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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 3988EC433ED for ; Wed, 14 Apr 2021 17:55:19 +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 ED1BC61242 for ; Wed, 14 Apr 2021 17:55:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ED1BC61242 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codeaurora.org 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 3320589BF8; Wed, 14 Apr 2021 17:55:18 +0000 (UTC) Received: from so254-9.mailgun.net (so254-9.mailgun.net [198.61.254.9]) by gabe.freedesktop.org (Postfix) with ESMTPS id 0495F89BF8 for ; Wed, 14 Apr 2021 17:55:15 +0000 (UTC) DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1618422916; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=3uShNxK5FJYLasDW+nrg03JrG9d+DonaEeEOaVhcnHk=; b=aIGYwUrSOsg3xM0j5kTcfpNwBQNGCFSGD2aYnS5TjDFDmIvQNaLvQOzjocS7A1B2H/L0S2X/ lXqiiPvjsPnIu1gi5eudsTQtk6bEmxuZ9Fe4nnFh0sRcnmqMyGiufcxfn5lQWAURaZhSl+D2 cSDvQ1+ApvVVWy2AwddlGXOw9ZM= X-Mailgun-Sending-Ip: 198.61.254.9 X-Mailgun-Sid: WyJkOTU5ZSIsICJkcmktZGV2ZWxAbGlzdHMuZnJlZWRlc2t0b3Aub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n03.prod.us-east-1.postgun.com with SMTP id 60772c7f03cfff3452b380a1 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Wed, 14 Apr 2021 17:55:11 GMT Received: by smtp.codeaurora.org (Postfix, from userid 1001) id C876FC43463; Wed, 14 Apr 2021 17:55:10 +0000 (UTC) Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: khsieh) by smtp.codeaurora.org (Postfix) with ESMTPSA id CE1CCC433CA; Wed, 14 Apr 2021 17:55:09 +0000 (UTC) MIME-Version: 1.0 Date: Wed, 14 Apr 2021 10:55:09 -0700 From: khsieh@codeaurora.org To: Stephen Boyd Subject: Re: [PATCH v2 2/3] drm/msm/dp: do not re initialize of audio_comp at display_disable() In-Reply-To: <161837022104.3764895.807226402876043006@swboyd.mtv.corp.google.com> References: <1618355490-5292-1-git-send-email-khsieh@codeaurora.org> <161837022104.3764895.807226402876043006@swboyd.mtv.corp.google.com> Message-ID: X-Sender: khsieh@codeaurora.org User-Agent: Roundcube Webmail/1.3.9 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: freedreno@lists.freedesktop.org, airlied@linux.ie, linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, abhinavk@codeaurora.org, tanmay@codeaurora.org, aravindh@codeaurora.org, sean@poorly.run Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On 2021-04-13 20:17, Stephen Boyd wrote: > Quoting Kuogee Hsieh (2021-04-13 16:11:30) >> At dongle unplug, dp initializes audio_comp followed by sending >> disconnect >> event notification to audio and to make sure audio had shutdown >> completely >> by wait for audio completion notification at display_disable(). This >> patch > > Is this dp_display_disable()? Doubtful that display_disable() is the > function we're talking about. yes > >> will not re initialize audio_comp at display_disable() if audio >> shutdown >> is triggered by dongle unplugged. > > This commit text seems to say the why before the what, where why is "dp > initializes audio_comp followed by sending disconnect.." and the what > is > "this patch will no re-initialized audio_comp...". Can you reorder this > so the what comes before the why? > ok >> >> Signed-off-by: Kuogee Hsieh >> --- >> drivers/gpu/drm/msm/dp/dp_display.c | 6 ++++-- >> 1 file changed, 4 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c >> b/drivers/gpu/drm/msm/dp/dp_display.c >> index 0ba71c7..1d71c95 100644 >> --- a/drivers/gpu/drm/msm/dp/dp_display.c >> +++ b/drivers/gpu/drm/msm/dp/dp_display.c >> @@ -894,8 +894,10 @@ static int dp_display_disable(struct >> dp_display_private *dp, u32 data) >> /* wait only if audio was enabled */ >> if (dp_display->audio_enabled) { >> /* signal the disconnect event */ >> - reinit_completion(&dp->audio_comp); >> - dp_display_handle_plugged_change(dp_display, false); >> + if (dp->hpd_state != ST_DISCONNECT_PENDING) { >> + reinit_completion(&dp->audio_comp); > > Why is this reinitialized here at all? Wouldn't it make more sense to > initialize the completion once at cable plug in and then not initialize > the completion anywhere else? Or initialize the completion whenever > dp_display->audio_enabled is set to true and then only wait for the > completion here if that boolean is true? Or initialize the completion > when dp_display_handle_plugged_change() is passed true for the > 'plugged' > argument? > yes, i think it is better approach, this will take care of both unplug > and suspend. > I started reading the code and quickly got lost figuring out how > dp_display_handle_plugged_change() worked and the interaction between > the dp display code and the audio codec embedded in here. There seem to > be a couple of conditions that cut off things early, like > dp_display->audio_enabled and audio->engine_on. Why? Why does > dp_display_signal_audio_complete() call complete_all() vs. just > complete()? Please help! :( > >> + dp_display_handle_plugged_change(dp_display, >> false); > > I think it's this way because dp_hpd_unplug_handle() is the function > that sets the hpd_state to ST_DISCONNECT_PENDING and then reinitializes > the completion (why?) and calls dp_display_handle_plugged_change(). So > the commit text could say that reinitializing the completion again here > at dp_display_disable() is racing with the audio code in the case that > dp_hpd_unplug_handle() already called > dp_display_handle_plugged_change() and it would make more sense. But > the > question still stands why that race even exists in the first place vs. > initializing the completion variable in only one place unconditionally > when the cable is connected, in dp_hpd_plug_handle() or > dp_display_post_enable(). > >> + } >> if (!wait_for_completion_timeout(&dp->audio_comp, >> HZ * 5)) >> DRM_ERROR("audio comp timeout\n"); _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel