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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 55A30C5475B for ; Fri, 8 Mar 2024 13:31:35 +0000 (UTC) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=kCQZriwB; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4TrnBY73KXz3w6l for ; Sat, 9 Mar 2024 00:31:33 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=kCQZriwB; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=145.40.73.55; helo=sin.source.kernel.org; envelope-from=cassel@kernel.org; receiver=lists.ozlabs.org) Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) (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 lists.ozlabs.org (Postfix) with ESMTPS id 4Trn2r4rz4z3w5f for ; Sat, 9 Mar 2024 00:24:52 +1100 (AEDT) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sin.source.kernel.org (Postfix) with ESMTP id CF65ECE16B8; Fri, 8 Mar 2024 13:24:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E7CB0C433F1; Fri, 8 Mar 2024 13:24:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1709904288; bh=LAdBrFiiqpPIYb+1fEVGEmGjUltxM7IwFgH3jq/rJDo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=kCQZriwBir8HdF7tMJnCbXC/StQ5ZubtkrurJ/hNH5ABeLm3oUkbkLT4RFyY2E8eO WhEOBptb0FP//rwCm3NEOkHagnEj5gf5qMnmPMe/qNH0seeYsh4AqBQsrYd+RbrnH6 pDRLKSmQdbkECwUTmu2Qx8EiSpSPwjGi1C/wfhV39qWSt9mOUDcyucPUwdWxl7RKKL r8to3P6b356iIL9jCR8K8bfo8pwwI6jmqw7KiebRFq4G0i2mjya0l5XV7KTfiYE85w umqtSbSKWbmwfLY0nu5JqX3tCAiDkKwWTsmoxH+sE6t5e8phFPQm6vRX5Q9girR6xc MZOTZB3+scaNQ== Date: Fri, 8 Mar 2024 14:24:35 +0100 From: Niklas Cassel To: Manivannan Sadhasivam Subject: Re: [PATCH v9 07/10] PCI: dwc: ep: Remove "core_init_notifier" flag Message-ID: References: <20240304-pci-dbi-rework-v9-0-29d433d99cda@linaro.org> <20240304-pci-dbi-rework-v9-7-29d433d99cda@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240304-pci-dbi-rework-v9-7-29d433d99cda@linaro.org> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Vignesh Raghavendra , Kunihiko Hayashi , linux-pci@vger.kernel.org, Lorenzo Pieralisi , Frank Li , Minghuan Lian , Thierry Reding , Kishon Vijay Abraham I , Fabio Estevam , Marek Vasut , Kishon Vijay Abraham I , Rob Herring , Jesper Nilsson , linux-tegra@vger.kernel.org, linux-arm-kernel@axis.com, Jonathan Hunter , NXP Linux Team , Richard Zhu , Srikanth Thokala , linux-arm-msm@vger.kernel.org, Sascha Hauer , linuxppc-dev@lists.ozlabs.org, Bjorn Helgaas , linux-omap@vger.kernel.org, Mingkai Hu , linux-arm-kernel@ lists.infradead.org, Roy Zang , Jingoo Han , Yoshihiro Shimoda , linux-kernel@vger.kernel.org, Vidya Sagar , linux-renesas-soc@vger.kernel.org, Masami Hiramatsu , Pengutronix Kernel Team , Gustavo Pimentel , Shawn Guo , Lucas Stach Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Mon, Mar 04, 2024 at 02:52:19PM +0530, Manivannan Sadhasivam wrote: > "core_init_notifier" flag is set by the glue drivers requiring refclk from > the host to complete the DWC core initialization. Also, those drivers will > send a notification to the EPF drivers once the initialization is fully > completed using the pci_epc_init_notify() API. Only then, the EPF drivers > will start functioning. > > For the rest of the drivers generating refclk locally, EPF drivers will > start functioning post binding with them. EPF drivers rely on the > 'core_init_notifier' flag to differentiate between the drivers. > Unfortunately, this creates two different flows for the EPF drivers. > > So to avoid that, let's get rid of the "core_init_notifier" flag and follow > a single initialization flow for the EPF drivers. This is done by calling > the dw_pcie_ep_init_notify() from all glue drivers after the completion of > dw_pcie_ep_init_registers() API. This will allow all the glue drivers to > send the notification to the EPF drivers once the initialization is fully > completed. > > Only difference here is that, the drivers requiring refclk from host will > send the notification once refclk is received, while others will send it > during probe time itself. > > Reviewed-by: Frank Li > Signed-off-by: Manivannan Sadhasivam > --- > diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c > index 18c80002d3bd..fc0282b0d626 100644 > --- a/drivers/pci/endpoint/functions/pci-epf-test.c > +++ b/drivers/pci/endpoint/functions/pci-epf-test.c > @@ -927,21 +928,12 @@ static int pci_epf_test_bind(struct pci_epf *epf) > if (ret) > return ret; > Hello Mani, Since you asked for testing, I gave your series a spin (with a driver without .core_init_notifier). There seems to be a problem that pci_epc_write_header() is never called. Debugging this, it seems that .core_init in pci-epf-test is never called. If I add debug prints in pci_epc_init_notify(), I see that it does not notify a single EPF driver. It appears that the patch in $subject will call pci_epc_init_notify() at EPC driver .probe() time, and at that point in time, there are no EPF drivers registered. They get registered later, when doing the configfs write. I would say that it is the following change that breaks things: > - if (!core_init_notifier) { > - ret = pci_epf_test_core_init(epf); > - if (ret) > - return ret; > - } > - Since without this code, pci_epf_test_core_init() will no longer be called, as there is currently no one that calls epf->core_init() for a EPF driver after it has been bound. (For drivers that call dw_pcie_ep_init_notify() in .probe()) I guess one way to solve this would be for the EPC core to keep track of the current EPC "core state" (up/down). If the core is "up" at EPF .bind() time, notify the EPF driver directly after .bind()? Kind regards, Niklas