Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932412AbbERQdj (ORCPT ); Mon, 18 May 2015 12:33:39 -0400 Received: from mail.kmu-office.ch ([178.209.48.109]:58291 "EHLO mail.kmu-office.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932306AbbERQde (ORCPT ); Mon, 18 May 2015 12:33:34 -0400 From: Stefan Agner To: wg@grandegger.com, mkl@pengutronix.de Cc: chripell@fsfe.org, linux-can@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, stefan@agner.ch Subject: [PATCH 1/2] can: mcp251x: fix resume when device is down Date: Mon, 18 May 2015 18:33:27 +0200 Message-Id: <1431966808-26213-1-git-send-email-stefan@agner.ch> X-Mailer: git-send-email 2.4.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2007 Lines: 54 If a valid power regulator or a dummy regulator is used (which happens to be the case when no regulator is specified), restart_work is queued no matter whether the device was running or not at suspend time. Since work queues get initialized in the ndo_open callback, resuming leads to a NULL pointer exception. Reverse exactly the steps executed at suspend time: - Enable the power regulator in any case - Enable the transceiver regulator if the device was running, even in case we have a power regulator - Queue restart_work only in case the device was running Fixes: bf66f3736a94 ("can: mcp251x: Move to threaded interrupts instead of workqueues.") Signed-off-by: Stefan Agner --- drivers/net/can/spi/mcp251x.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c index bf63fee..34c625e 100644 --- a/drivers/net/can/spi/mcp251x.c +++ b/drivers/net/can/spi/mcp251x.c @@ -1221,17 +1221,16 @@ static int __maybe_unused mcp251x_can_resume(struct device *dev) struct spi_device *spi = to_spi_device(dev); struct mcp251x_priv *priv = spi_get_drvdata(spi); - if (priv->after_suspend & AFTER_SUSPEND_POWER) { + if (priv->after_suspend & AFTER_SUSPEND_POWER) mcp251x_power_enable(priv->power, 1); + + if (priv->after_suspend & AFTER_SUSPEND_UP) { + mcp251x_power_enable(priv->transceiver, 1); queue_work(priv->wq, &priv->restart_work); } else { - if (priv->after_suspend & AFTER_SUSPEND_UP) { - mcp251x_power_enable(priv->transceiver, 1); - queue_work(priv->wq, &priv->restart_work); - } else { - priv->after_suspend = 0; - } + priv->after_suspend = 0; } + priv->force_quit = 0; enable_irq(spi->irq); return 0; -- 2.4.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/