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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 42C94C74A5B for ; Thu, 30 Mar 2023 04:22:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229827AbjC3EWb (ORCPT ); Thu, 30 Mar 2023 00:22:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54362 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229738AbjC3EW3 (ORCPT ); Thu, 30 Mar 2023 00:22:29 -0400 Received: from lelv0142.ext.ti.com (lelv0142.ext.ti.com [198.47.23.249]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 64A2A1BD; Wed, 29 Mar 2023 21:22:28 -0700 (PDT) Received: from lelv0265.itg.ti.com ([10.180.67.224]) by lelv0142.ext.ti.com (8.15.2/8.15.2) with ESMTP id 32U4MBnM020441; Wed, 29 Mar 2023 23:22:11 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1680150131; bh=ICmYzhdedbmZu1l+qMzIC+i9SZvTwo0G0MLFrhFDLDE=; h=Date:CC:Subject:To:References:From:In-Reply-To; b=SekCXPtJEzk03ZukeC9odXb2WHyHmjRG4oW2iRW796NEqlPQiwKb08ZodALMVf4Dh gRCBXGr0qLJhmgv9oIITikbquHbxVhIH32tnf63Bz1pWkSnM+alkQRfYWfyHEW3Q+U zvnH2B+tNvQ41+Uw/ecS5U48WCZPcEFC07iQo1II= Received: from DFLE113.ent.ti.com (dfle113.ent.ti.com [10.64.6.34]) by lelv0265.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 32U4MBCH020708 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 29 Mar 2023 23:22:11 -0500 Received: from DFLE103.ent.ti.com (10.64.6.24) by DFLE113.ent.ti.com (10.64.6.34) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.16; Wed, 29 Mar 2023 23:22:11 -0500 Received: from fllv0040.itg.ti.com (10.64.41.20) by DFLE103.ent.ti.com (10.64.6.24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.16 via Frontend Transport; Wed, 29 Mar 2023 23:22:11 -0500 Received: from [172.24.145.61] (ileaxei01-snat2.itg.ti.com [10.180.69.6]) by fllv0040.itg.ti.com (8.15.2/8.15.2) with ESMTP id 32U4M7mx071014; Wed, 29 Mar 2023 23:22:07 -0500 Message-ID: <646f0efe-d2b6-8bda-9629-fb9615cf4b52@ti.com> Date: Thu, 30 Mar 2023 09:52:06 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.9.0 CC: , , , , , , "Raghavendra, Vignesh" , , , , , , Subject: Re: [PATCH v2] PCI: cadence: Fix Gen2 Link Retraining process To: Bjorn Helgaas References: <20230329170814.GA3067800@bhelgaas> Content-Language: en-US From: Siddharth Vadapalli In-Reply-To: <20230329170814.GA3067800@bhelgaas> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Hello Bjorn, On 29/03/23 22:38, Bjorn Helgaas wrote: > On Wed, Mar 29, 2023 at 08:11:25PM +0530, Raghavendra, Vignesh wrote: >> Hi Lorenzo, Bjorn, >> >> On 3/15/2023 12:38 PM, Siddharth Vadapalli wrote: >>> The Link Retraining process is initiated to account for the Gen2 defect in >>> the Cadence PCIe controller in J721E SoC. The errata corresponding to this >>> is i2085, documented at: >>> https://www.ti.com/lit/er/sprz455c/sprz455c.pdf >>> >>> The existing workaround implemented for the errata waits for the Data Link >>> initialization to complete and assumes that the link retraining process >>> at the Physical Layer has completed. However, it is possible that the >>> Physical Layer training might be ongoing as indicated by the >>> PCI_EXP_LNKSTA_LT bit in the PCI_EXP_LNKSTA register. >>> >>> Fix the existing workaround, to ensure that the Physical Layer training >>> has also completed, in addition to the Data Link initialization. >>> >>> Fixes: 4740b969aaf5 ("PCI: cadence: Retrain Link to work around Gen2 training defect") >>> Signed-off-by: Siddharth Vadapalli >>> Reviewed-by: Vignesh Raghavendra >>> --- >>> Changes from v1: >>> 1. Collect Reviewed-by tag from Vignesh Raghavendra. >>> 2. Rebase on next-20230315. >>> >>> v1: >>> https://lore.kernel.org/r/20230102075656.260333-1-s-vadapalli@ti.com >>> >>> .../controller/cadence/pcie-cadence-host.c | 27 +++++++++++++++++++ >>> 1 file changed, 27 insertions(+) >> >> Wondering do one of you be pulling this patch in? This patch was never >> picked for 6.3-rc1 merge cycle... Just want to make sure >> pcie-cadence*.c and pci-j721e.c patches have a path to reach pci tree. > > Yes, Lorenzo or Krzysztof will likely pick this up. I think Lorenzo > is out of the office this week. > > Drive-by comment: the current patch doesn't seem to give any > indication to the user when cdns_pcie_host_training_complete() times > out. Is that timeout potentially of interest to a user? Should there > be a log message there? Thank you for reviewing the patch. The return value of -ETIMEDOUT from the function cdns_pcie_host_training_complete() added by this patch will be handled similar to the -ETIMEDOUT from the cdns_pcie_host_wait_for_link() function that is already present. If cdns_pcie_host_training_complete() returns -ETIMEDOUT, it is returned to cdns_pcie_host_start_link() function which is called within cdns_pcie_host_setup() function. In the cdns_pcie_host_setup() function, there is already a dev_dbg() print for handling the case where cdns_pcie_host_wait_for_link() times out. For this reason, I felt that for both cases, the dev_dbg() print can be used to debug without the need for an extra log message. Please let me know if that's fine. Regards, Siddharth.