From mboxrd@z Thu Jan 1 00:00:00 1970 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 D1830C433F5 for ; Sat, 12 Mar 2022 18:51:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231589AbiCLSwJ (ORCPT ); Sat, 12 Mar 2022 13:52:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56342 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230452AbiCLSwG (ORCPT ); Sat, 12 Mar 2022 13:52:06 -0500 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2A5A414076D for ; Sat, 12 Mar 2022 10:50:59 -0800 (PST) Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id CD5CB183C; Sat, 12 Mar 2022 19:50:57 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1647111058; bh=AKx3scubGuB11zo319vCyuxVmBrzwLvbWOULCTJFKCc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=niFu+wlqxLmpCM/tApZpuvTbSxf0YzxfajjHPnPvGYAHe72i3BZugMSO8qbqer8RS LZVTuNyaxXtx28NnzZFp6HEKDJFmOfDzynQgqCcCO+xkkuNUU+E8QZ8wawgB6nnjrP kck0Z0xZ3VErLXOAXg2d0WhgZUn6yDcfPkZLc2H0= Date: Sat, 12 Mar 2022 20:50:40 +0200 From: Laurent Pinchart To: Jacopo Mondi Cc: linux-media@vger.kernel.org, Rui Miguel Silva , kernel@pengutronix.de, linux-imx@nxp.com, Paul Elder , Sakari Ailus Subject: Re: [PATCH 2/2] media: imx: imx-mipi-csis: Drop powered flag Message-ID: References: <20220311135535.30108-1-laurent.pinchart@ideasonboard.com> <20220312152505.145453-2-jacopo@jmondi.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20220312152505.145453-2-jacopo@jmondi.org> Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Hi Jacopo, Thank you for the patch. On Sat, Mar 12, 2022 at 04:25:05PM +0100, Jacopo Mondi wrote: > The mipi_csis_device.powered flag only serves for the purpose of > not accessing registers in mipi_csis_log_status() when the interface > is not powered up. > > Instead of manually tracking the power state, rely on > pm_runtime_get_if_in_use() and remove the flag. > > Signed-off-by: Jacopo Mondi > --- > drivers/media/platform/imx/imx-mipi-csis.c | 18 ++++++++++-------- > 1 file changed, 10 insertions(+), 8 deletions(-) > > diff --git a/drivers/media/platform/imx/imx-mipi-csis.c b/drivers/media/platform/imx/imx-mipi-csis.c > index fa00b36fc394..505dd373b40c 100644 > --- a/drivers/media/platform/imx/imx-mipi-csis.c > +++ b/drivers/media/platform/imx/imx-mipi-csis.c > @@ -327,10 +327,9 @@ struct mipi_csis_device { > u32 hs_settle; > u32 clk_settle; > > - struct mutex lock; /* Protect csis_fmt, format_mbus and powered */ > + struct mutex lock; /* Protect csis_fmt and format_mbus */ > const struct csis_pix_format *csis_fmt; > struct v4l2_mbus_framefmt format_mbus[CSIS_PADS_NUM]; > - bool powered; > > spinlock_t slock; /* Protect events */ > struct mipi_csis_event events[MIPI_CSIS_NUM_EVENTS]; > @@ -1176,8 +1175,15 @@ static int mipi_csis_log_status(struct v4l2_subdev *sd) > > mutex_lock(&csis->lock); > mipi_csis_log_counters(csis, true); > - if (csis->debug.enable && csis->powered) > - mipi_csis_dump_regs(csis); > + if (!csis->debug.enable || > + !pm_runtime_get_if_in_use(csis->dev)) > + goto unlock; > + > + mipi_csis_dump_regs(csis); > + > + pm_runtime_put(csis->dev); > + > +unlock: I like this change, but I think we can go one step further and drop the lock here, as there's no powered field to access anymore: struct mipi_csis_device *csis = sd_to_mipi_csis_device(sd); mipi_csis_log_counters(csis, true); if (csis->debug.enable && pm_runtime_get_if_in_use(csi->dev)) { mipi_csis_dump_regs(csis); pm_runtime_put(csis->dev); } return 0; A third patch could then drop the lock from mipi_csis_runtime_suspend() and mipi_csis_runtime_resume(). What do you think ? > mutex_unlock(&csis->lock); > > return 0; > @@ -1344,8 +1350,6 @@ static int __maybe_unused mipi_csis_runtime_suspend(struct device *dev) > > mipi_csis_clk_disable(csis); > > - csis->powered = false; > - > unlock: > mutex_unlock(&csis->lock); > > @@ -1366,8 +1370,6 @@ static int __maybe_unused mipi_csis_runtime_resume(struct device *dev) > > mipi_csis_clk_enable(csis); > > - csis->powered = true; > - > unlock: > mutex_unlock(&csis->lock); > -- Regards, Laurent Pinchart