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Date:   Mon, 18 Jul 2022 18:26:54 -0700
Message-Id: <2562ea25269c4af173382c6e03fde9d423f664d4.1658192351.git.Thinh.Nguyen@synopsys.com>
In-Reply-To: <cover.1658192351.git.Thinh.Nguyen@synopsys.com>
References: <cover.1658192351.git.Thinh.Nguyen@synopsys.com>
From:   Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Subject: [PATCH v2 08/25] usb: gadget: f_tcm: Handle multiple commands in parallel
To:     Felipe Balbi <balbi@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Thinh Nguyen <Thinh.Nguyen@synopsys.com>,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        Dmitry Bogdanov <d.bogdanov@yadro.com>
Cc:     linux-scsi@vger.kernel.org, target-devel@vger.kernel.org
Precedence: bulk

Resubmit command on completion to fetch more commands and service them
in parallel. Increase the number of work in a queue. Each work will be
for each command allowing them to be processed concurrently. Also, set
them to be unbounded by cpu to improve performance.

Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
---
 Changes in v2:
 - None

 drivers/usb/gadget/function/f_tcm.c | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/drivers/usb/gadget/function/f_tcm.c b/drivers/usb/gadget/function/f_tcm.c
index 6e0b54985932..91d853682468 100644
--- a/drivers/usb/gadget/function/f_tcm.c
+++ b/drivers/usb/gadget/function/f_tcm.c
@@ -728,21 +728,16 @@ static int usbg_submit_command(struct f_uas *, struct usb_request *);
 static void uasp_cmd_complete(struct usb_ep *ep, struct usb_request *req)
 {
 	struct f_uas *fu = req->context;
-	int ret;
 
-	if (req->status < 0)
+	if (req->status == -ESHUTDOWN)
 		return;
 
-	ret = usbg_submit_command(fu, req);
-	/*
-	 * Once we tune for performance enqueue the command req here again so
-	 * we can receive a second command while we processing this one. Pay
-	 * attention to properly sync STAUS endpoint with DATA IN + OUT so you
-	 * don't break HS.
-	 */
-	if (!ret)
+	if (req->status < 0) {
+		usb_ep_queue(fu->ep_cmd, req, GFP_ATOMIC);
 		return;
-	usb_ep_queue(fu->ep_cmd, req, GFP_ATOMIC);
+	}
+
+	usbg_submit_command(fu, req);
 }
 
 static int uasp_alloc_stream_res(struct f_uas *fu, struct uas_stream *stream)
@@ -1357,7 +1352,8 @@ static struct se_portal_group *usbg_make_tpg(struct se_wwn *wwn,
 		goto unref_dep;
 	mutex_init(&tpg->tpg_mutex);
 	atomic_set(&tpg->tpg_port_count, 0);
-	tpg->workqueue = alloc_workqueue("tcm_usb_gadget", 0, 1);
+	tpg->workqueue = alloc_workqueue("tcm_usb_gadget",
+					 WQ_UNBOUND, WQ_UNBOUND_MAX_ACTIVE);
 	if (!tpg->workqueue)
 		goto free_tpg;
 
-- 
2.28.0