{"id":833402,"url":"http://patchwork.ozlabs.org/api/1.2/patches/833402/?format=json","web_url":"http://patchwork.ozlabs.org/project/linux-pci/patch/20171102151206.tvfsotckcqgnj3ky@linutronix.de/","project":{"id":28,"url":"http://patchwork.ozlabs.org/api/1.2/projects/28/?format=json","name":"Linux PCI development","link_name":"linux-pci","list_id":"linux-pci.vger.kernel.org","list_email":"linux-pci@vger.kernel.org","web_url":null,"scm_url":null,"webscm_url":null,"list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<20171102151206.tvfsotckcqgnj3ky@linutronix.de>","list_archive_url":null,"date":"2017-11-02T15:12:06","name":"[v3] pci/switchtec: Don't use completion's wait queue","commit_ref":null,"pull_url":null,"state":"not-applicable","archived":false,"hash":"edfb1becf4005ea1ac6aed5fdbd89483103065ac","submitter":{"id":86,"url":"http://patchwork.ozlabs.org/api/1.2/people/86/?format=json","name":"Sebastian Andrzej Siewior","email":"bigeasy@linutronix.de"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/linux-pci/patch/20171102151206.tvfsotckcqgnj3ky@linutronix.de/mbox/","series":[{"id":11529,"url":"http://patchwork.ozlabs.org/api/1.2/series/11529/?format=json","web_url":"http://patchwork.ozlabs.org/project/linux-pci/list/?series=11529","date":"2017-11-02T15:12:06","name":"[v3] pci/switchtec: Don't use completion's wait queue","version":3,"mbox":"http://patchwork.ozlabs.org/series/11529/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/833402/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/833402/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@bilbo.ozlabs.org","Authentication-Results":"ozlabs.org;\n\tspf=none (mailfrom) smtp.mailfrom=vger.kernel.org\n\t(client-ip=209.132.180.67; helo=vger.kernel.org;\n\tenvelope-from=linux-pci-owner@vger.kernel.org;\n\treceiver=)","Received":["from vger.kernel.org (vger.kernel.org [209.132.180.67])\n\tby ozlabs.org (Postfix) with ESMTP id 3yST8V0Ysnz9sDB\n\tfor ;\n\tFri, 3 Nov 2017 02:12:10 +1100 (AEDT)","(majordomo@vger.kernel.org) by vger.kernel.org via listexpand\n\tid S933593AbdKBPMI convert rfc822-to-8bit (ORCPT\n\t);\n\tThu, 2 Nov 2017 11:12:08 -0400","from Galois.linutronix.de ([146.0.238.70]:54675 \"EHLO\n\tGalois.linutronix.de\" rhost-flags-OK-OK-OK-OK) by vger.kernel.org\n\twith ESMTP id S932724AbdKBPMI (ORCPT\n\t); Thu, 2 Nov 2017 11:12:08 -0400","from bigeasy by Galois.linutronix.de with local (Exim 4.80)\n\t(envelope-from )\n\tid 1eAH9g-0000D7-JT; Thu, 02 Nov 2017 16:11:40 +0100"],"Date":"Thu, 2 Nov 2017 16:12:06 +0100","From":"Sebastian Andrzej Siewior ","To":"Logan Gunthorpe ","Cc":"linux-pci@vger.kernel.org, tglx@linutronix.de,\n\tKurt Schwemmer ","Subject":"[PATCH v3] pci/switchtec: Don't use completion's wait queue","Message-ID":"<20171102151206.tvfsotckcqgnj3ky@linutronix.de>","References":"<20171004095007.19148-1-bigeasy@linutronix.de>\n\t\n\t<20171005105100.2nf4ih2fgq6dax5g@linutronix.de>\n\t<0ae3975a-b1b1-fb8b-2f90-ff103da9d178@deltatee.com>","MIME-Version":"1.0","Content-Type":"text/plain; charset=utf-8","Content-Disposition":"inline","Content-Transfer-Encoding":"8BIT","In-Reply-To":"<0ae3975a-b1b1-fb8b-2f90-ff103da9d178@deltatee.com>","User-Agent":"NeoMutt/20170609 (1.8.3)","Sender":"linux-pci-owner@vger.kernel.org","Precedence":"bulk","List-ID":"","X-Mailing-List":"linux-pci@vger.kernel.org"},"content":"The poll callback is using completion's wait_queue_head_t member and\nputs it in poll_wait() so the poll() caller gets a wakeup after command\ncompleted. This does not work on RT because we don't have a\nwait_queue_head_t in our completion implementation. Nobody in tree does\nlike that in tree so this is the only driver that breaks.