From patchwork Mon Feb 26 07:28:05 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marek Vasut X-Patchwork-Id: 13571368 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 17A57C5478C for ; Mon, 26 Feb 2024 07:29:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:Cc :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=KWKVYOGfqjUKKCnm4yux+atjMBLGu3jBKTyTpC3MBkU=; b=HxI3HriyFc81zO VBH/B6OP8kcnUSisZpIw5+ZB82o2OHN8qmFQpDodMI8ABGqYd5udFOy+ZXMjJliEFvZN+WWRyWcgH Zs/OY/Cmr7T+SP8f0R7NYe5iFmIzIkrY5Sq9UsJac92z2lzF4iVacIVdVOSBFPu7Y82c4REh0Eg4/ 2uSwusyvVEOJAl7R1ysJUSLBrdDt3/YNIHqgWMjsUqJ3UGs2XQ+Umz7ScdxITbho2eBVk2MtaDLau oSVI/Do0DeD8hCgIm99vSAeoSG86dpdIB2/dGMvKCg41LwnNsEUoR0tjnPMIfTgcMLUTvD8mijp1e hUmCf0K5MkUfZ7UT06dA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1reVQR-0000000Gmd3-03dG; Mon, 26 Feb 2024 07:29:23 +0000 Received: from phobos.denx.de ([85.214.62.61]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1reVQN-0000000Gmbd-4B0b for linux-arm-kernel@lists.infradead.org; Mon, 26 Feb 2024 07:29:21 +0000 Received: from tr.lan (ip-86-49-120-218.bb.vodafone.cz [86.49.120.218]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: marex@denx.de) by phobos.denx.de (Postfix) with ESMTPSA id 76B7087E57; Mon, 26 Feb 2024 08:29:15 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1708932556; bh=Q5um3ivLQj7jnQAlIm7t/S13QiY81Td25KKqrzzD6dU=; h=From:To:Cc:Subject:Date:From; b=LSAyPjU7eWMBjFZQU+hCdwI0Gwhatpd+t8rRoYl4ECLnK/teEvdLx582EIHgEKm+m rG7a93pdXm598SS+xyGZLBGeMKBNyWj+yJNcaArx9e9XFrvXY0mrzjrjzzjd/77xgT OosvErfmql3iPr+ICfhE489fTDD2IBiDMpUpiIa8W1biislA2ybw9Z+I182sSKpcCq aFOAxJ7ng/ysn22LVwgIwl5CQZ2HzwuKiMpuvNOqeBID4yhygJ9EB0ElT/9WijJAuL ApYbNdidqYGvV+Hc1IQ7tcUgqFIzpRnuKgmCpQ427oe/IUp3mmBhRJo6DjtlDPkesL E5j9pYOpJfDYg== From: Marek Vasut To: dri-devel@lists.freedesktop.org Cc: Marek Vasut , Liu Ying , Daniel Vetter , David Airlie , Fabio Estevam , Maarten Lankhorst , Maxime Ripard , NXP Linux Team , Pengutronix Kernel Team , Sascha Hauer , Shawn Guo , Stefan Agner , Thomas Zimmermann , linux-arm-kernel@lists.infradead.org Subject: [PATCH v2] drm/lcdif: Do not disable clocks on already suspended hardware Date: Mon, 26 Feb 2024 08:28:05 +0100 Message-ID: <20240226072904.26861-1-marex@denx.de> X-Mailer: git-send-email 2.43.0 MIME-Version: 1.0 X-Virus-Scanned: clamav-milter 0.103.8 at phobos.denx.de X-Virus-Status: Clean X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240225_232920_357442_339F92CE X-CRM114-Status: GOOD ( 17.38 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org In case the LCDIF is enabled in DT but unused, the clocks used by the LCDIF are not enabled. Those clocks may even have a use count of 0 in case there are no other users of those clocks. This can happen e.g. in case the LCDIF drives HDMI bridge which has no panel plugged into the HDMI connector. Do not attempt to disable clocks in the suspend callback and re-enable clocks in the resume callback unless the LCDIF is enabled and was in use before the system entered suspend, otherwise the driver might end up trying to disable clocks which are already disabled with use count 0, and would trigger a warning from clocks core about this condition. Note that the lcdif_rpm_suspend() and lcdif_rpm_resume() functions internally perform the clocks disable and enable operations and act as runtime PM hooks too. Reviewed-by: Liu Ying Fixes: 9db35bb349a0 ("drm: lcdif: Add support for i.MX8MP LCDIF variant") Signed-off-by: Marek Vasut --- Cc: Daniel Vetter Cc: David Airlie Cc: Fabio Estevam Cc: Liu Ying Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: NXP Linux Team Cc: Pengutronix Kernel Team Cc: Sascha Hauer Cc: Shawn Guo Cc: Stefan Agner Cc: Thomas Zimmermann Cc: dri-devel@lists.freedesktop.org Cc: linux-arm-kernel@lists.infradead.org --- V2: - s@clock@clocks@g in commit message - Add RB from Liu --- drivers/gpu/drm/mxsfb/lcdif_drv.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/mxsfb/lcdif_drv.c b/drivers/gpu/drm/mxsfb/lcdif_drv.c index 18de2f17e2491..6494e82707569 100644 --- a/drivers/gpu/drm/mxsfb/lcdif_drv.c +++ b/drivers/gpu/drm/mxsfb/lcdif_drv.c @@ -340,6 +340,9 @@ static int __maybe_unused lcdif_suspend(struct device *dev) if (ret) return ret; + if (pm_runtime_suspended(dev)) + return 0; + return lcdif_rpm_suspend(dev); } @@ -347,7 +350,8 @@ static int __maybe_unused lcdif_resume(struct device *dev) { struct drm_device *drm = dev_get_drvdata(dev); - lcdif_rpm_resume(dev); + if (!pm_runtime_suspended(dev)) + lcdif_rpm_resume(dev); return drm_mode_config_helper_resume(drm); }