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=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 CF939C433B4 for ; Wed, 28 Apr 2021 16:51:14 +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 72D5561400 for ; Wed, 28 Apr 2021 16:51:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 72D5561400 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.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 836E36EBFE; Wed, 28 Apr 2021 16:51:13 +0000 (UTC) Received: from mail-qv1-xf33.google.com (mail-qv1-xf33.google.com [IPv6:2607:f8b0:4864:20::f33]) by gabe.freedesktop.org (Postfix) with ESMTPS id 010C86EBFE for ; Wed, 28 Apr 2021 16:51:11 +0000 (UTC) Received: by mail-qv1-xf33.google.com with SMTP id a30so4358614qvb.12 for ; Wed, 28 Apr 2021 09:51:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=i7bjsRegze0J8KMBLsd6S1kBXzifIu76DMKQBA84MfE=; b=H6GvR/jJOzxy5yvUfCUkF+EMKldJel4VTzuxpNzjmhRH8YjlZLt2EzcmEoB9kuRTpp J+S1tttlyYfNfXCYv1VnThpaRAKe35vjhUfbxu7lWEsG6xkD6fpttoWrTCDJyaB4s1yh qpsFpp1ULXf6O5GRNrGy8VZodsPVr2ptimptY= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=i7bjsRegze0J8KMBLsd6S1kBXzifIu76DMKQBA84MfE=; b=HIdVZDRUhcF/V77Kq3wmGLMIqNW8ZHv+vGuQH0CMmOD2GOoToV50va6WWr9+JBzZyL 2Qtw2NusW2Z86QtlOunVnTiQR4TvgYCCtsrXEC7Kx/dTisEXxy1ujzJWT1A6yrtn5tjE Qt83p5LIydtnwVsDTtOy8uCVJXgGsMFgfasnWKVgxTSX0jArD0e0bqlXWE51OxA7FHmO c9/Z3+m2vZ7vWSrZSFYUR9CjThxR8NFAbVHYo6hqTadpCh35U5BM3L56Bp11bjN0rKdn mskRGtTbD3vY0PKYVdq+q60YjqeoeiDJucU5d6yRI1zQx2Hjt2Ho9A4iWTDQV4vcQO4F Nwfg== X-Gm-Message-State: AOAM532K9fggw2stWdQnl8tjLVT3m6mdA1HfmX7vwAxDtmUCC3Ii1o2j CBZnT3eKmLx2hNCmsJH0OHG4YsdQl9dk2A== X-Google-Smtp-Source: ABdhPJzDc4ebR4gB07DGfMQgUweJUUJWLfG3TqHClym/ke74IxhohgcVxis1NKz3ZRAel2Adys6dVg== X-Received: by 2002:a05:6214:12d0:: with SMTP id s16mr18035728qvv.60.1619628670838; Wed, 28 Apr 2021 09:51:10 -0700 (PDT) Received: from mail-yb1-f173.google.com (mail-yb1-f173.google.com. [209.85.219.173]) by smtp.gmail.com with ESMTPSA id 198sm208280qkf.20.2021.04.28.09.51.09 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 28 Apr 2021 09:51:10 -0700 (PDT) Received: by mail-yb1-f173.google.com with SMTP id p126so21113712yba.1 for ; Wed, 28 Apr 2021 09:51:09 -0700 (PDT) X-Received: by 2002:a25:778d:: with SMTP id s135mr31447093ybc.21.1619628668908; Wed, 28 Apr 2021 09:51:08 -0700 (PDT) MIME-Version: 1.0 References: <20210423165906.2504169-1-dianders@chromium.org> <20210423095743.v5.18.If050957eaa85cf45b10bcf61e6f7fa61c9750ebf@changeid> In-Reply-To: <20210423095743.v5.18.If050957eaa85cf45b10bcf61e6f7fa61c9750ebf@changeid> From: Sean Paul Date: Wed, 28 Apr 2021 12:50:30 -0400 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v5 18/20] drm/panel: panel-simple: Cache the EDID as long as we retain power To: Douglas Anderson 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: robdclark@chromium.org, Stanislav Lisovskiy , Jernej Skrabec , Jonas Karlman , David Airlie , linux-arm-msm , Neil Armstrong , Linux Kernel Mailing List , dri-devel , Stephen Boyd , Wolfram Sang , Andrzej Hajda , Thierry Reding , Laurent Pinchart , Bjorn Andersson , Sam Ravnborg , Steev Klimaszewski , linux-i2c@vger.kernel.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Fri, Apr 23, 2021 at 1:00 PM Douglas Anderson wrote: > > It doesn't make sense to go out to the bus and read the EDID over and > over again. Let's cache it and throw away the cache when we turn power > off from the panel. Autosuspend means that even if there are several > calls to read the EDID before we officially turn the power on then we > should get good use out of this cache. > I think i915 caches the edid once on init and never refreshes it (assuming no hotplugs). That said, I think it makes sense for a more conservative approach in panel-simple. > Signed-off-by: Douglas Anderson > Reviewed-by: Bjorn Andersson > --- > > (no changes since v1) > > drivers/gpu/drm/panel/panel-simple.c | 17 ++++++++++------- > 1 file changed, 10 insertions(+), 7 deletions(-) > > diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c > index a12dfe8b8d90..9be050ab372f 100644 > --- a/drivers/gpu/drm/panel/panel-simple.c > +++ b/drivers/gpu/drm/panel/panel-simple.c > @@ -189,6 +189,8 @@ struct panel_simple { > struct gpio_desc *enable_gpio; > struct gpio_desc *hpd_gpio; > > + struct edid *edid; > + > struct drm_display_mode override_mode; > > enum drm_panel_orientation orientation; > @@ -345,6 +347,9 @@ static int panel_simple_suspend(struct device *dev) > regulator_disable(p->supply); > p->unprepared_time = ktime_get(); > > + kfree(p->edid); > + p->edid = NULL; > + > return 0; > } > > @@ -510,15 +515,13 @@ static int panel_simple_get_modes(struct drm_panel *panel, > > /* probe EDID if a DDC bus is available */ > if (p->ddc) { > - struct edid *edid; > - > pm_runtime_get_sync(panel->dev); > > - edid = drm_get_edid(connector, p->ddc); > - if (edid) { > - num += drm_add_edid_modes(connector, edid); > - kfree(edid); > - } > + if (!p->edid) > + p->edid = drm_get_edid(connector, p->ddc); > + > + if (p->edid) > + num += drm_add_edid_modes(connector, p->edid); I suppose this would keep banging on the ddc if drm_get_edid() continuously returns NULL, but maybe that's desireable (it'll succeed sometime in the future)? At any rate, this is an improvement on current behavior so it has my vote. Reviewed-by: Sean Paul > > pm_runtime_mark_last_busy(panel->dev); > pm_runtime_put_autosuspend(panel->dev); > -- > 2.31.1.498.g6c1eba8ee3d-goog > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel