From patchwork Mon Apr 18 16:56:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 12816956 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 6BF5DC433EF for ; Mon, 18 Apr 2022 16:58:42 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id BE72D10E2A8; Mon, 18 Apr 2022 16:58:38 +0000 (UTC) Received: from mail-pj1-x1034.google.com (mail-pj1-x1034.google.com [IPv6:2607:f8b0:4864:20::1034]) by gabe.freedesktop.org (Postfix) with ESMTPS id 096C210E17B for ; Mon, 18 Apr 2022 16:58:37 +0000 (UTC) Received: by mail-pj1-x1034.google.com with SMTP id 2so13468903pjw.2 for ; Mon, 18 Apr 2022 09:58:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=CC9jkjjrl6o9e+m2QrQyEFgI0n/S9yVQ8H3riU8oA9o=; b=Iau0mJqjglK3h0t7SvYSqp8QbKm1ztccvyDYYCkGRp1Gg2143E8UHix/S4JXpHIWoG aq5ZJOv2CUXljCg0Mkrv4S83zRDopc5d90yk1EeUX/wPSZcF54Sm3l1RQCKgEgT/F736 gxq+Why9Hajy2zn0MMbZMdqabTgKFyIcCKsXI= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=CC9jkjjrl6o9e+m2QrQyEFgI0n/S9yVQ8H3riU8oA9o=; b=XDEto8l9yM2FsCnDJYp3s/VO2NLfc4+1caX+JUXI0kvdSbLxC2QP/Ohqy7kXSRyuTY 7aToQ9pR8xGsiLF+dR1rYb6LSj+IgquNK3RIjtWB7GGuasrJ5FGIM+QML87dF9kzzoaU 7eTgDzxErKOOeWIc4getVlxPdIWlkiGmRv4jDLkvQ3yxUk3TPPmeBF0BNcu3KYQLXKnj nQkCAZCYcQM7ZZYeHRilJyZDowLhngwOiJEKi7PMhoglzk4qd/pPZd6heer00pl520Fb PSzqRhBhN4fEfFPkSBNTL3i6v+cyGVX17vsn0erEes0f1xnIXnt/KEk0cGjDA0wM1vvW L6Kw== X-Gm-Message-State: AOAM532eDvHaKIVonkzugUd+TR/bdvichWdPunvK+v/qF+0Rd6wScu43 xaAoT3yNLgyi9ZeURDskNfevkHWXQD4Elljs X-Google-Smtp-Source: ABdhPJxMrpFLO1E/CkQC+viUKJbZKgLwOm1B4sMWpkvC80G70lohY/cBOdd8j8PgCo/0uJ7i+KBbvQ== X-Received: by 2002:a17:90b:4d0a:b0:1d1:7bd:cb00 with SMTP id mw10-20020a17090b4d0a00b001d107bdcb00mr17354367pjb.242.1650301116542; Mon, 18 Apr 2022 09:58:36 -0700 (PDT) Received: from tictac2.mtv.corp.google.com ([2620:15c:202:201:94f4:f90:c59f:129b]) by smtp.gmail.com with ESMTPSA id l8-20020a17090a150800b001cbaf536a3esm17700980pja.18.2022.04.18.09.58.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 18 Apr 2022 09:58:35 -0700 (PDT) From: Douglas Anderson To: dri-devel@lists.freedesktop.org Subject: [PATCH v2 2/4] drm/panel-edp: Take advantage of wait_hpd_asserted() in struct drm_dp_aux Date: Mon, 18 Apr 2022 09:56:40 -0700 Message-Id: <20220418095557.v2.2.Icea616f57331fbaa3d48c529f300c9a8ebd37fb5@changeid> X-Mailer: git-send-email 2.36.0.rc0.470.gd361397f0d-goog In-Reply-To: <20220418165642.2218514-1-dianders@chromium.org> References: <20220418165642.2218514-1-dianders@chromium.org> MIME-Version: 1.0 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: Douglas Anderson , Sankeerth Billakanti , Philip Chen , David Airlie , linux-kernel@vger.kernel.org, Abhinav Kumar , Robert Foss , Stephen Boyd , Thierry Reding , Hsin-Yi Wang , Dmitry Baryshkov , Sam Ravnborg Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Let's add support for being able to read the HPD pin even if it's hooked directly to the controller. This will allow us to get more accurate delays also lets us take away the waiting in the AUX transfer functions of the eDP controller drivers. Signed-off-by: Douglas Anderson --- Changes in v2: - Change is_hpd_asserted() to wait_hpd_asserted() drivers/gpu/drm/panel/panel-edp.c | 33 +++++++++++++++++++++---------- 1 file changed, 23 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/panel/panel-edp.c b/drivers/gpu/drm/panel/panel-edp.c index 1732b4f56e38..086e0bf52fb9 100644 --- a/drivers/gpu/drm/panel/panel-edp.c +++ b/drivers/gpu/drm/panel/panel-edp.c @@ -417,6 +417,11 @@ static int panel_edp_get_hpd_gpio(struct device *dev, struct panel_edp *p) return 0; } +static bool panel_edp_can_read_hpd(struct panel_edp *p) +{ + return !p->no_hpd && (p->hpd_gpio || (p->aux && p->aux->wait_hpd_asserted)); +} + static int panel_edp_prepare_once(struct panel_edp *p) { struct device *dev = p->base.dev; @@ -441,17 +446,21 @@ static int panel_edp_prepare_once(struct panel_edp *p) if (delay) msleep(delay); - if (p->hpd_gpio) { + if (panel_edp_can_read_hpd(p)) { if (p->desc->delay.hpd_absent) hpd_wait_us = p->desc->delay.hpd_absent * 1000UL; else hpd_wait_us = 2000000; - err = readx_poll_timeout(gpiod_get_value_cansleep, p->hpd_gpio, - hpd_asserted, hpd_asserted, - 1000, hpd_wait_us); - if (hpd_asserted < 0) - err = hpd_asserted; + if (p->hpd_gpio) { + err = readx_poll_timeout(gpiod_get_value_cansleep, + p->hpd_gpio, hpd_asserted, + hpd_asserted, 1000, hpd_wait_us); + if (hpd_asserted < 0) + err = hpd_asserted; + } else { + err = p->aux->wait_hpd_asserted(p->aux, hpd_wait_us); + } if (err) { if (err != -ETIMEDOUT) @@ -532,18 +541,22 @@ static int panel_edp_enable(struct drm_panel *panel) /* * If there is a "prepare_to_enable" delay then that's supposed to be * the delay from HPD going high until we can turn the backlight on. - * However, we can only count this if HPD is handled by the panel - * driver, not if it goes to a dedicated pin on the controller. + * However, we can only count this if HPD is readable by the panel + * driver. + * * If we aren't handling the HPD pin ourselves then the best we * can do is assume that HPD went high immediately before we were - * called (and link training took zero time). + * called (and link training took zero time). Note that "no-hpd" + * actually counts as handling HPD ourselves since we're doing the + * worst case delay (in prepare) ourselves. * * NOTE: if we ever end up in this "if" statement then we're * guaranteed that the panel_edp_wait() call below will do no delay. * It already handles that case, though, so we don't need any special * code for it. */ - if (p->desc->delay.prepare_to_enable && !p->hpd_gpio && !p->no_hpd) + if (p->desc->delay.prepare_to_enable && + !panel_edp_can_read_hpd(p) && !p->no_hpd) delay = max(delay, p->desc->delay.prepare_to_enable); if (delay)