From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=195.135.223.131 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793261430; b=weJMrBaoYTXObJr7H7twDk3B72NSGcHfjaF/vXbya//jc8NnU4rRFPH3wmEkD0W8i5W8 WPaEujA4DMmCBPYg5XMgKWEqM3GKa6R8uiAvwpEddFXPoBWUwmM29O598qkTQpqZ2Hjix Z/i/gkbUEN3Nx5lLg2QCsrCOdn1JMnlzxEp6z/Xl7MYta2OzQViwXcbgszKBgmy2XmeFD EVGDkHwtsEHPuXGmwvdzCZlyMi3g6mdps2u44pJyskxwix1cIcZEW4u0XO0hgkXbt1KJa wOsAPoTVpE/UXlBWquqWjhECl5jjOeL2ApFj1VjZxWc/PaFegd6W2IGWpszXUKuBctw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793261430; h=DMARC-Filter:Received:DKIM-Signature:DKIM-Signature:DKIM-Signature: DKIM-Signature:Received:Received:Message-ID:Date:MIME-Version: User-Agent:Subject:To:Cc:References:Content-Language:From:Autocrypt: In-Reply-To:Content-Type:Content-Transfer-Encoding:X-Spam-Flag: X-Spam-Level:X-Spamd-Result:X-Spam-Score; bh=5rBZ0kFvUh2i3PD86rsaq90lGhsDruIK+LJgf4TiufE=; b=FSPVQ44FcmBZ+x1uOT0s1D0XaznArRw2ojVp5gQMeBuRfQQx2QZIxQLg2BzBzWLZkXP1 D7s2yVPRJlzNcmwBZtfatOsG2JXlvXA+dBf3sxocKKZ4oFjEi74CpMhq5S5A0KPYqE/rW KW0NmLHlnX5imFsXhv+wH9PGiYO3pB93PUnd+7TFZ4EY1v5cmTeIhjobNAEfcJZPS0r8G or2NmQBrqXnXERxFc9yLEYkf30KKC1UauIKzJNxjZ1i61qjW08lf27M7fHYSnCJ/jhOkp 5PTfTz2l7Ihz22ZcNAY9e+FuugX+NJH1fmdvF3zkQsg1afGLEicODkKlAtgQEcxQ3wg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=suse.de; spf=pass smtp.mailfrom=suse.de; dkim=pass header.d=suse.de header.i=@suse.de header.a=rsa-sha256 header.s=susede2_rsa header.b=fJqSyjMR; dkim=pass header.d=suse.de header.i=@suse.de header.a=ed25519-sha256 header.s=susede2_ed25519 header.b="mT+3/vZE"; dkim=pass header.d=suse.de header.i=@suse.de header.a=rsa-sha256 header.s=susede2_rsa header.b=fJqSyjMR; dkim=neutral header.d=suse.de header.i=@suse.de header.a=ed25519-sha256 header.s=susede2_ed25519 header.b="mT+3/vZE"; arc=none smtp.remote-ip=195.135.223.131 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.223.131]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1E9DB606A31F; Thu, 29 Oct 2026 08:10:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 1E9DB606A31F Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=suse.de header.i=@suse.de header.a=rsa-sha256 header.s=susede2_rsa header.b=fJqSyjMR; dkim=pass header.d=suse.de header.i=@suse.de header.a=ed25519-sha256 header.s=susede2_ed25519 header.b=mT+3/vZE; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.a=rsa-sha256 header.s=susede2_rsa header.b=fJqSyjMR; dkim=neutral header.d=suse.de header.i=@suse.de header.a=ed25519-sha256 header.s=susede2_ed25519 header.b=mT+3/vZE Received: from imap1.dmz-prg2.suse.org (unknown [10.150.64.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 1AB351F385; Thu, 29 Oct 2026 08:10:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1793261428; h=from:from:reply-to: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:autocrypt:autocrypt; bh=5rBZ0kFvUh2i3PD86rsaq90lGhsDruIK+LJgf4TiufE=; b=fJqSyjMR123MaZQ++4XcOMlHl3DGd8R/7vEzojiPss9ZF4DefVlIxSzLA9+rKt9UfgFTNb LL7QBh/a6lsec0KelDwGMENnoJC2fUn3jaPCnJRCLt97g1ghdsT3fZsBM5dV+ek3nQjPSa pqGgft5un3mV+q0kVIpPNOwx6S96wMQ= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1793261428; h=from:from:reply-to: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:autocrypt:autocrypt; bh=5rBZ0kFvUh2i3PD86rsaq90lGhsDruIK+LJgf4TiufE=; b=mT+3/vZEIfsBnC6J3GUTIoeq8FKF3UhUq5yQcaqSTDW/qVydR8OWHyyOdIeBbQuQse+1z3 zweUVYwqht1iZsCA== Authentication-Results: