From mboxrd@z Thu Jan 1 00:00:00 1970 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 96A1B4FF7B; Mon, 18 Dec 2023 14:02:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="nmZS/0Bf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A984AC433C8; Mon, 18 Dec 2023 14:02:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1702908166; bh=e1hDEaP4ud1tjf7gNWmjw/dJVt//ty/k2fmV0Xc4D5k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nmZS/0Bfr3e8g9gUNFq4nHYTo5BX70K5bp1kg8RYP5SzDVgvIRqpYXayiHFte7Td9 ZLkZXliQooYm78VOyS+WpZ5UiZGqqUObIqeU3JaTglar5F0WX0mgNpgdEFRbNhAHBy YMYTTZVr3qMCoL7H8V7wP9lOj1BI0MUWaFjAqs4Y= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Johan Hovold , Bjorn Helgaas , Manivannan Sadhasivam , Michael Bottini , "David E. Box" Subject: [PATCH 6.6 077/166] PCI: vmd: Fix potential deadlock when enabling ASPM Date: Mon, 18 Dec 2023 14:50:43 +0100 Message-ID: <20231218135108.481814039@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231218135104.927894164@linuxfoundation.org> References: <20231218135104.927894164@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johan Hovold commit 49de0dc87965079a8e2803ee4b39f9d946259423 upstream. The vmd_pm_enable_quirk() helper is called from pci_walk_bus() during probe to enable ASPM for controllers with VMD_FEAT_BIOS_PM_QUIRK set. Since pci_walk_bus() already holds a pci_bus_sem read lock, use pci_enable_link_state_locked() to enable link states in order to avoid a potential deadlock (e.g. in case someone takes a write lock before reacquiring the read lock). Fixes: f492edb40b54 ("PCI: vmd: Add quirk to configure PCIe ASPM and LTR") Link: https://lore.kernel.org/r/20231128081512.19387-3-johan+linaro@kernel.org Signed-off-by: Johan Hovold [bhelgaas: add "potential" in subject since the deadlock has only been reported by lockdep, include helper name in commit log] Signed-off-by: Bjorn Helgaas Reviewed-by: Manivannan Sadhasivam Cc: # 6.3 Cc: Michael Bottini Cc: David E. Box Signed-off-by: Greg Kroah-Hartman --- drivers/pci/controller/vmd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c index 94ba61fe1c44..0452cbc362ee 100644 --- a/drivers/pci/controller/vmd.c +++ b/drivers/pci/controller/vmd.c @@ -751,7 +751,7 @@ static int vmd_pm_enable_quirk(struct pci_dev *pdev, void *userdata) if (!(features & VMD_FEAT_BIOS_PM_QUIRK)) return 0; - pci_enable_link_state(pdev, PCIE_LINK_STATE_ALL); + pci_enable_link_state_locked(pdev, PCIE_LINK_STATE_ALL); pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_LTR); if (!pos) -- 2.43.0