From patchwork Tue Nov 28 08:15:06 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johan Hovold X-Patchwork-Id: 13470603 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B414A168BA; Tue, 28 Nov 2023 08:15:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="PnNpAEzk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 54D89C433CB; Tue, 28 Nov 2023 08:15:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1701159324; bh=e1PcYzYbTNGpVaCcrOSsdIFbJOZYRYBf4r0j5u1WFhE=; h=From:To:Cc:Subject:Date:From; b=PnNpAEzkB5uqEBeZm9QHP9op3cULwxXdOCDWsdgloE72TTyngsnpeQaqHd4ea6/wt rBPumlRF9D3096Yp4PlPDqbmZ6lrflrLcD+r44/0TwQ8xl/OZ1O4j//pRgMFOMCL6s m+csegl+47y24fwx5C5bo3vzd8Z7Y7OxMXuIAyjoc+9EHVkc5y7CTh4IVAfsFfwt0M dFz+LYyFTZh7Y5xSXgiZpn7uYwL9jBBIJKr8sjUb0A7IVHFfW97Wuy9Mtk1TfpJ0uT uJ0Gf3jDknuXwjEsGwu/6kDsabz0txTwpNLrBJ6YR+s3WbwQXDO+236Ab+EXckBvTQ AlGGVsNA8QdnQ== Received: from johan by xi.lan with local (Exim 4.96.2) (envelope-from ) id 1r7tG3-00053n-2I; Tue, 28 Nov 2023 09:15:52 +0100 From: Johan Hovold To: "Lorenzo Pieralisi" , =?utf-8?q?Krzysztof_Wilczy?= =?utf-8?q?=C5=84ski?= , "Bjorn Helgaas" Cc: Andy Gross , Bjorn Andersson , Konrad Dybcio , Manivannan Sadhasivam , Rob Herring , Nirmal Patel , Jonathan Derrick , linux-arm-msm@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold Subject: [PATCH v2 0/6] PCI: Fix deadlocks when enabling ASPM Date: Tue, 28 Nov 2023 09:15:06 +0100 Message-ID: <20231128081512.19387-1-johan+linaro@kernel.org> X-Mailer: git-send-email 2.41.0 Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 The pci_enable_link_state() helper is currently only called from pci_walk_bus(), something which can lead to a deadlock as both helpers take a pci_bus_sem read lock. Add a new locked helper which can be called with the read lock held and fix up the two current users (the second is new in 6.7-rc1). Note that there are no users left of the original unlocked variant after this series, but I decided to leave it in place for now (e.g. to mirror the corresponding helpers to disable link states). Included are also a couple of related cleanups. Johan Changes in v2 - fix up the function name in a kernel doc comment as reported by the kernel test robot Johan Hovold (6): PCI/ASPM: Add locked helper for enabling link state PCI: vmd: Fix deadlock when enabling ASPM PCI: qcom: Fix deadlock when enabling ASPM PCI: qcom: Clean up ASPM comment PCI/ASPM: Clean up disable link state parameter PCI/ASPM: Add lockdep assert to link state helper drivers/pci/controller/dwc/pcie-qcom.c | 7 ++- drivers/pci/controller/vmd.c | 2 +- drivers/pci/pcie/aspm.c | 65 +++++++++++++++++++------- include/linux/pci.h | 3 ++ 4 files changed, 56 insertions(+), 21 deletions(-)