From nobody Thu Jun 18 17:04:22 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 40C42C433F5 for ; Mon, 18 Apr 2022 16:58:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346729AbiDRRBX (ORCPT ); Mon, 18 Apr 2022 13:01:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40646 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238355AbiDRRBR (ORCPT ); Mon, 18 Apr 2022 13:01:17 -0400 Received: from mail-pl1-x62f.google.com (mail-pl1-x62f.google.com [IPv6:2607:f8b0:4864:20::62f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 411C5265 for ; Mon, 18 Apr 2022 09:58:35 -0700 (PDT) Received: by mail-pl1-x62f.google.com with SMTP id s17so1974201plg.9 for ; Mon, 18 Apr 2022 09:58:35 -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=6oixKBcCsCGFR4aUQt/tdt+p4qsIdjpTUDNTqLJ+UgM=; b=DsxdfJZZnKidzVPkjEN8yyUDWjCsJqByNG9+TdHU4o42WMmxNPH8Yp36mIV/daIscW 7cNxu8SvonrXTSDpOOOipLirQYrOlf16tNmZ0+vxdb/wGZXfxZA404ipdOazg3I/OkrM 0+zvrl6X1pFZbr0+SitCe57qkBRmdQco5No2g= 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=6oixKBcCsCGFR4aUQt/tdt+p4qsIdjpTUDNTqLJ+UgM=; b=d6yBl3H/wNBzK5r6WfwxJ/PE5JcVyyVlfPi1m6lKy0caD/MfVCWDn7D+gXMN22Umed cg5zNPc8bR8FMmyWmanlilgwKlpn/Mi/PIq7DBwnsu05ihSYHlggxwISUxYXG0nSUTp2 73iWcg1uISooWZr9OCDZCapJ0/CCnAgEFNBmTAM1Wbl+iVFUee8Mqrg+hHQ1K6OdtFfH j4GIJs8ADoihqWvbGXbtCyIFoImQDnme7DVt4Q3CzH/nw3bIAAlujdWV2JUUpusgipXV xJsGVqQwVlrYNDUorgNLPKSQt2Hmqga+UuG9EdzLrzVUCLKcPkbEERxmM5df16QHLuTq WtkQ== X-Gm-Message-State: AOAM532cZ9GC1DBbpk9DvTzLUDkcp63n7g94nBv81RNx/YMEdGXP232e u6yI9o167fRfJdSAQs6wDLTbyA== X-Google-Smtp-Source: ABdhPJw5Ni08pwShHanj9IT5Yn5mjBegsZi5inslW8DtFVC0iBkiQhglSWrJEcEEcbje89EQVRuy/A== X-Received: by 2002:a17:902:70c8:b0:156:509b:68e3 with SMTP id l8-20020a17090270c800b00156509b68e3mr11594454plt.113.1650301114799; Mon, 18 Apr 2022 09:58:34 -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.18.2022.04.18.09.58.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 18 Apr 2022 09:58:34 -0700 (PDT) From: Douglas Anderson To: dri-devel@lists.freedesktop.org Cc: Stephen Boyd , Abhinav Kumar , Dmitry Baryshkov , Philip Chen , Robert Foss , Sankeerth Billakanti , Hsin-Yi Wang , Douglas Anderson , Daniel Vetter , David Airlie , Jani Nikula , Kees Cook , Lyude Paul , Maxime Ripard , linux-kernel@vger.kernel.org Subject: [PATCH v2 1/4] drm/dp: Add wait_hpd_asserted() callback to struct drm_dp_aux Date: Mon, 18 Apr 2022 09:56:39 -0700 Message-Id: <20220418095557.v2.1.Icf57bb12233a47727013c6ab69eebf803e22ebc1@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 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Sometimes it's useful for users of the DP AUX bus (like panels) to be able to poll HPD. Let's add a callback that allows DP AUX busses drivers to provide this. Suggested-by: Dmitry Baryshkov Signed-off-by: Douglas Anderson --- Left Dmitry's Reviewed-by tag off since patch changed enough. Changes in v2: - Change is_hpd_asserted() to wait_hpd_asserted() include/drm/dp/drm_dp_helper.h | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/include/drm/dp/drm_dp_helper.h b/include/drm/dp/drm_dp_helper.h index 53d1e722f4de..0940c415db8c 100644 --- a/include/drm/dp/drm_dp_helper.h +++ b/include/drm/dp/drm_dp_helper.h @@ -2035,6 +2035,32 @@ struct drm_dp_aux { ssize_t (*transfer)(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg); =20 + /** + * @wait_hpd_asserted: wait for HPD to be asserted + * + * This is mainly useful for eDP panels drivers to wait for an eDP + * panel to finish powering on. This is an optional function. + * + * This function will efficiently wait for up to `wait_us` microseconds + * for HPD to be asserted and might sleep. + * + * This function returns 0 if HPD was asserted or -ETIMEDOUT if time + * expired and HPD wasn't asserted. This function should not print + * timeout errors to the log. + * + * The semantics of this function are designed to match the + * readx_poll_timeout() function. That means a `wait_us` of 0 means + * to wait forever. If you want to do a quick poll you could pass 1 + * for `wait_us`. + * + * NOTE: this function specifically reports the state of the HPD pin + * that's associated with the DP AUX channel. This is different from + * the HPD concept in much of the rest of DRM which is more about + * physical presence of a display. For eDP, for instance, a display is + * assumed always present even if the HPD pin is deasserted. + */ + int (*wait_hpd_asserted)(struct drm_dp_aux *aux, unsigned long wait_us); + /** * @i2c_nack_count: Counts I2C NACKs, used for DP validation. */ --=20 2.36.0.rc0.470.gd361397f0d-goog From nobody Thu Jun 18 17:04:22 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8ABA7C433EF for ; Mon, 18 Apr 2022 16:58:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238355AbiDRRBa (ORCPT ); Mon, 18 Apr 2022 13:01:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40650 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240968AbiDRRBS (ORCPT ); Mon, 18 Apr 2022 13:01:18 -0400 Received: from mail-pj1-x102f.google.com (mail-pj1-x102f.google.com [IPv6:2607:f8b0:4864:20::102f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F128528A for ; Mon, 18 Apr 2022 09:58:36 -0700 (PDT) Received: by mail-pj1-x102f.google.com with SMTP id bx5so13455696pjb.3 for ; Mon, 18 Apr 2022 09:58:36 -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=6TC7HJArcIe+9Q52cihB9QJ+EHy53InzrBDvCp+njHIDnULKz2SZBYF9qDIwyh+kah RqJPlH9PXEIyEkEW0bdIdp3SEv2i6LRCHgR5Mat6AC2LsF3FkB7WIoJi4q708zEDVgIA naw3Jxf5inor+vwXvgNStbwg9B7tSL5qOj8iW/2pbgkuWASh2dyltDIB0Ao36HWO2lsv 3ytvsuncWWbALl0n+6FfEZxVwTvzxltmWx5155XS2UBhKfDzutmHgP7XTYuxCeqt0XKc JwKPMpvt3KG23RYS6jcqif6D4T0/7oL7vWJ3o1YQU/NVujAOGi5LFFOlN7FJ14SOVF8G FKbQ== X-Gm-Message-State: AOAM533dAf+X6lKJxM55uszwszy3X9ul/7PkdPSZB4BUv7VoYE5ju9d/ mHJnz583mrkw76o+byd1wkZKig== 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 Cc: Stephen Boyd , Abhinav Kumar , Dmitry Baryshkov , Philip Chen , Robert Foss , Sankeerth Billakanti , Hsin-Yi Wang , Douglas Anderson , Daniel Vetter , David Airlie , Sam Ravnborg , Thierry Reding , linux-kernel@vger.kernel.