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 22FE5C77B71 for ; Tue, 18 Apr 2023 03:50:33 +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:From:References:To:Subject: CC:MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=VUce9/1PGcFKOZChRgyYAuxn8n8e/Gv9BjPZ2ADqlyQ=; b=gF0m0mbfLO7ero MfKjL8uBNvIl8Z7tzKhGxxGC5+bWo8/VU0QNnMk1w0OR3t28dkQlY1wlbePGyWR3kr9xGLEo9y+v0 QIopDyUgxXt96K2/eGcFzomC+aR6uwMgXAnU8ZGUb/5dTMr9MvvNEfhZ1h1ttHM238yla1i5SpKM+ OWno8XmhQLcYsbGmpB/XaEXN8fUuZ4EJNKitnfpVjj7WHGgvGKhORXp4kN+DSz/ZwDtnGcbd7RiE+ Zi6kR4vItHzMnWiUXbOqX3OIybD1JMpj0oZ0Tsd0T+jc+SoplweIUyRHqW5RtQNn/1YFEK/lAAiHF +tp9bnHo2RADOHYTzccg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1pocLN-000lWm-0b; Tue, 18 Apr 2023 03:49:25 +0000 Received: from lelv0142.ext.ti.com ([198.47.23.249]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1pocLJ-000lW8-25 for linux-arm-kernel@lists.infradead.org; Tue, 18 Apr 2023 03:49:23 +0000 Received: from lelv0265.itg.ti.com ([10.180.67.224]) by lelv0142.ext.ti.com (8.15.2/8.15.2) with ESMTP id 33I3nAh0038643; Mon, 17 Apr 2023 22:49:10 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1681789750; bh=CO32Djbhl7Q2nG1jrPsAUR0MdzJ0i5giMSLCdIwmiwE=; h=Date:CC:Subject:To:References:From:In-Reply-To; b=B/Aej7SnyzqvSy5u2Jty7oGyvqg5ibOAD9rkKsdGo43WTRgPoiemgFd4pG7x0wsbH C8Q0Mj/lG+S0GHJun5WU6rOUhgptGXlE6OkXfo4taKxExK4XVgQSry/8j1fopKArpD pXLh7Oi6qG6FO2t9W5Q7tpADf9ISRmqG20advFac= Received: from DLEE100.ent.ti.com (dlee100.ent.ti.com [157.170.170.30]) by lelv0265.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 33I3nA2B026282 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 17 Apr 2023 22:49:10 -0500 Received: from DLEE115.ent.ti.com (157.170.170.26) by DLEE100.ent.ti.com (157.170.170.30) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.16; Mon, 17 Apr 2023 22:49:10 -0500 Received: from lelv0326.itg.ti.com (10.180.67.84) by DLEE115.ent.ti.com (157.170.170.26) 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; Mon, 17 Apr 2023 22:49:10 -0500 Received: from [172.24.145.61] (ileaxei01-snat.itg.ti.com [10.180.69.5]) by lelv0326.itg.ti.com (8.15.2/8.15.2) with ESMTP id 33I3n6Yv018527; Mon, 17 Apr 2023 22:49:07 -0500 Message-ID: Date: Tue, 18 Apr 2023 09:19:05 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.10.0 CC: , , , , "Raghavendra, Vignesh" , , , , , , Subject: Re: [PATCH v2] PCI: cadence: Fix Gen2 Link Retraining process To: Bjorn Helgaas , , References: <20230330170218.GA3155390@bhelgaas> Content-Language: en-US From: Siddharth Vadapalli In-Reply-To: <20230330170218.GA3155390@bhelgaas> X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230417_204921_849950_0E5EF60C X-CRM114-Status: GOOD ( 28.73 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hello, Can this patch please be merged if there are no concerns? On 30/03/23 22:32, Bjorn Helgaas wrote: > On Thu, Mar 30, 2023 at 09:52:06AM +0530, Siddharth Vadapalli wrote: >> 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. > > Sounds good. > > dev_dbg() wouldn't be the right thing if we *expect* the link to come > up, but ISTR that maybe you can't detect device presence directly. If > that's the case, all you can do is try to bring the link up and assume > the slot is empty if it doesn't come up. If the usual reason for the > timeout is that the slot is empty, dev_dbg() should be fine. > > Another drive-by comment, no action needed, seems slightly strange to > have two "start_link" functions called one after the other: > > cdns_pcie_host_setup > cdns_pcie_start_link > cdns_pcie_host_start_link > > I assume both are for the same link, so it's weird to have two > functions for it. > > Bjorn -- Regards, Siddharth. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel