From patchwork Sat Jun 18 16:26:59 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sebastian Reichel X-Patchwork-Id: 9185731 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 8BDFC6075F for ; Sat, 18 Jun 2016 16:31:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7CB7028356 for ; Sat, 18 Jun 2016 16:31:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 71B6028365; Sat, 18 Jun 2016 16:31:28 +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=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable 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 1D6B228356 for ; Sat, 18 Jun 2016 16:31:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751656AbcFRQ2Q (ORCPT ); Sat, 18 Jun 2016 12:28:16 -0400 Received: from mail.kernel.org ([198.145.29.136]:50638 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751536AbcFRQ2O (ORCPT ); Sat, 18 Jun 2016 12:28:14 -0400 Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id E71BA2013D; Sat, 18 Jun 2016 16:28:12 +0000 (UTC) Received: from mail.kernel.org (unknown [178.162.198.111]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 66FC120165; Sat, 18 Jun 2016 16:28:11 +0000 (UTC) From: Sebastian Reichel To: Sebastian Reichel , linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Tony Lindgren , Aaro Koskinen , Pavel Machek , Ivaylo Dimitrov , =?UTF-8?q?Pali=20Roh=C3=A1r?= Subject: [RFC 09/19] HSI: omap_ssi_port: prepare start_tx/stop_tx for blocking pm_runtime calls Date: Sat, 18 Jun 2016 18:26:59 +0200 Message-Id: <1466267229-25012-10-git-send-email-sre@kernel.org> X-Mailer: git-send-email 2.8.1 In-Reply-To: <1466267229-25012-1-git-send-email-sre@kernel.org> References: <1466267229-25012-1-git-send-email-sre@kernel.org> X-Virus-Scanned: ClamAV using ClamSMTP Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP ssi_start_tx and ssi_stop_tx may be called from atomic context. Once pm_runtime_irq_safe() is removed for omap-ssi, this will fail, due to blocking pm_runtime_*_sync() calls. This fixes ssi_stop_tx by using non-sync API and ssi_start_tx by using a worker thread. Signed-off-by: Sebastian Reichel --- drivers/hsi/controllers/omap_ssi.h | 2 ++ drivers/hsi/controllers/omap_ssi_port.c | 23 ++++++++++++++++++----- 2 files changed, 20 insertions(+), 5 deletions(-) diff --git a/drivers/hsi/controllers/omap_ssi.h b/drivers/hsi/controllers/omap_ssi.h index 6cdaad8805f7..5467f61e5086 100644 --- a/drivers/hsi/controllers/omap_ssi.h +++ b/drivers/hsi/controllers/omap_ssi.h @@ -79,6 +79,7 @@ struct omap_ssm_ctx { * @pio_tasklet: Bottom half for PIO transfers and events * @flags: flags to keep track of states * @wk_refcount: Reference count for output wake line + * @work: worker for starting TX * @sys_mpu_enable: Context for the interrupt enable register for irq 0 * @sst: Context for the synchronous serial transmitter * @ssr: Context for the synchronous serial receiver @@ -103,6 +104,7 @@ struct omap_ssi_port { bool wktest:1; /* FIXME: HACK to be removed */ unsigned long flags; unsigned int wk_refcount; + struct work_struct work; /* OMAP SSI port context */ u32 sys_mpu_enable; /* We use only one irq */ struct omap_ssm_ctx sst; diff --git a/drivers/hsi/controllers/omap_ssi_port.c b/drivers/hsi/controllers/omap_ssi_port.c index 0d3452393670..cc56d0ee82a2 100644 --- a/drivers/hsi/controllers/omap_ssi_port.c +++ b/drivers/hsi/controllers/omap_ssi_port.c @@ -567,12 +567,22 @@ static int ssi_flush(struct hsi_client *cl) return 0; } +static void start_tx_work(struct work_struct *work) +{ + struct omap_ssi_port *omap_port = + container_of(work, struct omap_ssi_port, work); + struct hsi_port *port = to_hsi_port(omap_port->dev); + struct hsi_controller *ssi = to_hsi_controller(port->device.parent); + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + + pm_runtime_get_sync(omap_port->pdev); /* Grab clocks */ + writel(SSI_WAKE(0), omap_ssi->sys + SSI_SET_WAKE_REG(port->num)); +} + static int ssi_start_tx(struct hsi_client *cl) { struct hsi_port *port = hsi_get_port(cl); struct omap_ssi_port *omap_port = hsi_port_drvdata(port); - struct hsi_controller *ssi = to_hsi_controller(port->device.parent); - struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); dev_dbg(&port->device, "Wake out high %d\n", omap_port->wk_refcount); @@ -581,10 +591,10 @@ static int ssi_start_tx(struct hsi_client *cl) spin_unlock_bh(&omap_port->wk_lock); return 0; } - pm_runtime_get_sync(omap_port->pdev); /* Grab clocks */ - writel(SSI_WAKE(0), omap_ssi->sys + SSI_SET_WAKE_REG(port->num)); spin_unlock_bh(&omap_port->wk_lock); + schedule_work(&omap_port->work); + return 0; } @@ -604,9 +614,10 @@ static int ssi_stop_tx(struct hsi_client *cl) return 0; } writel(SSI_WAKE(0), omap_ssi->sys + SSI_CLEAR_WAKE_REG(port->num)); - pm_runtime_put_sync(omap_port->pdev); /* Release clocks */ spin_unlock_bh(&omap_port->wk_lock); + pm_runtime_put(omap_port->pdev); /* Release clocks */ + return 0; } @@ -1149,6 +1160,8 @@ static int ssi_port_probe(struct platform_device *pd) omap_port->pdev = &pd->dev; omap_port->port_id = port_id; + INIT_WORK(&omap_port->work, start_tx_work); + /* initialize HSI port */ port->async = ssi_async; port->setup = ssi_setup;