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 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" 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/pane= l-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; } =20 +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 =3D p->base.dev; @@ -441,17 +446,21 @@ static int panel_edp_prepare_once(struct panel_edp *p) if (delay) msleep(delay); =20 - if (p->hpd_gpio) { + if (panel_edp_can_read_hpd(p)) { if (p->desc->delay.hpd_absent) hpd_wait_us =3D p->desc->delay.hpd_absent * 1000UL; else hpd_wait_us =3D 2000000; =20 - err =3D readx_poll_timeout(gpiod_get_value_cansleep, p->hpd_gpio, - hpd_asserted, hpd_asserted, - 1000, hpd_wait_us); - if (hpd_asserted < 0) - err =3D hpd_asserted; + if (p->hpd_gpio) { + err =3D readx_poll_timeout(gpiod_get_value_cansleep, + p->hpd_gpio, hpd_asserted, + hpd_asserted, 1000, hpd_wait_us); + if (hpd_asserted < 0) + err =3D hpd_asserted; + } else { + err =3D p->aux->wait_hpd_asserted(p->aux, hpd_wait_us); + } =20 if (err) { if (err !=3D -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 =3D max(delay, p->desc->delay.prepare_to_enable); =20 if (delay) --=20 2.36.0.rc0.470.gd361397f0d-goog From nobody Thu Jun 18 17:04:22 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 66A2DC433EF for ; Mon, 18 Apr 2022 16:58:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346738AbiDRRBZ (ORCPT ); Mon, 18 Apr 2022 13:01:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40648 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240655AbiDRRBS (ORCPT ); Mon, 18 Apr 2022 13:01:18 -0400 Received: from mail-pj1-x1030.google.com (mail-pj1-x1030.google.com [IPv6:2607:f8b0:4864:20::1030]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7A71928D for ; Mon, 18 Apr 2022 09:58:38 -0700 (PDT) Received: by mail-pj1-x1030.google.com with SMTP id z6-20020a17090a398600b001cb9fca3210so14586869pjb.1 for ; Mon, 18 Apr 2022 09:58:38 -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=J1QFnxHD7U+Ao84z0nfTT0ExEc1/lOyohaOkN2UcR24=; b=CZbSmX/i5jES+5RWi+JOQsTJ2Htdbaoh7NlFmpocxP9XJuCHQj17CZXDzULn6D0fJG BXEBtnF6OUJcmQdxRkGDdkfYv2lUHKb2IGR8K4BpW7neWgAsyfcPK2xKLcEtZinPGwSy PnuNQocQ/bQF5MGtIvlphUKzBsHaJYDutd6TA= 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=J1QFnxHD7U+Ao84z0nfTT0ExEc1/lOyohaOkN2UcR24=; b=JtJtT5oujD0VdJe1FHJdl3XJYV+h/xKn83bOLjlVOqkMr/LV3B0oG4k73HMCigVm7P rz23Ypd98+/7M1BJwKcgjXcIiv/mBBalFYVz5cRnajTJ4lzwxf5BHA92nCxafz5tKP2J 8LiSSC8aPJ59RJtl/zFege2i8H7xZZgEAEUxv/fdXtUyc+sVBbebnaVKTeEz75RaXpDW 0xv5IkMkMc6hV1+u58dTLTLdFwPUuq8y/WSv/O4LH4Slj+WkvdKVKFOOzY5M6noJBDUB fkypYzmtsJtBYkUbUAyI7xAwF2ZueWqv0yCs2b6A7FqdNyOU8kzkuF3KgTfD8JzswWMR I4qg== X-Gm-Message-State: AOAM5329ct6akHYQweWk0+razp1Jh1Aif3OiP8CV3cE5+np0ZiXKheEg T9GrlEu4CVXzQKyaAZ42gaO1Ig== X-Google-Smtp-Source: ABdhPJwLdYhma2u6XQc+ES5orztwhXRFtVhZ1lMWtpfsGvAB78t7vY39NXx+5ntfYDoatZnLspf7yw== X-Received: by 2002:a17:90b:1891:b0:1d2:66e1:62b2 with SMTP id mn17-20020a17090b189100b001d266e162b2mr11793459pjb.56.1650301118033; Mon, 18 Apr 2022 09:58:38 -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.18.2022.04.18.09.58.