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 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 7FD7FC02198 for ; Tue, 18 Feb 2025 13:33:53 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 6C45C10E058; Tue, 18 Feb 2025 13:33:52 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=netztorte.de header.i=info@netztorte.de header.b="wxr0zCa8"; dkim-atps=neutral X-Greylist: delayed 304 seconds by postgrey-1.36 at gabe; Tue, 18 Feb 2025 13:33:50 UTC Received: from mout.kundenserver.de (mout.kundenserver.de [212.227.126.133]) by gabe.freedesktop.org (Postfix) with ESMTPS id 1DBA210E058 for ; Tue, 18 Feb 2025 13:33:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netztorte.de; s=s1-ionos; t=1739885628; x=1740490428; i=info@netztorte.de; bh=iCjR/95oTaXUnDuLuR9Q5TMrDE09OqfT0MKB4fOsNfs=; h=X-UI-Sender-Class:Date:From:To:Subject:Message-ID:MIME-Version: Content-Type:Content-Transfer-Encoding:cc: content-transfer-encoding:content-type:date:from:message-id: mime-version:reply-to:subject:to; b=wxr0zCa8CvlbhA52YIWmG/JRNKP9pu6WDAlUThpEuEG0AnEIWaM1SNftJJz03Y1W d0qCYPhAV57agKz2JhrMgcHK4zSkcXXOzsuJRS99jwaVbBa0VSLF4JwYynMWiW4kc dhxwWUD3NvOik6IAkFPVXnX7F4qb+M4Qd0Dqf0WFqkLvmMXvswpOmI1GGYLMNe2ft dV51OIqCuadgc9GpoB1pnMt+Ag3CGE8DrEc/U5EporCYnbImdIKqKCNBBPpmd4s04 eFGEjxixRcLimSHKdTRD48XPd2R4zMg7HlB8A3eJXKRubqFsiV5Nn3yY2Burk+A8z chG9MHha7MCw/futNA== X-UI-Sender-Class: 55c96926-9e95-11ee-ae09-1f7a4046a0f6 Received: from localhost ([2.202.64.191]) by mrelayeu.kundenserver.de (mreue011 [212.227.15.167]) with ESMTPSA (Nemesis) id 1MkpKR-1t4CLj3bXr-00b3Gj for ; Tue, 18 Feb 2025 14:28:44 +0100 Date: Tue, 18 Feb 2025 14:28:43 +0100 From: Thorsten Maerz To: dri-devel@lists.freedesktop.org Subject: [Question] gpio-backlight: Is initial power state derived correctly? Message-ID: <20250218142843.00002393@netztorte.de> Organization: Severely Unorganized X-Mailer: Claws Mail 4.1.1 (GTK 3.24.37; x86_64-w64-mingw32) Face: iVBORw0KGgoAAAANSUhEUgAAADAAAAAwBAMAAAClLOS0AAAAFXRFWHRDcmVhdGlvbiBUaW1lAAflAx8LDDHhuF4vAAAAB3RJTUUH5QMfCw4Kt4Q2+QAAAAlwSFlzAAALEgAACxIB0t1+/AAAADBQTFRFzq1j5+fW7+/n7+/v9/f3////////////////////////////////////////////hY5OKQAAAFRJREFUeNpjMMYBGEYlsEgwQIGwMTIbSULZGJk9aHUoCoGBIMhbCPZAhy55EgxIQBmXhPDg1gHiCCoiAEoMCiP7GTnOldEkBl4HKC0hR5GiIpXTFQAAVaS5+Z8eLgAAAABJRU5ErkJggg== MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:6zjutwSCNCDRT2zDIdhimZ64jRKRn5gZBdCRV2Ko14qcLTBbvYt 5xKQXJxFY44B/7nJag5zPn0wAWhvoWDKhZk576IjnwFCk3NYxMorH2FBGuB4hcVTJlyu3bH 32oAZ215GA/Eh8LiHLIxd6TN5V9nkTMBHI6STew1Ij/zeuBuS3J4vVUvgetFVbDZkh63qtG XRG6Ek/Qb9SAQpqne8MyA== UI-OutboundReport: notjunk:1;M01:P0:5jdg+byZXJ8=;23CZQz6irSuWmINN6MnJngfIj2u 1We4O4RGOeAOEwEZB7f14NCiLacpbRMLAfovwqLVDWZa0YB3CoIabm/hwav83/0jpYq4PD8tE +0DBl8SosgGXNvOsIMB/ya1UOkb3Qb1KWPEKtQ2baJbcUqzcCHYicut+ZsX52sZL/aK6j/L74 