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 X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4D666C1975A for ; Thu, 12 Mar 2020 13:29:55 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 01080206E7 for ; Thu, 12 Mar 2020 13:29:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="N0vxITa0" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 01080206E7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=uqaLOV402C+6YKUwOSdh7U0k4cu42294t8xe7zclJPI=; b=N0vxITa008sa44 L12lijsRgMB8bPnfYXzzervd0Z7y1ht+wJ1Z5cvJ3QyQ038WginLKVVO95jqk5W1fJm5aMdiWzlae Ge7+HxycdsgE6IEqXeqCedpIzrb3MF9jLta0c4EDQQ4PuO9OhHkIQWwaYG5ejMuNhqYD1Pz5vQ5Ml oLHRNsngm+g0NR/wnKm1xtcqUGlodlI4WiekqshkaEFXRM/bIQCOPThcQeMV/u++JpQwGZxgu/2rq eTcI8PVL/Hke/w5FIj02SndVEIZoX3Eqel0Ku13CBDgUhfNpRFU/5KgebEz8/9Q6/bwsD4Jr1BHx+ 996CJC/dvClP5GIcbqVA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jCNuM-0001lu-KP; Thu, 12 Mar 2020 13:29:54 +0000 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jCNuJ-0001l7-E8 for linux-arm-kernel@lists.infradead.org; Thu, 12 Mar 2020 13:29:53 +0000 Received: from pty.hi.pengutronix.de ([2001:67c:670:100:1d::c5]) by metis.ext.pengutronix.de with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jCNuC-0007Km-DG; Thu, 12 Mar 2020 14:29:44 +0100 Received: from ukl by pty.hi.pengutronix.de with local (Exim 4.89) (envelope-from ) id 1jCNuA-0001ji-U0; Thu, 12 Mar 2020 14:29:42 +0100 Date: Thu, 12 Mar 2020 14:29:42 +0100 From: Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= To: Pascal Roeleven Subject: Re: pwm: sun4i: pwm-backlight not working since 5.6-rc1 Message-ID: <20200312132942.2kfspvmoc3mxkdx4@pengutronix.de> References: <6185b5540ca082d887d7d13330c9d938@pascalroeleven.nl> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <6185b5540ca082d887d7d13330c9d938@pascalroeleven.nl> User-Agent: NeoMutt/20170113 (1.7.2) X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c5 X-SA-Exim-Mail-From: ukl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-arm-kernel@lists.infradead.org X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200312_062951_477144_64F6D46C X-CRM114-Status: GOOD ( 15.02 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pwm@vger.kernel.org, linux-sunxi@googlegroups.com, linux-kernel@vger.kernel.org, Maxime Ripard , Chen-Yu Tsai , Thierry Reding , Philipp Zabel , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Mar 12, 2020 at 01:22:13PM +0100, Pascal Roeleven wrote: > Hi all, > = > I am working on adding an old A10 device to mainline and noticed an issue > when testing on 5.5.8 vs master. > = > Since 5.6-rc1, I can't control the brightness of my LCD backlight anymore. > The backlight stays on full brightness instead. I am controlling the > brightness value via sysfs for testing. > = > I am not sure if this is a general pwm-sun4i issue or if it is related to > the backlight. However I narrowed it down to one commit for pwm-sun4i: > = > fa4d81784681a26bcf7d2a43c6ac5cf991ef28f5 > = > If I use pwm-sun4i.c from 5b090b430d750961305030232314b6acdb0102aa on > master, the backlight works fine. Unfortunately, due to my lack of kernel > experience, I can't see how the commit above broke it. Hmm, I cannot see how fa4d81784681a26bcf7d2a43c6ac5cf991ef28f5 breaks this. Looking at the output of git show -b fa4d81784681a26bcf7d2a43c6ac5cf991ef28f5 (i.e. ignoring whitespace changes) I don't see how the behaviour you're reporting can be explained. Are you sure that fa4d81784681a26bcf7d2a43c6ac5cf991ef28f5 is the bad commit? Can you install a tool to inspect register values and check how the affected registers change if you switch kernel versions and/or pwm settings? (e.g. memtool md 0x1c20e00+0xc ) Best regards Uwe -- = Pengutronix e.K. | Uwe Kleine-K=F6nig | Industrial Linux Solutions | https://www.pengutronix.de/ | _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel