From patchwork Thu Jul 2 16:29:49 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tony Lindgren X-Patchwork-Id: 11639565 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3133A161F for ; Thu, 2 Jul 2020 16:29:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1F3492084C for ; Thu, 2 Jul 2020 16:29:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726630AbgGBQ35 (ORCPT ); Thu, 2 Jul 2020 12:29:57 -0400 Received: from muru.com ([72.249.23.125]:60394 "EHLO muru.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726750AbgGBQ35 (ORCPT ); Thu, 2 Jul 2020 12:29:57 -0400 Received: from hillo.muru.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTP id 51FD980BB; Thu, 2 Jul 2020 16:30:50 +0000 (UTC) From: Tony Lindgren To: Kalle Valo Cc: Eyal Reizer , Guy Mishol , linux-wireless@vger.kernel.org, linux-omap@vger.kernel.org Subject: [PATCH 2/4] wlcore: Use spin_trylock in wlcore_irq_locked() for running the queue Date: Thu, 2 Jul 2020 09:29:49 -0700 Message-Id: <20200702162951.45392-3-tony@atomide.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200702162951.45392-1-tony@atomide.com> References: <20200702162951.45392-1-tony@atomide.com> MIME-Version: 1.0 Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org We currently have a collection of flags and locking between the threaded irq and tx work: - wl->flags bitops - wl->mutex - wl->wl_lock spinlock The bitops flags do not need a spinlock around them, and wlcore_irq() already holds the mutex calling wlcore_irq_locked(). And we only need the spinlock to see if we need to run the queue or not. To simplify the locking, we can use spin_trylock and always run the tx queue unless we know there's nothing to do. Signed-off-by: Tony Lindgren --- drivers/net/wireless/ti/wlcore/main.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) diff --git a/drivers/net/wireless/ti/wlcore/main.c b/drivers/net/wireless/ti/wlcore/main.c --- a/drivers/net/wireless/ti/wlcore/main.c +++ b/drivers/net/wireless/ti/wlcore/main.c @@ -521,6 +521,7 @@ static int wlcore_irq_locked(struct wl1271 *wl) int ret = 0; u32 intr; int loopcount = WL1271_IRQ_MAX_LOOPS; + bool run_tx_queue = true; bool done = false; unsigned int defer_count; unsigned long flags; @@ -586,19 +587,22 @@ static int wlcore_irq_locked(struct wl1271 *wl) goto err_ret; /* Check if any tx blocks were freed */ - spin_lock_irqsave(&wl->wl_lock, flags); - if (!test_bit(WL1271_FLAG_FW_TX_BUSY, &wl->flags) && - wl1271_tx_total_queue_count(wl) > 0) { - spin_unlock_irqrestore(&wl->wl_lock, flags); + if (!test_bit(WL1271_FLAG_FW_TX_BUSY, &wl->flags)) { + if (spin_trylock_irqsave(&wl->wl_lock, flags)) { + if (!wl1271_tx_total_queue_count(wl)) + run_tx_queue = false; + spin_unlock_irqrestore(&wl->wl_lock, flags); + } + /* * In order to avoid starvation of the TX path, * call the work function directly. */ - ret = wlcore_tx_work_locked(wl); - if (ret < 0) - goto err_ret; - } else { - spin_unlock_irqrestore(&wl->wl_lock, flags); + if (run_tx_queue) { + ret = wlcore_tx_work_locked(wl); + if (ret < 0) + goto err_ret; + } } /* check for tx results */