qrvQjOh7G4rBLwoPHRfRUWDXY2K9caDhaF5FSAE1hOdJ97MDE+BssD/HjMSPqUlFXNZ9vpl/m MryALhmJ3MHJsZLlO0fuInAgeavtCzNRvmmB/UiByrbaY7ddCKwpAlrj32e+G7QAxTJ08Pqqy WVXhbFJMCAUVzEDj5iGwb8W9X44ZcbtJofjYatU8wnBr7l8Dulfhlvo7mR077M9rZcHvdYAlR HKsTGCsR08X83sYnGAfmRzirTd6lE7LwusDriU7S2QLIkqq322SluIkAMr4ULKYfxPBePMYR4 Sktw6YuafJYHd6JIihdwzveKVlR8p8BjI17exSJZ1C+FvfyjHJg+9wFtIEdVdlCn707iPgRVY 28t//5paUJxtgAMLz25jH5eOlDI4qH8jjN8XleLJytWjODG4bI9HWrLRRTjQ+JQ4mzRg5AIsS rUztJoSyH3iNr12vlKAE5GPniufxGQAO7V74ynhrdMAC4d8qS6o1cOR20ZfDRd80/kRZZ4oPP S14VtfO6ScbHEFr1nTTW8/cNCcFeO9JZAnjToSwkVPbR/csXAk81QYSiqaNdU0CaVdJw8JqqE nNG0WOp/w49fLElY/L918+8e3hrrY5sN9UDXwMq66y+i34tbTsD3c/bRDpDpqIP4cKYCOprHc YS4SzC8yr1E/3pKqXgRPRcXJX5U9jIRB85lT6/MjtAIDv8+EauL55ujDVzul8NMyP28k6vuwz kX5HIfm8gTOmQ/nzcJj5YjYCE2cMYMlqocsasRS78S4S7H/0ANnpUGH/kzY6sb0irodlOyyGH EvURBTKwA8ISAmwq4UkOjihcF0Xz+FqB8F9VXxfHR8VoktJy6HR9JItWjmcB2CKZe1DYzPwMe Yf3vcip24fr+9+rs2cQ3hprjCV4esGU3JlOm3u5ZZFg4n8F7e7e3beUaVmwdw4/t+g+mk5IMr TEJY3oM/XDOOjw0QjClFcKjXPx9wykAQzzLmWWsbhRt2lC7E6R6dyqCGY3GussnmgJclMvQLC BiQSQWE/EkC7Cu+nUPlz7LWslGkRL/wpVt6+ZfjtjqZUUGioGMXX+Uzit3VDPdVcQJ3JlN5Fl 1AYGJM2YYNqyWIIk/zItTlO6TQBYW5T/yWQfs8qK3pQPfEBRNOUC8A53/boieUjYianpd9fLm ZwKZ2WBiY15J2kr07SpLJoDjQb6gZZOXoCL8CNbYXVm/FFRyoF5mls/KXcdGlPec/IV 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: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" I am struggling with the gpio-backlight module, it starts up with a black screen, though the devicetree states "default-on": backlight { compatible =3D "gpio-backlight"; gpios =3D <0x31 0x05 0x00>; default-on; }; After bootup, the content of "/sys/class/backlight/backlight/bl_power" is "4", meaning BACKLIGHT_POWER_OFF. The screen is black. (The backlight devicetree section is working, I can switch on backlight by writing "0" (BACKLIGHT_POWER_ON) to bl_power.) It looks to me as if the logic for detecting the devicetree is reversed: See drivers/video/backlight/gpio_backlight.c : =2D--8<--- start def_value =3D device_property_read_bool(dev, "default-on"); [...] /* Set the initial power state */ if (!of_node || !of_node->phandle) /* Not booted with device tree or no phandle link to the n= ode */ bl->props.power =3D def_value ? BACKLIGHT_POWER_ON : BACKLIGHT_POWER_OFF; else if (gpiod_get_value_cansleep(gbl->gpiod) =3D=3D 0) bl->props.power =3D BACKLIGHT_POWER_OFF; else bl->props.power =3D BACKLIGHT_POWER_ON; =2D-->8--- end 1. "def_value" is read from the devicetree. 2. "def_value" is evaluated after "if (!of_node || !of_node->phandle)" Shouldn't the logic be the other way round? if (of_node && of_node->phandle) /* booted with device tree */ bl->props.power =3D def_value ? BACKLIGHT_POWER_ON : BACKLIGHT_POWER_OFF; else [...] /* Not booted with device tree or no phandle link to the n= ode */ =2D- Best regards, Thorsten