From patchwork Wed Jun 15 12:46:26 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Jander X-Patchwork-Id: 12882286 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E1C75C433EF for ; Wed, 15 Jun 2022 12:47:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347058AbiFOMrw (ORCPT ); Wed, 15 Jun 2022 08:47:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52906 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240141AbiFOMrs (ORCPT ); Wed, 15 Jun 2022 08:47:48 -0400 Received: from smtp28.bhosted.nl (smtp28.bhosted.nl [IPv6:2a02:9e0:8000::40]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DF133CE3F for ; Wed, 15 Jun 2022 05:47:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonic.nl; s=202111; h=content-transfer-encoding:mime-version:references:in-reply-to:message-id:date: subject:cc:to:from:from; bh=H4ti9M99B6lVzGb3ljKte2Ib95Nd6XVISFe9+7VW/Zk=; b=csPsaBko5bqW0jnrIaHfKi3+Z5DJAZ8WbhODSg9hG9pCzfdJ01wrdO4sQDT2lCNvq8654L0m+CZbv 4UEULy56FxWQjBKwaX/K7dNKeaoEPE6qyDT0NOgmTd/54a4hVQytsBU4V0G6Yxsb7+6ORUU9pCgKJU 5Vhn38fiEJxz4fAYjzMi1mHlTeuYLQGBAQbPi6PQh+7JrrRPX5rwaRcMmaeSM8VIK/eNP41OKuIa34 gsNQPstMugQVhWdVMXlYcUgPQW/tXaBViJjudEL+E+gKt5AKjxNfHOVube2HNaI9i44A0812h7yjkK yEvcQRd/c1OymRWNYHpf90V23Fz2Qcw== X-MSG-ID: 532cb81f-eca9-11ec-8a45-0050569d11ae From: David Jander To: Mark Brown Cc: linux-spi@vger.kernel.org, Marc Kleine-Budde , Andrew Lunn , David Jander Subject: [RFC] [PATCH v2 03/11] spi: Lock controller idling transition inside the io_mutex Date: Wed, 15 Jun 2022 14:46:26 +0200 Message-Id: <20220615124634.3302867-4-david@protonic.nl> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220615124634.3302867-1-david@protonic.nl> References: <20220615124634.3302867-1-david@protonic.nl> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org This way, the spi sync path does not need to deal with the idling transition. Signed-off-by: David Jander --- drivers/spi/spi.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 2d057d03c4f7..cfff2ff96fa0 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1643,27 +1643,30 @@ static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread) unsigned long flags; int ret; + /* Take the IO mutex */ + mutex_lock(&ctlr->io_mutex); + /* Lock queue */ spin_lock_irqsave(&ctlr->queue_lock, flags); /* Make sure we are not already running a message */ if (ctlr->cur_msg) { spin_unlock_irqrestore(&ctlr->queue_lock, flags); - return; + goto out_unlock; } /* If another context is idling the device then defer */ if (ctlr->idling) { kthread_queue_work(ctlr->kworker, &ctlr->pump_messages); spin_unlock_irqrestore(&ctlr->queue_lock, flags); - return; + goto out_unlock; } /* Check if the queue is idle */ if (list_empty(&ctlr->queue) || !ctlr->running) { if (!ctlr->busy) { spin_unlock_irqrestore(&ctlr->queue_lock, flags); - return; + goto out_unlock; } /* Defer any non-atomic teardown to the thread */ @@ -1679,7 +1682,7 @@ static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread) &ctlr->pump_messages); } spin_unlock_irqrestore(&ctlr->queue_lock, flags); - return; + goto out_unlock; } ctlr->busy = false; @@ -1701,7 +1704,7 @@ static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread) ctlr->idling = false; ctlr->queue_empty = true; spin_unlock_irqrestore(&ctlr->queue_lock, flags); - return; + goto out_unlock; } /* Extract head of queue */ @@ -1715,13 +1718,16 @@ static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread) ctlr->busy = true; spin_unlock_irqrestore(&ctlr->queue_lock, flags); - mutex_lock(&ctlr->io_mutex); ret = __spi_pump_transfer_message(ctlr, msg, was_busy); mutex_unlock(&ctlr->io_mutex); /* Prod the scheduler in case transfer_one() was busy waiting */ if (!ret) cond_resched(); + return; + +out_unlock: + mutex_unlock(&ctlr->io_mutex); } /**