smtp-out2.suse.de; none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1793261428; h=from:from:reply-to: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:autocrypt:autocrypt; bh=5rBZ0kFvUh2i3PD86rsaq90lGhsDruIK+LJgf4TiufE=; b=fJqSyjMR123MaZQ++4XcOMlHl3DGd8R/7vEzojiPss9ZF4DefVlIxSzLA9+rKt9UfgFTNb LL7QBh/a6lsec0KelDwGMENnoJC2fUn3jaPCnJRCLt97g1ghdsT3fZsBM5dV+ek3nQjPSa pqGgft5un3mV+q0kVIpPNOwx6S96wMQ= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1793261428; h=from:from:reply-to: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:autocrypt:autocrypt; bh=5rBZ0kFvUh2i3PD86rsaq90lGhsDruIK+LJgf4TiufE=; b=mT+3/vZEIfsBnC6J3GUTIoeq8FKF3UhUq5yQcaqSTDW/qVydR8OWHyyOdIeBbQuQse+1z3 zweUVYwqht1iZsCA== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id C1E8F13419; Thu, 29 Oct 2026 08:10:27 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id v4IaHnP/4mpvMgAAD6G6ig (envelope-from ); Thu, 29 Oct 2026 08:10:27 +0000 Message-ID: <905d902c-461f-4a0e-9ac2-0ad02fe9cabe@suse.de> Date: Thu, 29 Oct 2026 09:10:27 +0100 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] PCI/VGA: Enable firmware default device detection on LoongArch To: wuqianhai@loongson.cn, bhelgaas@google.com Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, javierm@redhat.com, dri-devel@lists.freedesktop.org References: <20261028094634.766723-1-wuqianhai@loongson.cn> <20261029033440.973077-1-wuqianhai@loongson.cn> Content-Language: en-US From: Thomas Zimmermann Autocrypt: addr=tzimmermann@suse.de; keydata= xsBNBFs50uABCADEHPidWt974CaxBVbrIBwqcq/WURinJ3+2WlIrKWspiP83vfZKaXhFYsdg XH47fDVbPPj+d6tQrw5lPQCyqjwrCPYnq3WlIBnGPJ4/jreTL6V+qfKRDlGLWFjZcsrPJGE0 BeB5BbqP5erN1qylK9i3gPoQjXGhpBpQYwRrEyQyjuvk+Ev0K1Jc5tVDeJAuau3TGNgah4Yc hdHm3bkPjz9EErV85RwvImQ1dptvx6s7xzwXTgGAsaYZsL8WCwDaTuqFa1d1jjlaxg6+tZsB 9GluwvIhSezPgnEmimZDkGnZRRSFiGP8yjqTjjWuf0bSj5rUnTGiyLyRZRNGcXmu6hjlABEB AAHNJ1Rob21hcyBaaW1tZXJtYW5uIDx0emltbWVybWFubkBzdXNlLmRlPsLAjgQTAQgAOAIb AwULCQgHAgYVCgkICwIEFgIDAQIeAQIXgBYhBHIX+6yM6c9jRKFo5WgNwR1TC3ojBQJftODH AAoJEGgNwR1TC3ojx1wH/0hKGWugiqDgLNXLRD/4TfHBEKmxIrmfu9Z5t7vwUKfwhFL6hqvo lXPJJKQpQ2z8+X2vZm/slsLn7J1yjrOsoJhKABDi+3QWWSGkaGwRJAdPVVyJMfJRNNNIKwVb U6B1BkX2XDKDGffF4TxlOpSQzdtNI/9gleOoUA8+jy8knnDYzjBNOZqLG2FuTdicBXblz0Mf vg41gd9kCwYXDnD91rJU8tzylXv03E75NCaTxTM+FBXPmsAVYQ4GYhhgFt8S2UWMoaaABLDe 7l5FdnLdDEcbmd8uLU2CaG4W2cLrUaI4jz2XbkcPQkqTQ3EB67hYkjiEE6Zy3ggOitiQGcqp j//OwE0EWznS4AEIAMYmP4M/V+T5RY5at/g7rUdNsLhWv1APYrh9RQefODYHrNRHUE9eosYb T6XMryR9hT8XlGOYRwKWwiQBoWSDiTMo/Xi29jUnn4BXfI2px2DTXwc22LKtLAgTRjP+qbU6 3Y0xnQN29UGDbYgyyK51DW3H0If2a3JNsheAAK+Xc9baj0LGIc8T9uiEWHBnCH+RdhgATnWW GKdDegUR5BkDfDg5O/FISymJBHx2Dyoklv5g4BzkgqTqwmaYzsl8UxZKvbaxq0zbehDda8lv hFXodNFMAgTLJlLuDYOGLK2AwbrS3Sp0AEbkpdJBb44qVlGm5bApZouHeJ/+n+7r12+lqdsA EQEAAcLAdgQYAQgAIAIbDBYhBHIX+6yM6c9jRKFo5WgNwR1TC3ojBQJftOH6AAoJEGgNwR1T C3ojVSkIALpAPkIJPQoURPb1VWjh34l0HlglmYHvZszJWTXYwavHR8+k6Baa6H7ufXNQtThR yIxJrQLW6rV5lm7TjhffEhxVCn37+cg0zZ3j7zIsSS0rx/aMwi6VhFJA5hfn3T0TtrijKP4A SAQO9xD1Zk9/61JWk8OysuIh7MXkl0fxbRKWE93XeQBhIJHQfnc+YBLprdnxR446Sh8Wn/2D Ya8cavuWf2zrB6cZurs048xe0UbSW5AOSo4V9M0jzYI4nZqTmPxYyXbm30Kvmz0rYVRaitYJ 4kyYYMhuULvrJDMjZRvaNe52tkKAvMevcGdt38H4KSVXAylqyQOW5zvPc4/sq9c= In-Reply-To: <20261029033440.973077-1-wuqianhai@loongson.cn> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Flag: NO X-Spam-Level: X-Spamd-Result: default: False [-13.29 / 