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 18 Apr 2022 09:58:37 -0700 (PDT) From: Douglas Anderson To: dri-devel@lists.freedesktop.org Cc: Stephen Boyd , Abhinav Kumar , Dmitry Baryshkov , Philip Chen , Robert Foss , Sankeerth Billakanti , Hsin-Yi Wang , Douglas Anderson , Daniel Vetter , David Airlie , Sam Ravnborg , Thierry Reding , linux-kernel@vger.kernel.org Subject: [PATCH v2 3/4] drm/panel: atna33xc20: Take advantage of wait_hpd_asserted() in struct drm_dp_aux Date: Mon, 18 Apr 2022 09:56:41 -0700 Message-Id: <20220418095557.v2.3.I9ee239f6b95b944c8fa030f300ad222a7af9899d@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 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Let's add support for being able to read the HPD pin even if it's hooked directly to the controller. This will let 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() .../gpu/drm/panel/panel-samsung-atna33xc20.c | 38 ++++++++++++------- 1 file changed, 25 insertions(+), 13 deletions(-) diff --git a/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c b/drivers/gpu= /drm/panel/panel-samsung-atna33xc20.c index 20666b6217e7..7f9af3e9aeb8 100644 --- a/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c +++ b/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c @@ -19,6 +19,10 @@ #include #include =20 +/* T3 VCC to HPD high is max 200 ms */ +#define HPD_MAX_MS 200 +#define HPD_MAX_US (HPD_MAX_MS * 1000) + struct atana33xc20_panel { struct drm_panel base; bool prepared; @@ -30,6 +34,7 @@ struct atana33xc20_panel { =20 struct regulator *supply; struct gpio_desc *el_on3_gpio; + struct drm_dp_aux *aux; =20 struct edid *edid; =20 @@ -90,20 +95,25 @@ static int atana33xc20_resume(struct device *dev) return ret; p->powered_on_time =3D ktime_get(); =20 - /* - * Handle HPD. Note: if HPD is hooked up to a dedicated pin on the - * eDP controller then "no_hpd" will be false _and_ "hpd_gpio" will be - * NULL. It's up to the controller driver to wait for HPD after - * preparing the panel in that case. - */ if (p->no_hpd) { - /* T3 VCC to HPD high is max 200 ms */ - msleep(200); - } else if (p->hpd_gpio) { - ret =3D readx_poll_timeout(gpiod_get_value_cansleep, p->hpd_gpio, - hpd_asserted, hpd_asserted, - 1000, 200000); - if (!hpd_asserted) + msleep(HPD_MAX_MS); + } else { + if (p->hpd_gpio) + ret =3D readx_poll_timeout(gpiod_get_value_cansleep, + p->hpd_gpio, hpd_asserted, + hpd_asserted, 1000, HPD_MAX_US); + else if (p->aux->wait_hpd_asserted) + ret =3D p->aux->wait_hpd_asserted(p->aux, HPD_MAX_US); + + /* + * Note that it's possible that no_hpd is false, hpd_gpio is + * NULL, and wait_hpd_asserted is NULL. This is because + * wait_hpd_asserted() is optional even if HPD is hooked up to + * a dedicated pin on the eDP controller. In this case we just + * assume that the controller driver will wait for HPD at the + * right times. + */ + if (!hpd_asserted && (p->hpd_gpio || p->aux->wait_hpd_asserted)) dev_warn(dev, "Timeout waiting for HPD\n"); } =20 @@ -263,6 +273,8 @@ static int atana33xc20_probe(struct dp_aux_ep_device *a= ux_ep) return -ENOMEM; dev_set_drvdata(dev, panel); =20 + panel->aux =3D aux_ep->aux; + panel->supply =3D devm_regulator_get(dev, "power"); if (IS_ERR(panel->supply)) return dev_err_probe(dev, PTR_ERR(panel->supply), --=20 2.36.0.rc0.470.gd361397f0d-goog From nobody Thu Jun 18 17:04:22 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1392FC433F5 for ; Mon, 18 Apr 2022 16:59:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346740AbiDRRBg (ORCPT ); Mon, 18 Apr 