From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.tuxedocomputers.com (mail.tuxedocomputers.com [157.90.84.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 35B0A3019DE; Tue, 28 Oct 2025 10:26:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=157.90.84.7 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761647218; cv=none; b=mbgOuTEaAeYWIOTlV/IBr6qUOcNOtS0Dj7Bprx3kChqXcvLAsZxAaFO/15vyWTGiZYnU641vKbQXGJe1GgYX1FdWqE4ktDWa9/bS5iXAuGvhcVRyMPJ8PS3qG+sSNSYe3Bmxg8UrcDf89ELQ5/I/Y3eQpeRDvmczu8ye6SVaTow= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761647218; c=relaxed/simple; bh=fGPfVLmHb+wl9h4eE562Vwd7sPPgvOxQ4yq0Gh3pNIk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=dWj+iMmgxbPSVWOxlRCBeKw5D393To2+C2h7hFne559RFonIat/F+7dNJfHfr0xRN8A9f0xEXGL3i2T3jMnMmdebWlcqabhTebe7Kc1ul0bqolS7SQ140Dq7bgFHJb0HQbM2VFY8KO89qtlYCIfWNkrgQ9n6F1razh+dxEtsveg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=tuxedocomputers.com; spf=pass smtp.mailfrom=tuxedocomputers.com; dkim=pass (1024-bit key) header.d=tuxedocomputers.com header.i=@tuxedocomputers.com header.b=QmTHE+1z; arc=none smtp.client-ip=157.90.84.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=tuxedocomputers.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=tuxedocomputers.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=tuxedocomputers.com header.i=@tuxedocomputers.com header.b="QmTHE+1z" Received: from [10.10.11.27] (business-24-134-105-141.pool2.vodafone-ip.de [24.134.105.141]) (Authenticated sender: a.erhardt@tuxedocomputers.com) by mail.tuxedocomputers.com (Postfix) with ESMTPSA id 16A932FC004D; Tue, 28 Oct 2025 11:16:52 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tuxedocomputers.com; s=default; t=1761646613; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=AMx59YWeliqF/lFY/+ujXIhGSvd8cbjYB40wlB1RYFA=; b=QmTHE+1zUU91L74zpwra1sUslqOLhjB8in8RHnroIZSWxQ6lBjrUjbIVH+zGHq++nET7u/ yusdq9wdM0bxM+vKOVtS6z6N71IW27l7SXCBsr4YeMBySbCjoAmDKI2WWgUKx8bZgmaGrn YuJJXxhjlgqW5Vec8+nkonQBlBqJzLc= Authentication-Results: mail.tuxedocomputers.com; auth=pass smtp.auth=a.erhardt@tuxedocomputers.com smtp.mailfrom=aer@tuxedocomputers.com Message-ID: Date: Tue, 28 Oct 2025 11:16:51 +0100 Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v10 3/4] fbcon: Use screen info to find primary device To: "Mario Limonciello (AMD)" , David Airlie , Bjorn Helgaas Cc: Alex Deucher , =?UTF-8?Q?Christian_K=C3=B6nig?= , Simona Vetter , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , "open list:DRM DRIVERS" , open list , "open list:PCI SUBSYSTEM" , Daniel Dadap References: <20250811162606.587759-1-superm1@kernel.org> <20250811162606.587759-4-superm1@kernel.org> Content-Language: en-US From: Aaron Erhardt In-Reply-To: <20250811162606.587759-4-superm1@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On Mon, Aug 11, 2025 at 11:26:05AM -0500, Mario Limonciello (AMD) wrote: > On systems with non VGA GPUs fbcon can't find the primary GPU because > video_is_primary_device() only checks the VGA arbiter. > > Add a screen info check to video_is_primary_device() so that callers > can get accurate data on such systems. I have a question regarding this change. To me, the function name video_is_primary_device() implies that there is only one primary GPU. I would also expect that the 'boot_display' attribute added later in the patch series based on this function is only set for one GPU, but that is not necessarily the case. Since I'm working on a user-space program that reads the 'boot_display' attribute, I need to know what behavior is intended in order to do a correct implementation. > > Reviewed-by: Thomas Zimmermann > Suggested-by: Thomas Zimmermann > Suggested-by: Bjorn Helgaas > Signed-off-by: Mario Limonciello (AMD) > --- > v10: > * Rebase on 6.17-rc1 > * Squash 'fbcon: Stop using screen_info_pci_dev()' > --- > arch/x86/video/video-common.c | 25 ++++++++++++++++++++++++- > 1 file changed, 24 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/video/video-common.c b/arch/x86/video/video-common.c > index 81fc97a2a837a..e0aeee99bc99e 100644 > --- a/arch/x86/video/video-common.c > +++ b/arch/x86/video/video-common.c > @@ -9,6 +9,7 @@ > > #include > #include > +#include > #include > > #include > @@ -27,6 +28,11 @@ EXPORT_SYMBOL(pgprot_framebuffer); > > bool video_is_primary_device(struct device *dev) > { > +#ifdef CONFIG_SCREEN_INFO > + struct screen_info *si = &screen_info; > + struct resource res[SCREEN_INFO_MAX_RESOURCES]; > + ssize_t i, numres; > +#endif > struct pci_dev *pdev; > > if (!dev_is_pci(dev)) > @@ -34,7 +40,24 @@ bool video_is_primary_device(struct device *dev) > > pdev = to_pci_dev(dev); > > - return (pdev == vga_default_device()); > + if (!pci_is_display(pdev)) > + return false; > + > + if (pdev == vga_default_device()) > + return true; This can mark a VGA device as primary GPU. > + > +#ifdef CONFIG_SCREEN_INFO > + numres = screen_info_resources(si, res, ARRAY_SIZE(res)); > + for (i = 0; i < numres; ++i) { > + if (!(res[i].flags & IORESOURCE_MEM)) > + continue; > + > + if (pci_find_resource(pdev, &res[i])) > + return true; > + } > +#endif And then the new code can also choose a primary GPU. > + > + return false; > } > EXPORT_SYMBOL(video_is_primary_device); > In particular, I have hardware that has this exact configuration where two GPUs are marked as primary and have a 'boot_display' attribute: the first one through vga_default_device(), the second one through the new detection method. Is this intended? Kind regards Aaron