50.00]; SUSE_INTERNAL_BYPASS(-9.00)[]; BAYES_HAM(-3.00)[100.00%]; NEURAL_HAM_LONG(-1.00)[-0.998]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; XM_UA_NO_VERSION(0.01)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; MIME_TRACE(0.00)[0:+]; RCVD_TLS_ALL(0.00)[]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; TO_MATCH_ENVRCPT_ALL(0.00)[]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_FIVE(0.00)[6]; FROM_EQ_ENVFROM(0.00)[]; TO_DN_NONE(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; DBL_BLOCKED_OPENRESOLVER(0.00)[imap1.dmz-prg2.suse.org:helo,suse.com:url,bootlin.com:url,loongson.cn:email] X-Spam-Score: -13.29 Hi Am 29.10.26 um 04:34 schrieb wuqianhai@loongson.cn: > From: wuqianhai > > On LoongArch, PCI resource assignment completes during subsys_initcall > (acpi_init), before vga_arb_device_init() runs. By that time the > firmware framebuffer BAR may already have been relocated, leaving > screen_info's lfb_base stale. Enable vga_is_firmware_default() for > LoongArch and refresh screen_info in vga_arb_device_init() before the > boot device is matched. > > Unlike x86, sysfb_primary_display is only defined when CONFIG_SYSFB is > enabled on LoongArch, so have VGA_ARB select SYSFB there. > > Signed-off-by: wuqianhai > --- > Changes in v2: > - Add VGA_ARB's select of SYSFB for LoongArch to avoid an undefined > reference when CONFIG_SCREEN_INFO is not set. > - Restrict the screen_info_apply_fixups() call to CONFIG_LOONGARCH so > x86 and other architectures are unaffected. > - Enable vga_is_firmware_default() for LoongArch. > --- > drivers/pci/Kconfig | 1 + > drivers/pci/vgaarb.c | 12 +++++++++++- > 2 files changed, 12 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig > index 0c7408509ba2..55cc60f5d312 100644 > --- a/drivers/pci/Kconfig > +++ b/drivers/pci/Kconfig > @@ -256,6 +256,7 @@ config VGA_ARB > default y > depends on !S390 > select SCREEN_INFO if X86 > + select SYSFB if LOONGARCH > help > Some "legacy" VGA devices implemented on PCI typically have the same > hard-decoded addresses as they did on ISA. When multiple PCI devices > diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c > index 3e58b2c05c85..1b7e915629f9 100644 > --- a/drivers/pci/vgaarb.c > +++ b/drivers/pci/vgaarb.c > @@ -566,7 +566,7 @@ EXPORT_SYMBOL(vga_put); > > static bool vga_is_firmware_default(struct pci_dev *pdev) > { > -#if defined CONFIG_X86 > +#if defined(CONFIG_X86) || defined(CONFIG_LOONGARCH) > return pdev == screen_info_pci_dev(&sysfb_primary_display.screen); > #else > return false; > @@ -1527,6 +1527,16 @@ static int __init vga_arb_device_init(void) > int rc; > struct pci_dev *pdev; > > +#if defined(CONFIG_LOONGARCH) > + /* > + * On LoongArch, PCI resource assignment completes during > + * subsys_initcall (acpi_init), before the VGA arbiter runs. Refresh > + * screen_info so vga_is_firmware_default() can match the relocated > + * BAR. > + */ > + screen_info_apply_fixups(); > +#endif No per-arch defines in generic code.  All the setup should work the same on all architectures.  All global screen-info state should be maintained by drivers/firmware/sysfb.c. Otherwise the framebuffer setup gets even more convoluted than it already is. My question is why does vga_is_firmware_default() run before sysfb_init()? [1] Does acpi_init call into it? [1] https://elixir.bootlin.com/linux/v7.3/source/drivers/firmware/sysfb.c#L225 Apart from that, we can decouple screen_info_apply_fixups() from sysfb_init().  After relocation happens, the PCI code could call the helper directly and let it update the global screen_info. Best regards Thomas > + > rc = misc_register(&vga_arb_device); > if (rc < 0) > pr_err("error %d registering device\n", rc); -- -- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com GF: Stefan Gaiser, Jochen Jaser, Abhinav Puri, (HRB 36809, AG Nürnberg)