2022 13:01:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40672 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346696AbiDRRBU (ORCPT ); Mon, 18 Apr 2022 13:01:20 -0400 Received: from mail-pl1-x635.google.com (mail-pl1-x635.google.com [IPv6:2607:f8b0:4864:20::635]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5A3F32AD for ; Mon, 18 Apr 2022 09:58:40 -0700 (PDT) Received: by mail-pl1-x635.google.com with SMTP id j8so12782060pll.11 for ; Mon, 18 Apr 2022 09:58:40 -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=Dgl5eKn4iSzXB9l06M4fwVd6TIsHNtzaSHHFv1Wa9zw=; b=BZQFA9pcqNGWWm/TFoYFFVZdh6KTVdcVLfXm/LYOkpxORHlZJkWyJzamzdep7WPyws ZJPpjlwYhKtM38pYvGQB8OV5r2gkjnNdFrinAOXarjmIh5CKSeQ/Vs4R8ZuF+eIU37zE vXeyRDrb56V0yWMcCRSp96qh6Aytunonn02UM= 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=Dgl5eKn4iSzXB9l06M4fwVd6TIsHNtzaSHHFv1Wa9zw=; b=4GBEQJn/jKPrvpkV2ltiZcdTRFCPiQrLWMxLI4bZ3NnMltBl62TafLIScrXM7AVpNN /CaJLOy8lUEWlNRNp6fM+lLJUV3k1qo/fR3OFdrrSE6cL+2ZFqgntMU35LP/7y2iCsHF A/kPbmAHeEK51EjIBFCcT9XGEWp98RFR9Te/4s7kgJodTPiWyzSkHSwyxcyBbzAuILYO lqUFLUY/bKktArVPbO262uoFgGDNFeXXAuADfUzcqcfXDbTcVDnEL8KVkvUafCa9CVVv JeosrbEvQr2E/IuXDBJ6cGJQibrKUts6Q4ssXMzsjQcy8n5wrlp+R7DC7zDyX0dLtRZp XFWA== X-Gm-Message-State: AOAM533KZoAs69M6CuXJJ67/v/CFqpqREte4cwX9rE0muTVXnjz0RDmx l19/o4vvrASINVEwFQbZZRxK7Q== X-Google-Smtp-Source: ABdhPJxQVsYC/f7eoCzdIS38t+LLRJmAkBiI96AdewmBzcUliQs0YJQ/uNxYdYHYGIw1Keing25HWQ== X-Received: by 2002:a17:90a:c781:b0:1d0:c23e:5842 with SMTP id gn1-20020a17090ac78100b001d0c23e5842mr18487206pjb.182.1650301119843; Mon, 18 Apr 2022 09:58:39 -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.18.2022.04.18.09.58.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 18 Apr 2022 09:58:39 -0700 (PDT) From: Douglas Anderson To: dri-devel@lists.freedesktop.org Cc: Stephen Boyd , Abhinav Kumar , Dmitry Baryshkov , Philip Chen , Robert Foss , Sankeerth Billakanti , Hsin-Yi Wang , Douglas Anderson , Andrzej Hajda , Daniel Vetter , David Airlie , Jernej Skrabec , Jonas Karlman , Laurent Pinchart , Neil Armstrong , linux-kernel@vger.kernel.org Subject: [PATCH v2 4/4] drm/bridge: parade-ps8640: Provide wait_hpd_asserted() in struct drm_dp_aux Date: Mon, 18 Apr 2022 09:56:42 -0700 Message-Id: <20220418095557.v2.4.Ie827321ce263be52fdb8c1276f6f8cc00d78029f@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 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" This implements the callback added by the patch ("drm/dp: Add wait_hpd_asserted() callback to struct drm_dp_aux"). With this change and all the two "DP AUX Endpoint" drivers changed to use wait_hpd_asserted(), we no longer need to have an long delay in the AUX transfer function. It's up to the panel code to make sure that the panel is powered now. If someone tried to call the aux transfer function without making sure the panel is powered we'll just get a normal transfer failure. We'll still keep the wait for HPD in the pre_enable() function. Though it's probably not actually needed there, this driver is used in the old mode (pre-DP AUX Endpoints) and it may be important for those cases. If nothing else, it shouldn't cause any big problems. Signed-off-by: