless --- drivers/usb/class/usbtmc.c | 57 ++++++++++++++++++++++++++++++++++++ include/uapi/linux/usb/tmc.h | 1 + 2 files changed, 58 insertions(+) diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c index 9953b62b7db4..15421aa71eef 100644 --- a/drivers/usb/class/usbtmc.c +++ b/drivers/usb/class/usbtmc.c @@ -130,6 +130,7 @@ struct usbtmc_file_data { u32 timeout; u8 srq_byte; atomic_t srq_asserted; + atomic_t closing; u8 eom_val; u8 term_char; @@ -201,6 +202,8 @@ static int usbtmc_open(struct inode *inode, struct file *filp) mutex_lock(&data->io_mutex); file_data->data = data; + atomic_set(&file_data->closing, 0); + /* copy default values from device settings */ file_data->timeout = USBTMC_TIMEOUT; file_data->term_char = data->TermChar; @@ -231,6 +234,7 @@ static int usbtmc_flush(struct file *file, fl_owner_t id) if (file_data == NULL) return -ENODEV; + atomic_set(&file_data->closing, 1); data = file_data->data; /* wait for io to stop */ @@ -584,6 +588,54 @@ static int usbtmc488_ioctl_read_stb(struct usbtmc_file_data *file_data, return rv; } +static int usbtmc488_ioctl_wait_srq(struct usbtmc_file_data *file_data, + __u32 __user *arg) +{ + struct usbtmc_device_data *data = file_data->data; + struct device *dev = &data->intf->dev; + int rv; + u32 timeout; + unsigned long expire; + + if (!data->iin_ep_present) { + dev_dbg(dev, "no interrupt endpoint present\n"); + return -EFAULT; + } + + if (get_user(timeout, arg)) + return -EFAULT; + + expire = msecs_to_jiffies(timeout); + + mutex_unlock(&data->io_mutex); + + rv = wait_event_interruptible_timeout( + data->waitq, + atomic_read(&file_data->srq_asserted) != 0 || + atomic_read(&file_data->closing), + expire); + + mutex_lock(&data->io_mutex); + + /* Note! disconnect or close could be called in the meantime */ + if (atomic_read(&file_data->closing) || data->zombie) + rv = -ENODEV; + + if (rv < 0) { + /* dev can be invalid now! */ + pr_debug("%s - wait interrupted %d\n", __func__, rv); + return rv; + } + + if (rv == 0) { + dev_dbg(dev, "%s - wait timed out\n", __func__); + return -ETIMEDOUT; + } + + dev_dbg(dev, "%s - srq asserted\n", __func__); + return 0; +} + static int usbtmc488_ioctl_simple(struct usbtmc_device_data *data, void __user *arg, unsigned int cmd) { @@ -2150,6 +2202,11 @@ static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg) retval = usbtmc488_ioctl_trigger(file_data); break; + case USBTMC488_IOCTL_WAIT_SRQ: + retval = usbtmc488_ioctl_wait_srq(file_data, + (__u32 __user *)arg); + break; + case USBTMC_IOCTL_CANCEL_IO: retval = usbtmc_ioctl_cancel_io(file_data); break; diff --git a/include/uapi/linux/usb/tmc.h b/include/uapi/linux/usb/tmc.h index d638c198c7a8..56c76a9680e5 100644 --- a/include/uapi/linux/usb/tmc.h +++ b/include/uapi/linux/usb/tmc.h @@ -96,6 +96,7 @@ struct usbtmc_message { #define USBTMC488_IOCTL_GOTO_LOCAL _IO(USBTMC_IOC_NR, 20) #define USBTMC488_IOCTL_LOCAL_LOCKOUT _IO(USBTMC_IOC_NR, 21) #define USBTMC488_IOCTL_TRIGGER _IO(USBTMC_IOC_NR, 22) +#define USBTMC488_IOCTL_WAIT_SRQ _IOW(USBTMC_IOC_NR, 23, __u32) /* Cancel and cleanup asynchronous calls */ #define USBTMC_IOCTL_CANCEL_IO _IO(USBTMC_IOC_NR, 35)