\n\nInstead of using the completion here is waitqueue with a status flag as\nsuggested by Logan.\n\nI don't have the HW so I have no idea if it works as expected, so please\ntest it.\n\nCc: Kurt Schwemmer \nCc: Logan Gunthorpe \nSigned-off-by: Sebastian Andrzej Siewior \n---\nv2…v3: add missing\n\t stuser->cmd_done = true;\n spotted by Logan.\n\n drivers/pci/switch/switchtec.c | 22 +++++++++++++---------\n 1 file changed, 13 insertions(+), 9 deletions(-)","diff":"--- a/drivers/pci/switch/switchtec.c\n+++ b/drivers/pci/switch/switchtec.c\n@@ -306,10 +306,11 @@ struct switchtec_user {\n \n \tenum mrpc_state state;\n \n-\tstruct completion comp;\n+\twait_queue_head_t cmd_comp;\n \tstruct kref kref;\n \tstruct list_head list;\n \n+\tbool cmd_done;\n \tu32 cmd;\n \tu32 status;\n \tu32 return_code;\n@@ -331,7 +332,7 @@ static struct switchtec_user *stuser_cre\n \tstuser->stdev = stdev;\n \tkref_init(&stuser->kref);\n \tINIT_LIST_HEAD(&stuser->list);\n-\tinit_completion(&stuser->comp);\n+\tinit_waitqueue_head(&stuser->cmd_comp);\n \tstuser->event_cnt = atomic_read(&stdev->event_cnt);\n \n \tdev_dbg(&stdev->dev, \"%s: %p\\n\", __func__, stuser);\n@@ -414,7 +415,7 @@ static int mrpc_queue_cmd(struct switcht\n \tkref_get(&stuser->kref);\n \tstuser->read_len = sizeof(stuser->data);\n \tstuser_set_state(stuser, MRPC_QUEUED);\n-\tinit_completion(&stuser->comp);\n+\tstuser->cmd_done = false;\n \tlist_add_tail(&stuser->list, &stdev->mrpc_queue);\n \n \tmrpc_cmd_submit(stdev);\n@@ -451,7 +452,8 @@ static void mrpc_complete_cmd(struct swi\n \t\t stuser->read_len);\n \n out:\n-\tcomplete_all(&stuser->comp);\n+\tstuser->cmd_done = true;\n+\twake_up_interruptible(&stuser->cmd_comp);\n \tlist_del_init(&stuser->list);\n \tstuser_put(stuser);\n \tstdev->mrpc_busy = 0;\n@@ -721,10 +723,11 @@ static ssize_t switchtec_dev_read(struct\n \tmutex_unlock(&stdev->mrpc_mutex);\n \n \tif (filp->f_flags & O_NONBLOCK) {\n-\t\tif (!try_wait_for_completion(&stuser->comp))\n+\t\tif (!stuser->cmd_done)\n \t\t\treturn -EAGAIN;\n \t} else {\n-\t\trc = wait_for_completion_interruptible(&stuser->comp);\n+\t\trc = wait_event_interruptible(stuser->cmd_comp,\n+\t\t\t\t\t stuser->cmd_done);\n \t\tif (rc < 0)\n \t\t\treturn rc;\n \t}\n@@ -772,7 +775,7 @@ static unsigned int switchtec_dev_poll(s\n \tstruct switchtec_dev *stdev = stuser->stdev;\n \tint ret = 0;\n \n-\tpoll_wait(filp, &stuser->comp.wait, wait);\n+\tpoll_wait(filp, &stuser->cmd_comp, wait);\n \tpoll_wait(filp, &stdev->event_wq, wait);\n \n \tif (lock_mutex_and_test_alive(stdev))\n@@ -780,7 +783,7 @@ static unsigned int switchtec_dev_poll(s\n \n \tmutex_unlock(&stdev->mrpc_mutex);\n \n-\tif (try_wait_for_completion(&stuser->comp))\n+\tif (stuser->cmd_done)\n \t\tret |= POLLIN | POLLRDNORM;\n \n \tif (stuser->event_cnt != atomic_read(&stdev->event_cnt))\n@@ -1255,7 +1258,8 @@ static void stdev_kill(struct switchtec_\n \n \t/* Wake up and kill any users waiting on an MRPC request */\n \tlist_for_each_entry_safe(stuser, tmpuser, &stdev->mrpc_queue, list) {\n-\t\tcomplete_all(&stuser->comp);\n+\t\tstuser->cmd_done = true;\n+\t\twake_up_interruptible(&stuser->cmd_comp);\n \t\tlist_del_init(&stuser->list);\n \t\tstuser_put(stuser);\n \t}\n","prefixes":["v3"]}