Douglas Anderson --- Changes in v2: - Change is_hpd_asserted() to wait_hpd_asserted() drivers/gpu/drm/bridge/parade-ps8640.c | 34 ++++++++++++++++---------- 1 file changed, 21 insertions(+), 13 deletions(-) diff --git a/drivers/gpu/drm/bridge/parade-ps8640.c b/drivers/gpu/drm/bridg= e/parade-ps8640.c index 9766cbbd62ad..2f19a8c89880 100644 --- a/drivers/gpu/drm/bridge/parade-ps8640.c +++ b/drivers/gpu/drm/bridge/parade-ps8640.c @@ -168,23 +168,30 @@ static bool ps8640_of_panel_on_aux_bus(struct device = *dev) return true; } =20 -static int ps8640_ensure_hpd(struct ps8640 *ps_bridge) +static int _ps8640_wait_hpd_asserted(struct ps8640 *ps_bridge, unsigned lo= ng wait_us) { struct regmap *map =3D ps_bridge->regmap[PAGE2_TOP_CNTL]; - struct device *dev =3D &ps_bridge->page[PAGE2_TOP_CNTL]->dev; int status; - int ret; =20 /* * Apparently something about the firmware in the chip signals that * HPD goes high by reporting GPIO9 as high (even though HPD isn't * actually connected to GPIO9). */ - ret =3D regmap_read_poll_timeout(map, PAGE2_GPIO_H, status, - status & PS_GPIO9, 20 * 1000, 200 * 1000); + return regmap_read_poll_timeout(map, PAGE2_GPIO_H, status, + status & PS_GPIO9, wait_us / 10, wait_us); +} =20 - if (ret < 0) - dev_warn(dev, "HPD didn't go high: %d\n", ret); +static int ps8640_wait_hpd_asserted(struct drm_dp_aux *aux, unsigned long = wait_us) +{ + struct ps8640 *ps_bridge =3D aux_to_ps8640(aux); + struct device *dev =3D &ps_bridge->page[PAGE0_DP_CNTL]->dev; + int ret; + + pm_runtime_get_sync(dev); + ret =3D _ps8640_wait_hpd_asserted(ps_bridge, wait_us); + pm_runtime_mark_last_busy(dev); + pm_runtime_put_autosuspend(dev); =20 return ret; } @@ -323,9 +330,7 @@ static ssize_t ps8640_aux_transfer(struct drm_dp_aux *a= ux, int ret; =20 pm_runtime_get_sync(dev); - ret =3D ps8640_ensure_hpd(ps_bridge); - if (!ret) - ret =3D ps8640_aux_transfer_msg(aux, msg); + ret =3D ps8640_aux_transfer_msg(aux, msg); pm_runtime_mark_last_busy(dev); pm_runtime_put_autosuspend(dev); =20 @@ -369,8 +374,8 @@ static int __maybe_unused ps8640_resume(struct device *= dev) * Mystery 200 ms delay for the "MCU to be ready". It's unclear if * this is truly necessary since the MCU will already signal that * things are "good to go" by signaling HPD on "gpio 9". See - * ps8640_ensure_hpd(). For now we'll keep this mystery delay just in - * case. + * _ps8640_wait_hpd_asserted(). For now we'll keep this mystery delay + * just in case. */ msleep(200); =20 @@ -406,7 +411,9 @@ static void ps8640_pre_enable(struct drm_bridge *bridge) int ret; =20 pm_runtime_get_sync(dev); - ps8640_ensure_hpd(ps_bridge); + ret =3D _ps8640_wait_hpd_asserted(ps_bridge, 200 * 1000); + if (ret < 0) + dev_warn(dev, "HPD didn't go high: %d\n", ret); =20 /* * The Manufacturer Command Set (MCS) is a device dependent interface @@ -652,6 +659,7 @@ static int ps8640_probe(struct i2c_client *client) ps_bridge->aux.name =3D "parade-ps8640-aux"; ps_bridge->aux.dev =3D dev; ps_bridge->aux.transfer =3D ps8640_aux_transfer; + ps_bridge->aux.wait_hpd_asserted =3D ps8640_wait_hpd_asserted; drm_dp_aux_init(&ps_bridge->aux); =20 pm_runtime_enable(dev); --=20 2.36.0.rc0.470.gd361397f0d-goog