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 DDDCEC021AA for ; Wed, 19 Feb 2025 18:28:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:References: List-Owner; bh=hUfRF/9dSTrKR8PGuEgD33owCC+QawYNihvsUbTs4mc=; b=N80oVqMFRGcIlk 7d+GsO4Wr7KxepNNOpiQHnjdlrsnXSZAEn55EqwA0Lq4AGcGiNqNikWngH4oibJhFqUfSiPfRcT5q NnIVn6zQqYhA27oWVXlrz/6pYO/P+WGtOX/njRYQcpXwmYwMW8ZzH5lCnM4h6EM2QmD1dmUbMzphx YSyiJ9PH6NTHfpApVOwdYxXbzyZrZBnYdfN/jq0tTm1s8O2ib2lB7Ofe5wk1uKBBF/CMdqGbXhwpC zBIs2H4yogIjGHxlNDeXgjgYAZ4Z6h0FrCsfTC8VE5DEJmYFCqwQqdktGvb+jOfLfGBrPcioDaP8O RY0BFwyM7g4aOAp1/bhw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tkooF-0000000EMQ5-2NSk; Wed, 19 Feb 2025 18:28:35 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tkonW-0000000EM82-4B6F for ath11k@lists.infradead.org; Wed, 19 Feb 2025 18:27:52 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 325585C5BCB; Wed, 19 Feb 2025 18:27:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E2B6FC4CED1; Wed, 19 Feb 2025 18:27:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1739989670; bh=UIoAHLKhxXMvwRVPNUAgVWM1OzHt8bv2gL9HuSb4s8g=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=oM/7VpTzi/qHrQlMXfwp1C2byH05D8tZNakXeSfti2tjiRVCusvRpVWuFJUofaKjZ n2MkVMuuW4wNzNLERxr0VDX6bPR6a91Lo8/ONo9SmrsqvFChLUO1MTM4VwTLopoYB3 23XJT+Dnbarq/Ci0AYvXIPn2vNFu/a9FdcLD/KdzwdcAeeCyylSLoMe5mRLVctMfO1 QCcvib6Am/JwMH7sZvNuQHgfNTSfJmwSwGUsHD2UUvPIQEhRIVT0s11Iy4/93TksRK 2XMkZ3frjmXUteUMicgESwd8+nYmUp9e7fd7V6lZL8Ex/9otJIxLJ0DBtoVa5wtW/o fIVXvX6Pk78jA== Date: Wed, 19 Feb 2025 12:27:46 -0600 From: Bjorn Helgaas To: Krishna Chaitanya Chundru Cc: Bjorn Helgaas , Ilpo =?utf-8?B?SsOkcnZpbmVu?= , Jingoo Han , Manivannan Sadhasivam , Lorenzo Pieralisi , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Rob Herring , Johannes Berg , Jeff Johnson , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, mhi@lists.linux.dev, linux-wireless@vger.kernel.org, ath11k@lists.infradead.org, quic_jjohnson@quicinc.com, quic_pyarlaga@quicinc.com, quic_vbadigan@quicinc.com, quic_vpernami@quicinc.com, quic_mrana@quicinc.com Subject: Re: [PATCH 4/8] PCI: dwc: qcom: Update ICC & OPP votes based upon the requested speed Message-ID: <20250219182746.GA226108@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250219_102751_088443_B15D2E46 X-CRM114-Status: GOOD ( 14.56 ) X-BeenThere: ath11k@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "ath11k" Errors-To: ath11k-bounces+ath11k=archiver.kernel.org@lists.infradead.org On Wed, Feb 19, 2025 at 11:28:47PM +0530, Krishna Chaitanya Chundru wrote: > On 2/19/2025 3:37 AM, Bjorn Helgaas wrote: > > On Mon, Feb 17, 2025 at 12:04:11PM +0530, Krishna Chaitanya Chundru wrote: > > > QCOM PCIe controllers needs to disable ASPM before initiating link > > > re-train. So as part of pre_bw_scale() disable ASPM and as part of > > > post_scale_bus_bw() enable ASPM back. > > > > s/needs/need/ > > > > Why does Qcom need to disable ASPM? Is there a PCIe spec restriction > > about this that should be applied to all PCIe host bridges? Or is > > this a Qcom defect? > > > It is QCOM controller issue, PCIe spec doesn't mention to disable ASPM. OK. I'm a little concerned that disabling/enabling PCIE_LINK_STATE_ALL might clobber preferences set by drivers of downstream devices, but I guess ... Maybe we could add a comment in the code about this being done to work around some Qcom issue so that browsers of pci_enable_link_state_locked() don't get the idea that this needs to be done generically. Bjorn