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=-2.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_NEOMUTT autolearn=ham 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 74429C31E5B for ; Mon, 17 Jun 2019 14:57:29 +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 3C4B22084A for ; Mon, 17 Jun 2019 14:57:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="TRIy7p/E" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3C4B22084A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com 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-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-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=n9NoKqPt0mB7PbGP047d/33tk6j5Re+ZI1cDb6yVl0s=; b=TRIy7p/EHIb/kxIaKiP++QVai tyjCODFHvrXt1i21+0OrAAIRAzcx8KEwY29xdauAoPLg+2QhjUd9uYKXo+Skh75yWGKQUn5AtDb5h kGjEyeRsibUHnExGWtxnvng24zFQJ/jUyP0Bmp74ZexeSuIx5y0g+zsjEpHgzaSZd20xyASRIiNfa DQSgUfHWyWZ1MM7qwGq9y10685lI16FbWd6FUrRgAJu4k0J88b4dx60mfIktJAUFI9E5iJktyGADq rqMNDY55Y7/XUM+Vmj74LGVvPnkgrN3WDBJuUPALxhqqdGpO2K1TtrWa6BcBAnn+eli7pZqSA6pi3 Zcy1vXutQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hct4Y-0001ok-12; Mon, 17 Jun 2019 14:57:26 +0000 Received: from relay10.mail.gandi.net ([217.70.178.230]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hct1g-0006kM-Pi for linux-arm-kernel@lists.infradead.org; Mon, 17 Jun 2019 14:54:30 +0000 Received: from localhost (aaubervilliers-681-1-81-150.w90-88.abo.wanadoo.fr [90.88.23.150]) (Authenticated sender: maxime.ripard@bootlin.com) by relay10.mail.gandi.net (Postfix) with ESMTPSA id C497C240018; Mon, 17 Jun 2019 14:54:20 +0000 (UTC) Date: Mon, 17 Jun 2019 16:54:20 +0200 From: Maxime Ripard To: Chen-Yu Tsai Subject: Re: [linux-sunxi] Re: [PATCH v2 5/9] drm/sun4i: tcon_top: Register clock gates in probe Message-ID: <20190617145420.e7yfrmmhdhift5id@flea> References: <20190614164324.9427-1-jagan@amarulasolutions.com> <20190614164324.9427-6-jagan@amarulasolutions.com> <20190617114503.pclqsf6bo3ih47nt@flea> MIME-Version: 1.0 In-Reply-To: User-Agent: NeoMutt/20180716 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190617_075429_017150_12A77533 X-CRM114-Status: GOOD ( 18.76 ) 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: devicetree , Jernej Skrabec , David Airlie , linux-kernel , dri-devel , linux-sunxi , Jagan Teki , Daniel Vetter , Michael Trimarchi , linux-amarula , linux-arm-kernel Content-Type: multipart/mixed; boundary="===============0909475230184718164==" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org --===============0909475230184718164== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="jzvxnzdlcqa2ksrf" Content-Disposition: inline --jzvxnzdlcqa2ksrf Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Mon, Jun 17, 2019 at 09:01:33PM +0800, Chen-Yu Tsai wrote: > On Mon, Jun 17, 2019 at 7:45 PM Maxime Ripard wrote: > > > > On Fri, Jun 14, 2019 at 10:13:20PM +0530, Jagan Teki wrote: > > > TCON TOP have clock gates for TV0, TV1, dsi and right > > > now these are register during bind call. > > > > > > Of which, dsi clock gate would required during DPHY probe > > > but same can miss to get since tcon top is not bound at > > > that time. > > > > > > To solve, this circular dependency move the clock gate > > > registration from bind to probe so-that DPHY can get the > > > dsi gate clock on time. > > > > It's not really clear to me what the circular dependency is? > > > > if you have a chain that is: > > > > tcon-top +-> DSI > > +-> D-PHY > > > > There's no loop, right? > > Looking at how the DTSI patch structures things (without going into > whether it is correct or accurate): > > The D-PHY is not part of the component graph. However it requests > the DSI gate clock from the TCON-TOP. > > The TCON-TOP driver, in its current form, only registers the clocks > it provides at component bind time. Thus the D-PHY can't successfully > probe until the TCON-TOP has been bound. > > The DSI interface requires the D-PHY to bind. It will return -EPROBE_DEFER > if it cannot request it. This in turn goes into the error path of > component_bind_all, which unbinds all previous components. > > So it's actually > > D-PHY -> TCON-TOP -> DSI > ^ | > |-------------------- > > I've not checked, but I suspect there's no possibility of having other > drivers probe (to deal with deferred probing) within component_bind_all. > Otherwise we shouldn't run into this weird circular dependency issue. > Ah, yes, that makes sense. It should be cleraer in the commit log then. Thanks! Maxime -- Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com --jzvxnzdlcqa2ksrf Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRcEzekXsqa64kGDp7j7w1vZxhRxQUCXQepmwAKCRDj7w1vZxhR xYw9AQDHLFtmVu3MFQ1SBBQaIYnHJKObnT7QFiGqQdKlvtmJPQEAnVAr+0qvuMbJ nxfnMe/iGRf/aI9F/dseertWbl3c1AQ= =Vhms -----END PGP SIGNATURE----- --jzvxnzdlcqa2ksrf-- --===============0909475230184718164== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel --===============0909475230184718164==--