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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 3217CC433E0 for ; Mon, 8 Mar 2021 20:44:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F338564DF5 for ; Mon, 8 Mar 2021 20:44:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231265AbhCHUn6 (ORCPT ); Mon, 8 Mar 2021 15:43:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54070 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229471AbhCHUn0 (ORCPT ); Mon, 8 Mar 2021 15:43:26 -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 56736C06174A; Mon, 8 Mar 2021 12:43:26 -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 75B23E7B; Mon, 8 Mar 2021 21:43:24 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1615236204; bh=eUIxsi6KUQOw5q47XWeSrdAkbyfhRraA71IbHa9KDhY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=lJhlDVqUrAmPMxbo24TtmerInhAUXJLZaYnFraZ2XCkmvBAJATYIs9i1t1BE9Lk0k fb9L467HOf4vTHEbdlOR5LnBULflEuzWb+cU5MsFGvJI/kbFsptv1cpB+cHK4ddugF H2Sb8UI3Q2n057EJoJi1R2O9WUnyXMi/uzLNxvFE= Date: Mon, 8 Mar 2021 22:42:53 +0200 From: Laurent Pinchart To: Parshuram Raju Thombare Cc: "robert.foss@linaro.org" , "robh+dt@kernel.org" , "airlied@linux.ie" , "daniel@ffwll.ch" , "dri-devel@lists.freedesktop.org" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "a.hajda@samsung.com" , "narmstrong@baylibre.com" , "nikhil.nd@ti.com" , "kishon@ti.com" , Swapnil Kashinath Jakhade , Milind Parab Subject: Re: [PATCH v2 1/2] dt-bindings: drm/bridge: MHDP8546 bridge binding changes for HDCP Message-ID: References: <1614597685-4192-1-git-send-email-pthombar@cadence.com> <1614597746-4563-1-git-send-email-pthombar@cadence.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Parshuram, On Tue, Mar 02, 2021 at 12:53:50PM +0000, Parshuram Raju Thombare wrote: > Hi Laurent, > > >>> Is this a property of the hardware, that is, are there multiple versions > >>> of this IP core covered by the same compatible string that support HDCP > >>> 1.4 only, DHCP 2.2 only or both ? Or is it a way to select what a given > >>> system will offer ?[] > >> > >> MHDP hardware supports both HDCP 2.2 and 1.4. So, this is a way > >> to select the version of HDCP, system wish to support. > > > > Then I'm not sure this qualifies as a DT property, which should describe > > the system, not configure it. A way for userspace to configure this > > would be better. > > Since this is for source device, I am not sure how useful it is to allow > user to change HDCP version supported. I think doing it in DTS > gives more control over HDCP to system designer/integrator. But how would they do so ? What would be the rationale for selecting a particular version in DT ? I'm not thinking about giving control of this parameter to the end-user, but in the context of an embedded system, it may be useful to select which HDCP versions to offer based on different constraints at runtime. This really seems like a system configuration parameter to me, not a system description. -- Regards, Laurent Pinchart 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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 7879AC433DB for ; Mon, 8 Mar 2021 20:43:28 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 2C57A64F09 for ; Mon, 8 Mar 2021 20:43:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2C57A64F09 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ideasonboard.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id AC6706E3D2; Mon, 8 Mar 2021 20:43:27 +0000 (UTC) Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by gabe.freedesktop.org (Postfix) with ESMTPS id E68176E3D2 for ; Mon, 8 Mar 2021 20:43:26 +0000 (UTC) Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 75B23E7B; Mon, 8 Mar 2021 21:43:24 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1615236204; bh=eUIxsi6KUQOw5q47XWeSrdAkbyfhRraA71IbHa9KDhY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=lJhlDVqUrAmPMxbo24TtmerInhAUXJLZaYnFraZ2XCkmvBAJATYIs9i1t1BE9Lk0k fb9L467HOf4vTHEbdlOR5LnBULflEuzWb+cU5MsFGvJI/kbFsptv1cpB+cHK4ddugF H2Sb8UI3Q2n057EJoJi1R2O9WUnyXMi/uzLNxvFE= Date: Mon, 8 Mar 2021 22:42:53 +0200 From: Laurent Pinchart To: Parshuram Raju Thombare Subject: Re: [PATCH v2 1/2] dt-bindings: drm/bridge: MHDP8546 bridge binding changes for HDCP Message-ID: References: <1614597685-4192-1-git-send-email-pthombar@cadence.com> <1614597746-4563-1-git-send-email-pthombar@cadence.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "devicetree@vger.kernel.org" , "narmstrong@baylibre.com" , "airlied@linux.ie" , "linux-kernel@vger.kernel.org" , "dri-devel@lists.freedesktop.org" , "kishon@ti.com" , "a.hajda@samsung.com" , "robh+dt@kernel.org" , "robert.foss@linaro.org" , Swapnil Kashinath Jakhade , "nikhil.nd@ti.com" , Milind Parab Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Hi Parshuram, On Tue, Mar 02, 2021 at 12:53:50PM +0000, Parshuram Raju Thombare wrote: > Hi Laurent, > > >>> Is this a property of the hardware, that is, are there multiple versions > >>> of this IP core covered by the same compatible string that support HDCP > >>> 1.4 only, DHCP 2.2 only or both ? Or is it a way to select what a given > >>> system will offer ?[] > >> > >> MHDP hardware supports both HDCP 2.2 and 1.4. So, this is a way > >> to select the version of HDCP, system wish to support. > > > > Then I'm not sure this qualifies as a DT property, which should describe > > the system, not configure it. A way for userspace to configure this > > would be better. > > Since this is for source device, I am not sure how useful it is to allow > user to change HDCP version supported. I think doing it in DTS > gives more control over HDCP to system designer/integrator. But how would they do so ? What would be the rationale for selecting a particular version in DT ? I'm not thinking about giving control of this parameter to the end-user, but in the context of an embedded system, it may be useful to select which HDCP versions to offer based on different constraints at runtime. This really seems like a system configuration parameter to me, not a system description. -- Regards, Laurent Pinchart _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel