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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 981A9CCFA18 for ; Sat, 8 Nov 2025 14:22:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:References:To:From:Subject: Cc:Message-Id:Date:Mime-Version:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=L3pmpBtTIgS8fkd1smDmgOB494llOCjswLEl5+aSDGk=; b=16xSWR3mhU9gzS Om7Ij0L2CMH88S6ykhPMAKh9SNySA7pXt5mQK+pN9mhZBNRb6zkbcaBnaxWxYJdcgBTrKeSzp8/5n tZtvsU06JJ1p2riMrvD+/WelzTv25xPDh34JeNLZQw5N42Y3aWml3cSGRPlV/9S0mxm1xjGRrkTAi 95j+i+xLgNVil2JoYhWAaCAmmWRQYRaLz+LQ0Px37lchSi0khstu3cYYLArn38MxCGgRBQ/RT8kOQ uhgYo3OGNCFvTXQS9QzK6YNw7CNnGTC0mUQ8jt+gbp3tMX9R3SsBhc4hCKzfkZavcuihthYuS8jrG 773nHfL8A95LjXMYWdbQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vHjpR-00000003BfK-3BnL; Sat, 08 Nov 2025 14:22:09 +0000 Received: from out-189.mta1.migadu.com ([2001:41d0:203:375::bd]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vHjpM-00000003BeR-0Ihm for linux-rockchip@lists.infradead.org; Sat, 08 Nov 2025 14:22:08 +0000 Mime-Version: 1.0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cknow-tech.com; s=key1; t=1762611715; 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=LPn9l+QoDiG2QhjIafrV6sGFlG1kFs7V/OcM6xzYO04=; b=P189H++3jsjVCo2N95hPxrfBzWWByQ0uwh1OJKldQ/RBEV/5VZAgdfHmvB5vYrtufQnceg WApyA74cMwLyug8RtetofDrFbjO4cC48jNDcwONMyeACAcv0mvZh7ZnQTHA9JWew3W9ZWi qBH+ZmcO65lYR1rqmc/zMYzcY+ePOGBzLlpkSJWEtQRFD0OlobZPINuSI/Pfa3N7E2WfWU nCCihzEoTb6LsqNm1+Vx+pUpNlYVm8rgximClhXyAVtwZVUFQ52C1a15J2j7sy2BtrbfAF ZkHAeduwh8nm7yQz1YlcwyV/AAcYiwU/LwmBbOs2Z5KjF5B6UsH8uTsBVDLE8Q== Date: Sat, 08 Nov 2025 15:21:45 +0100 Message-Id: Cc: "FUKAUMI Naoki" , "Damien Le Moal" , "Anand Moon" , , , , , "Dragan Simic" , "Lorenzo Pieralisi" , =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= , "Manivannan Sadhasivam" , "Rob Herring" , "Bjorn Helgaas" , "Heiko Stuebner" Subject: Re: [PATCH] PCI: dw-rockchip: Skip waiting for link up X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: "Diederik de Haas" To: "Niklas Cassel" , "Shawn Lin" References: <20250113-rockchip-no-wait-v1-1-25417f37b92f@kernel.org> <1E8E4DB773970CB5+5a52c9e1-01b8-4872-99b7-021099f04031@radxa.com> <6e87b611-13ea-4d89-8dbf-85510dd86fa6@rock-chips.com> In-Reply-To: X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251108_062206_051168_2982BE6B X-CRM114-Status: GOOD ( 16.52 ) X-BeenThere: linux-rockchip@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Upstream kernel work for Rockchip platforms List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-rockchip" Errors-To: linux-rockchip-bounces+linux-rockchip=archiver.kernel.org@lists.infradead.org On Sat Nov 8, 2025 at 2:27 PM CET, Niklas Cassel wrote: > On Sat, Nov 08, 2025 at 01:34:32PM +0100, Niklas Cassel wrote: >> >> The pcie-dw-rockchip.c driver is modelled after the qcom driver. >> So if this is a problem when a ASM2806 switch is connected, I would >> expect qcom platforms to have the same problem. > > Looking more closely at this, comparing the "good" kernel: There's another thing that caught my eye ... > [ 1.868857] pci 0004:40:00.0: [1d87:3588] type 01 class 0x060400 PCIe Root Port > [ 1.869509] pci 0004:40:00.0: ROM [mem 0x00000000-0x0000ffff pref] > ... > [ 1.879764] pci 0004:41:00.0: enabling Extended Tags > [ 1.880614] pci 0004:41:00.0: PME# supported from D0 D3hot D3cold > [ 1.881409] pci 0004:41:00.0: 2.000 Gb/s available PCIe bandwidth, limited by 2.5 GT/s PCIe x1 link at 0004:40:00.0 (capable of 15.752 Gb/s with 8.0 GT/s PCIe x2 link) ... 2.000 Gb/s ... > [ 1.888729] pci 0004:41:00.0: bridge configuration invalid ([bus 00-00]), reconfiguring > ... > > > With the "bad" kernel: > [ 1.383075] pci 0004:40:00.0: [1d87:3588] type 01 class 0x060400 PCIe Root Port > [ 1.383738] pci 0004:40:00.0: ROM [mem 0x00000000-0x0000ffff pref] > ... > [ 1.415746] pci 0004:41:00.0: enabling Extended Tags > [ 1.416465] pci 0004:41:00.0: PME# supported from D0 D3hot D3cold > [ 1.417181] pci 0004:41:00.0: 4.000 Gb/s available PCIe bandwidth, limited by 5.0 GT/s PCIe x1 link at 0004:40:00.0 (capable of 15.752 Gb/s with 8.0 GT/s PCIe x2 link) ... 4.0000 Gb/s I don't know if that's relevant or important, but wanted to mention it. Cheers, Diederik > [ 1.423384] pci 0004:41:00.0: bridge configuration invalid ([bus 00-00]), reconfiguring > ... > > > We can see that the pcie-dw-rockchip.c driver detects the ASM2806 switch > in both cases. So the problem is not really with enumerating the root port. > > The problem seems to be that with the "bad" kernel, you get a lot of: > [ 1.464651] pci 0004:42:00.0: devices behind bridge are unusable because [bus 43] cannot be assigned for them > > Because the bus ends are different, and conflicts with each other. > I don't know why this happens. > > Perhaps we could add a quirk for ASM2806 that does some extra sleep if that > switch is detected, if for some reason, the switch is not actually ready > after the delays defined by the PCIe specification. > > (And btw. please test with the latest 6.18-rc, as, from experience, the > ASPM problems in earlier RCs can result in some weird problems that are > not immediately deduced to be caused by the ASPM enablement.) > > > Kind regards, > Niklas _______________________________________________ Linux-rockchip mailing list Linux-rockchip@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-rockchip