From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757301AbdELKuP (ORCPT ); Fri, 12 May 2017 06:50:15 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:48642 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751323AbdELKuN (ORCPT ); Fri, 12 May 2017 06:50:13 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 93FF760A00 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=architt@codeaurora.org Subject: Re: [PATCH v2 6/8] drm: Introduce drm_bridge_mode_valid() To: Laurent Pinchart , dri-devel@lists.freedesktop.org References: <20170510134109.GF12629@intel.com> <20170510151433.7ewizmeeidrqonan@phenom.ffwll.local> <1645078.FS6fmucJTb@avalon> Cc: Jose Abreu , Daniel Vetter , Alexey Brodkin , linux-kernel@vger.kernel.org, Carlos Palminha From: Archit Taneja Message-ID: Date: Fri, 12 May 2017 16:20:07 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.7.0 MIME-Version: 1.0 In-Reply-To: <1645078.FS6fmucJTb@avalon> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/12/2017 03:08 PM, Laurent Pinchart wrote: > Hi Daniel, > > On Wednesday 10 May 2017 17:14:33 Daniel Vetter wrote: >> On Wed, May 10, 2017 at 04:41:09PM +0300, Ville Syrjälä wrote: >>> On Tue, May 09, 2017 at 06:00:13PM +0100, Jose Abreu wrote: >>>> Introduce a new helper function which calls mode_valid() callback >>>> for all bridges in an encoder chain. >>>> >>>> Signed-off-by: Jose Abreu >>>> Cc: Carlos Palminha >>>> Cc: Alexey Brodkin >>>> Cc: Ville Syrjälä >>>> Cc: Daniel Vetter >>>> Cc: Dave Airlie >>>> Cc: Andrzej Hajda >>>> Cc: Archit Taneja >>>> --- >>>> >>>> drivers/gpu/drm/drm_bridge.c | 33 +++++++++++++++++++++++++++++++++ >>>> include/drm/drm_bridge.h | 2 ++ >>>> 2 files changed, 35 insertions(+) >>>> >>>> diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c >>>> index 86a7637..dc8cdfe 100644 >>>> --- a/drivers/gpu/drm/drm_bridge.c >>>> +++ b/drivers/gpu/drm/drm_bridge.c >>>> @@ -206,6 +206,39 @@ bool drm_bridge_mode_fixup(struct drm_bridge >>>> *bridge, >>>> >>>> EXPORT_SYMBOL(drm_bridge_mode_fixup); >>>> >>>> /** >>>> >>>> + * drm_bridge_mode_valid - validate the mode against all bridges in the >>>> + * encoder chain. >>>> + * @bridge: bridge control structure >>>> + * @mode: desired mode to be validated >>>> + * >>>> + * Calls &drm_bridge_funcs.mode_valid for all the bridges in the >>>> encoder >>>> + * chain, starting from the first bridge to the last. If at least one >>>> bridge + * does not accept the mode the function returns the error >>>> code. >>>> + * >>>> + * Note: the bridge passed should be the one closest to the encoder. >>>> + * >>>> + * RETURNS: >>>> + * MODE_OK on success, drm_mode_status Enum error code on failure >>>> + */ >>>> +enum drm_mode_status drm_bridge_mode_valid(struct drm_bridge *bridge, >>>> + const struct drm_display_mode > *mode) >>>> +{ >>>> + enum drm_mode_status ret = MODE_OK; >>>> + >>>> + if (!bridge) >>>> + return ret; >>>> + >>>> + if (bridge->funcs->mode_valid) >>>> + ret = bridge->funcs->mode_valid(bridge, mode); >>>> + >>>> + if (ret != MODE_OK) >>>> + return ret; >>>> + >>>> + return drm_bridge_mode_valid(bridge->next, mode); >>> >>> Looks like it should be pretty trivial to avoid the recursion. >>> >>> Am I correct in interpreting this that bridges have some kind of >>> a hand rolled linked list implementation? Reusing the standard >>> linked lists would allow you to use list_for_each() etc. >> >> Yeah it's a hand-rolled list, but current hw also has a bridge nesting >> depth of 2, so it really doesn't matter. I guess once we have real long >> chains of bridges we can fix this (and just using list_head sounds like a >> great idea). > > Even if not really needed right now, it's a pretty easy cleanup, if Jose has > time to handle it in v3 of this series let's not postpone it ;-) jfyi, some of the bridge functions call the ops from the last bridge in the chain to first, so we'd need to use list_for_each_entry_prev() (or something like that) for them. Archit -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project