From patchwork Fri Feb 10 08:50:45 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Timo Aaltonen X-Patchwork-Id: 1740383 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4PCnXF22j1z23hX for ; Fri, 10 Feb 2023 19:51:25 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1pQP7k-0003Ix-G3; Fri, 10 Feb 2023 08:51:16 +0000 Received: from smtp-relay-canonical-0.internal ([10.131.114.83] helo=smtp-relay-canonical-0.canonical.com) by huckleberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1pQP7Z-00036m-4Q for kernel-team@lists.ubuntu.com; Fri, 10 Feb 2023 08:51:05 +0000 Received: from localhost.localdomain (1.general.tjaalton.uk.vpn [10.172.193.56]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by smtp-relay-canonical-0.canonical.com (Postfix) with ESMTPSA id 54BA2400D2 for ; Fri, 10 Feb 2023 08:51:04 +0000 (UTC) From: Timo Aaltonen To: kernel-team@lists.ubuntu.com Subject: [PATCH 1/8] PCI: Fix used_buses calculation in pci_scan_child_bus_extend() Date: Fri, 10 Feb 2023 10:50:45 +0200 Message-Id: <20230210085052.3083756-2-tjaalton@ubuntu.com> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20230210085052.3083756-1-tjaalton@ubuntu.com> References: <20230210085052.3083756-1-tjaalton@ubuntu.com> MIME-Version: 1.0 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Mika Westerberg BugLink: https://bugs.launchpad.net/bugs/1991366 pci_scan_bridge_extend() returns the subordinate bus number needed to cover all the buses below a bridge. pci_scan_child_bus_extend() computes the number of buses to reserve by comparing that with the current max bus number. Previously it did the subtraction in the wrong order, so 'used_buses' was nonsense. Subtract 'max' from 'cmax' as is done for the similar pci_scan_bridge_extend() call in the following block. Link: https://bugzilla.kernel.org/show_bug.cgi?id=216000 Fixes: 3374c545c27c ("PCI: Account for all bridges on bus when distributing bus numbers") Link: https://lore.kernel.org/r/20220905080232.36087-2-mika.westerberg@linux.intel.com Reported-by: Chris Chiu Tested-by: Chris Chiu Signed-off-by: Mika Westerberg Signed-off-by: Bjorn Helgaas Reviewed-by: Andy Shevchenko (cherry picked from commit 8066cc86b7aaaf6b4b38a81932459c6450440daa) Signed-off-by: Timo Aaltonen --- drivers/pci/probe.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 4948531481d1..d7073b06dbc5 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2917,8 +2917,8 @@ static unsigned int pci_scan_child_bus_extend(struct pci_bus *bus, * hotplug bridges too much during the second scan below. */ used_buses++; - if (cmax - max > 1) - used_buses += cmax - max - 1; + if (max - cmax > 1) + used_buses += max - cmax - 1; } /* Scan bridges that need to be reconfigured */