From patchwork Wed Jan 24 09:25:33 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ajay Agarwal X-Patchwork-Id: 13528849 Received: from mail-yb1-f202.google.com (mail-yb1-f202.google.com [209.85.219.202]) (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 CB68817C62 for ; Wed, 24 Jan 2024 09:26:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706088367; cv=none; b=j4FllRyH2DIDkPExmDLkyEYu4el526Hh5AJGMLte0NMXZq6hXnyyw/AzsA0zX9vM7FHUylJllCbtldbERDCG3WCoh5KMvgwxZyh0MDzSkYpyN+KkTFjH8RL3jmf9vBAUTiYt478VrqUk8hkqygPf7yy3WEdy5vZs+WASy6jIBug= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706088367; c=relaxed/simple; bh=yFNikLmen+a8FyJL+DWGcDRPH56JYeRJ47yOImVxRrI=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=ZEoHnZHB/Y/H3Ai2rqK8WoML4tInLMmo0HHQSpPazW46pm7I6eqntZo5zPWDVot5PxjdLZZKgYypuEuUYYh9WpT9+Di+eMM3bFWxQYYAxtcWMcS4f1Y6e0sZqKLDg+7rZNei4MPoQX/yiqEbOzFtDLH/bbFdZiP3twtYoSV8a40= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--ajayagarwal.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=ErdTiBmt; arc=none smtp.client-ip=209.85.219.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--ajayagarwal.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ErdTiBmt" Received: by mail-yb1-f202.google.com with SMTP id 3f1490d57ef6-dbe9e13775aso7716585276.1 for ; Wed, 24 Jan 2024 01:26:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1706088365; x=1706693165; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=aD5F04IP2GzMz61vo2l6voOzlKXJ9JFRvBWtw7JtpAI=; b=ErdTiBmtxZK49ikaZJ5c/zC0PBsZXBY8K6GCFOdCbWc6f+ws4qWrSV90q/DEtZ62QG 4HcLUXCQyjMd74z+DisbeGzw6IbDZ5IT2NZkE53k9nnyi54IR9NLzn2cDNY6AHrY26rQ YDbaznG41BGLNzQhfe6B3PiLJNvx0R3jafC5Va46L6epCe5mffL5uTPbD3lce8x8hBJn H/KJgi5kLlYn9EOzAuywJwrnYN6k2yJrgDny3fu6v1D+AiWqh/lWRGwrFdtUXYz+7cOo V0gVrUUxe4Z3ioDV35kSMP5p/h9pgiatEeYy/N6L1qHdykCLrkVW0wiYUzbEW0fDuZLm yjaw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1706088365; x=1706693165; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=aD5F04IP2GzMz61vo2l6voOzlKXJ9JFRvBWtw7JtpAI=; b=XHXxqZSpV864lBjtYOXdxfEtFpT/62kvdgiAjE0JJKvpi568C//5K2SGuMKldH84Db bCkj3J5OXTWNENrN0WvuuM5FbWAUBFg2rOEae39Q4pbBHiaCiXxcmNWSmAiT4eoQc0dL UXGWUv7dV0jJOuSd13LqeYQJ9fgki86H9HqiQMtp8sfT9q0eLCuNU3bJpD4Pz/HykRej 5foQlCrFk4zBA0NmoV5JPlOkCgCepzzCgDQ1uvzwluddwgcH0ViESBrv1aTfPXJCCs66 sGOQFkx6EchNWn1fVCdGHIX+5jGDnCNCxEu+B45bYcj1295slv2eg/XnvVxyPcuT5VxO q/5Q== X-Gm-Message-State: AOJu0Yy5xl5M67W3YqYzv51nperay7/OGEdZUavmlUYinIDlRJNOJXDw qD5e6oPQIlHPJ5bRCI1KL2cxbWrRUZN3Y7V/MaK99yMbz9qzRS/LqYri4Wbb2vg7ZEH56wjtucd LFB/5fP9VVhmxs5Vu0G8efg== X-Google-Smtp-Source: AGHT+IGpm5pbUKRaua3G8PxDx1Ii5KdghkY8OgO/jjvezXQyRzb0EBmYxWPiqfQP1GK9R1juO+clB3FjhrvcfTFDYw== X-Received: from ajaya.c.googlers.com ([fda3:e722:ac3:cc00:4f:4b78:c0a8:39b5]) (user=ajayagarwal job=sendgmr) by 2002:a05:6902:b16:b0:dc2:4469:e9ea with SMTP id ch22-20020a0569020b1600b00dc24469e9eamr241996ybb.11.1706088364797; Wed, 24 Jan 2024 01:26:04 -0800 (PST) Date: Wed, 24 Jan 2024 14:55:33 +0530 In-Reply-To: <20240124092533.1267836-1-ajayagarwal@google.com> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240124092533.1267836-1-ajayagarwal@google.com> X-Mailer: git-send-email 2.43.0.429.g432eaa2c6b-goog Message-ID: <20240124092533.1267836-3-ajayagarwal@google.com> Subject: [PATCH v1 2/2] PCI: dwc: Wait for link up only if link is started From: Ajay Agarwal To: Jingoo Han , Johan Hovold , Manivannan Sadhasivam , Jon Hunter , Lorenzo Pieralisi , " =?utf-8?q?Krzysztof_Wilczy?= =?utf-8?q?=C5=84ski?= " , Rob Herring , Bjorn Helgaas , Manu Gautam , Doug Zobel , William McVicker , Serge Semin , Robin Murphy Cc: linux-pci@vger.kernel.org, Ajay Agarwal In dw_pcie_host_init(), regardless of whether the link has been started or not, the code waits for the link to come up. Even in cases where .start_link() is not defined the code ends up spinning in a loop for one second. Since in some systems dw_pcie_host_init() gets called during probe, this one second loop for each PCIe interface instance ends up extending the boot time. Signed-off-by: Ajay Agarwal --- This is actually patch v6 for [1] which I have made a part of the patch series. v4 [2] was applied, but then reverted [3]. The reason being v4 added a regression on some products which expect the link to not come up as a part of the probe. Since v4 returned error from dw_pcie_wait_for_link check, the probe function of these products started to fail. [1] https://lore.kernel.org/all/20240112093006.2832105-1-ajayagarwal@google.com/ [2] https://lore.kernel.org/all/20230412093425.3659088-1-ajayagarwal@google.com/ [3] https://lore.kernel.org/all/20230706082610.26584-1-johan+linaro@kernel.org/ drivers/pci/controller/dwc/pcie-designware-host.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c index 7991f0e179b2..e53132663d1d 100644 --- a/drivers/pci/controller/dwc/pcie-designware-host.c +++ b/drivers/pci/controller/dwc/pcie-designware-host.c @@ -487,14 +487,18 @@ int dw_pcie_host_init(struct dw_pcie_rp *pp) if (ret) goto err_remove_edma; - if (!dw_pcie_link_up(pci)) { + if (dw_pcie_link_up(pci)) { + dw_pcie_print_link_status(pci); + } else { ret = dw_pcie_start_link(pci); if (ret) goto err_remove_edma; - } - /* Ignore errors, the link may come up later */ - dw_pcie_wait_for_link(pci); + if (pci->ops && pci->ops->start_link) { + /* Ignore errors, the link may come up later */ + dw_pcie_wait_for_link(pci); + } + } bridge->sysdata = pp;